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Chow KL, Keating PE, Solanki K, Sapsford M, Lindsay K, O'Donnell JL. Anti-HMGCR myopathy: Diversity of clinical presentations in a national cohort in New Zealand. Semin Arthritis Rheum 2024; 68:152522. [PMID: 39079206 DOI: 10.1016/j.semarthrit.2024.152522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 05/21/2024] [Accepted: 07/08/2024] [Indexed: 09/10/2024]
Abstract
AIMS We describe the varied clinical presentations, barriers in diagnosis and outcomes of anti-HMGCR myopathy in a large national cohort. METHODS Adults found positive for serum anti-HMGCR autoantibodies via line blot or enzyme-immunoassay followed by immunoprecipitation were included in the study. RESULTS Of 75 patients identified, the records of 72 (96 %) described weakness as the presenting symptom. The records of 65 gave a reliable description of proximal weakness. In 22/65 (33.8 %) the weakness was described as predominantly or solely lower limb weakness. Forty-five of 75 (60 %) presented with a subacute onset (duration of symptoms >4 weeks -≤6 months), whilst 22/75 (29.3 %) presented with a more indolent chronic onset (duration of symptoms >6 months). Eighteen of 75 (24 %) suffered falls and 2/75 (2.7 %) had "general decline". In three patients no weakness was described: two presented with myalgia and one with a skin rash characterized as Jessner lymphocytic skin rash. Median creatine kinase at presentation was 7337 U/L (range 1050-25,500). Muscle biopsy was performed in 38 (50.7 %). Associated malignancy was infrequent. Four patients recovered without immunosuppression. Five-year and 10-year survival was 92.7 % (95 % CI 80.6-97.4 %), and 82.5 % (95 % CI 61.2-92.8 %) respectively. CONCLUSION Recurrent falls, a long prodrome and dominant lower limb proximal weakness were common in this anti-HMGCR myopathy cohort. These features overlap with frailty syndrome and sporadic inclusion body myositis emphasizing the importance of considering anti-HMGCR myopathy in that clinical context. A minority of patients recover after statin withdrawal alone.
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Affiliation(s)
- Ke Li Chow
- Department of Immunology, Canterbury Health Laboratories, Christchurch, New Zealand; Department of Immunology, NSW Health Pathology, Newcastle, NSW, Australia.
| | | | - Kamal Solanki
- Department of Rheumatology, Waikato Hospital, Hamilton, New Zealand
| | - Mark Sapsford
- Department of Rheumatology, Middlemore Hospital, Auckland, New Zealand
| | - Karen Lindsay
- Department of Immunology, Auckland City Hospital, Auckland, New Zealand; Department of Rheumatology, Auckland City Hospital, Auckland, New Zealand
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Vicino A, Veltsista D, van Alfen N. Muscle ultrasound in myopathies. Curr Opin Neurol 2024; 37:549-557. [PMID: 39051427 PMCID: PMC11377056 DOI: 10.1097/wco.0000000000001306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
PURPOSE OF REVIEW This review highlights recent developments in the field of muscle ultrasound (MUS) for the diagnosis and follow up of muscle disorders. RECENT FINDINGS The diagnostic screening capacity of quantitative grayscale analysis is still sufficient to assess children suspected of a neuromuscular disorder. A combination of visual and quantitative assessment is advised for optimal interpretation. MUS was more sensitive but less specific than MRI for detecting pathology in limb girdle dystrophies and inflammatory myopathies. New techniques such as shearwave elastography and artificial intelligence algorithms for automated image segmentation show promise but need further development for use in everyday practice.Muscle ultrasound has high correlations with clinical measures of function in skeletal and respiratory muscles and the orofacial region, in most of the myopathies and dystrophies studied. Over time, imaging changes precede changes in clinical status, making them attractive for biomarker use in trials. In Duchenne muscular dystrophy MUS was also responsive to the effects of steroid treatment. SUMMARY Muscle ultrasound is a sensitive technique to diagnose and follow up of skeletal, facial and respiratory muscles in neuromuscular disorders. Its role is both complementary to and partially overlapping with that of MRI.
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Affiliation(s)
- Alex Vicino
- Nerve-Muscle Unit, Neurology Service, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Dimitra Veltsista
- Department of Neurology, University Hospital of Patras, Patras, Greece
| | - Nens van Alfen
- Department of Neurology& Clinical Neurophysiology, Clinical Neuromuscular Imaging Group, Donders Center for Neuroscience, Radboudumc, Nijmegen, The Netherlands
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Yang H, Sun C, Ye L, Xu Y, Lin S, Peng Q, Wang G, Lu X. Association of anti-HMGCR antibodies of the IgM isotype with refractory immune-mediated necrotizing myopathy. Arthritis Res Ther 2024; 26:158. [PMID: 39261921 PMCID: PMC11389351 DOI: 10.1186/s13075-024-03387-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Accepted: 08/25/2024] [Indexed: 09/13/2024] Open
Abstract
OBJECTIVE Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) autoantibodies are one of the myositis-specific antibodies which is associated with immune-mediated necrotizing myopathy (IMNM). However, the relationship between anti-HMGCR isotypes and prognosis has not yet been fully investigated. This study was conducted to gain insight into the association between anti-HMGCR isotypes and clinical, and prognosis in IMNM patients who were positive for anti-HMGCR antibodies. METHODS Levels of anti-HMGCR isotypes (IgG, IgA and IgM) were assessed by enzyme-linked immunosorbent assay (ELISA) in 123 consecutive serum samples obtained from 71 patients who were positive for anti-HMGCR IgG at baseline. Disease activity was assessed by manual muscle testing (MMT) 8, Physician's Global Assessment (PGA) visual analog scale (VAS), and muscle VAS. RESULTS Baseline anti-HMGCR IgG levels were correlated with PGA VAS (r = 0.24; p = 0.04), muscle VAS (r = 0.32; p < 0.01), and MMT8(r=-0.24; p = 0.04), and baseline anti-HMGCR IgM levels were positively correlated with PGA VAS (r = 0.27, p = 0.02), muscle VAS (r = 0.24, p = 0.04). Anti-HMGCR IgM positive patients had a lower age of onset [29(25,46) vs. 51(33,65), p = 0.006], and a higher proportion of neck weakness (63.5% vs. 34.6%, p = 0.031) compared with anti-HMGCR IgM negative patients. Longitudinal analysis showed that the changes in anti-HMGCR IgG levels were correlated with the changes in the PGA VAS (β = 3.830; p < 0.0001), muscle VAS (β = 2.893; p < 0.0001), MMT8 (β=-19.368; p < 0.0001), and creatine kinase (CK) levels (β = 3900.05, p < 0.0001). Anti-HMGCR IgM levels were weakly correlated with anti-HMGCR IgA levels at baseline (r = 0.33, p < 0.01), and the variations in anti-HMGCR IgA levels were correlated with the changes in anti-HMGCR IgM levels during follow-up (β = 0.885; p < 0.0001). There were more patients with anti-HMGCR IgM who showed a refractory course than those who were with anti-HMGCR IgM negative (polycyclic course: 40% vs. 25%; chronic continuous course: 46.7% vs. 20.5%, p = 0.018). CONCLUSION In anti-HMGCR IgG-positive IMNM patients, the levels of anti-HMGCR IgG are associated with disease activity, and anti-HMGCR IgM is associated with refractory outcome and poor prognosis.
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Affiliation(s)
- Hongxia Yang
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
- Department of Clinical Laboratory, Peking University First Hospital, Beijing, China
| | - Chao Sun
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Lifang Ye
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Yuetong Xu
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Sang Lin
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Qinglin Peng
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Guochun Wang
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China
| | - Xin Lu
- Department of Rheumatology, Key Lab of Myositis, China-Japan Friendship Hospital, 2 Yinghua Road, Chaoyang District, Beijing, China.
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Alhammad RM, Alrehaili ML, Albulaihe HM, Aljereish SS, Alanazy MH. Clinical and genetic evaluation of hereditary myopathies in an adult Saudi cohort. BMC Neurol 2024; 24:312. [PMID: 39232665 PMCID: PMC11373090 DOI: 10.1186/s12883-024-03838-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 08/29/2024] [Indexed: 09/06/2024] Open
Abstract
BACKGROUND Diagnosis of hereditary myopathy is often challenging owing to overlapping clinical phenotypes and muscle histopathological findings. This retrospective study aimed to identify the phenotypic and genotypic spectra of hereditary myopathies at a tertiary hospital in Riyadh, Saudi Arabia. METHODS We reviewed the medical records of patients with hereditary myopathy who were evaluated between January 2018 and December 2022. RESULTS Eighty-seven patients (78 families) were included, two-thirds were men with a mean age of 35 (SD 14.2) years. Limb-girdle muscular dystrophy (LGMD) was the most prevalent clinical diagnosis (25 cases; 29%), of whom, a genetic diagnosis was achieved in 15 of 22 patients tested (68%). In genetically confirmed LGMD, the most prevalent disorders were dysferlinopathy (27%) followed by fukutin-related protein (FKRP) - related limb girdle muscular dystrophy (20%), sarcoglycanopathy (20%), lamin A/C related myopathy (13%), and calpain-3 myopathy (13%). In 26 patients with pathogenic/likely pathogenic variants, the genetic testing method was whole exome sequencing (WES) (42%), Next generation sequencing (NGS) (31%), and targeted single gene analysis (27%). The sensitivity of each genetic testing method was as follows: 100% for targeted single-gene analysis, 100% for targeted analysis of D4Z4 repeat array units, 88% for myotonic dystrophy protein kinase (DMPK) repeat expansion analysis, 42% for NGS-neuromuscular panel, and 46% for WES. CONCLUSION The prevalent types of hereditary myopathies were consistent with those reported locally and internationally. This study highlights the diagnostic yield of various molecular genetic tests for the diagnosis of hereditary myopathy in an adult cohort and the need for improved access to advanced molecular testing in cases suspected to have facioscapulohumeral muscular dystrophy (FSHD) or mitochondrial myopathies.
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Affiliation(s)
- Reem M Alhammad
- Department of Internal Medicine, College of Medicine, King Saud University, PO Box 7805, Riyadh, 11472, Saudi Arabia.
| | - Marwa L Alrehaili
- Department of Internal Medicine, College of Medicine, King Saud University, PO Box 7805, Riyadh, 11472, Saudi Arabia
- Department of Internal Medicine, King Fahad Hospital, Ministry of Health, PO Box 42210, Madina, Saudi Arabia
| | - Hana M Albulaihe
- Department of Internal Medicine, College of Medicine, King Saud University, PO Box 7805, Riyadh, 11472, Saudi Arabia
| | - Sultan S Aljereish
- Department of Internal Medicine, College of Medicine, King Saud University, PO Box 7805, Riyadh, 11472, Saudi Arabia
- Department of Internal Medicine, King Fahad Hospital Hofuf, Ministry of Health, PO Box 36441, Alahsa, Saudi Arabia
| | - Mohammed H Alanazy
- Department of Internal Medicine, College of Medicine, King Saud University, PO Box 7805, Riyadh, 11472, Saudi Arabia
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Putko B, Pestronk A, Van Stavern GP, Phan CL, Beecher G, Liewluck T. Ophthalmoparesis as an unusual manifestation of anti-3‑hydroxy-3-methyl-glutaryl-coenzyme A reductase antibody-associated myopathies. Neuromuscul Disord 2024; 42:1-4. [PMID: 38981343 DOI: 10.1016/j.nmd.2024.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 06/01/2024] [Accepted: 06/18/2024] [Indexed: 07/11/2024]
Abstract
We describe two anti-3‑hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) antibody-positive patients with treatment-responsive ophthalmoparesis. Patient 1 was a 53-year-old male with progressive proximal limb weakness, dysphagia, ptosis, and diplopia over 6 weeks and creatine kinase (CK) of 3,512 units/L. Patient 2 was a 55-year-old female with progressive proximal weakness, dysarthria, ptosis, diplopia, and dyspnea over 2 weeks with CK of 31,998 units/L. Both patients had normal thyroid studies and repetitive nerve stimulation, myopathic electromyography with fibrillation potentials, magnetic resonance imaging demonstrating abnormal enhancement of extraocular muscles, muscle biopsy showing necrotic myofibers, and positive anti-HMGCR antibodies. Patient 1 also had weakly positive anti-PM/Scl antibodies. Immunomodulatory therapies led to resolution of oculobulbar weakness and normalization of CK levels in both patients, while limb weakness resolved completely in patient 1 and partially in patient 2. These cases expand the phenotypic spectrum of anti-HMGCR antibody-associated myopathies to include subacute ophthalmoparesis with limb-girdle weakness and markedly elevated CK.
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Affiliation(s)
- Brendan Putko
- Department of Neurology, Mayo Clinic-Rochester, Rochester, MN, USA
| | - Alan Pestronk
- Department of Neurology, Washington University, St. Louis, Missouri, USA
| | - Gregory P Van Stavern
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, Missouri, USA
| | - Cecile L Phan
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, AB, Canada
| | - Grayson Beecher
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, AB, Canada.
| | - Teerin Liewluck
- Department of Neurology, Mayo Clinic-Rochester, Rochester, MN, USA.
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Llansó L, Segarra-Casas A, Domínguez-González C, Malfatti E, Kapetanovic S, Rodríguez-Santiago B, de la Calle O, Blanco R, Dobrescu A, Nascimento-Osorio A, Paipa A, Hernandez-Lain A, Jou C, Mariscal A, González-Mera L, Arteche A, Lleixà C, Caballero-Ávila M, Carbayo Á, Vesperinas A, Querol L, Gallardo E, Olivé M. Absence of Pathogenic Mutations and Strong Association With HLA-DRB1*11:01 in Statin-Naïve Early-Onset Anti-HMGCR Necrotizing Myopathy. NEUROLOGY(R) NEUROIMMUNOLOGY & NEUROINFLAMMATION 2024; 11:e200285. [PMID: 39106428 PMCID: PMC11309561 DOI: 10.1212/nxi.0000000000200285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 05/30/2024] [Indexed: 08/09/2024]
Abstract
BACKGROUND AND OBJECTIVES Immune-mediated necrotizing myopathy (IMNM) caused by antibodies against 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) is an inflammatory myopathy that has been epidemiologically correlated with previous statin exposure. We characterized in detail a series of 11 young statin-naïve patients experiencing a chronic disease course mimicking a limb-girdle muscular dystrophy. With the hypothesis that HMGCR upregulation may increase immunogenicity and trigger the production of autoantibodies, our aim was to expand pathophysiologic knowledge of this distinct phenotype. METHODS Clinical and epidemiologic data, autoantibody titers, creatine kinase (CK) levels, response to treatment, muscle imaging, and muscle biopsies were assessed. HMGCR expression in patients' muscle was assessed by incubating sections of affected patients with purified anti-HMGCR+ serum. Whole-exome sequencing (WES) with a special focus on cholesterol biosynthesis-related genes and high-resolution human leukocyte antigen (HLA) typing were performed. RESULTS Patients, aged 3-25 years and mostly female (90.9%), presented with subacute proximal weakness progressing over many years and high CK levels (>1,000 U/L). Diagnostic delay ranged from 3 to 27 years. WES did not reveal any pathogenic variants. HLA-DRB1*11:01 carrier frequency was 60%, a significantly higher proportion than in the control population. No upregulation or mislocalization of the enzyme in statin-exposed or statin-naïve anti-HMGCR+ patients was observed, compared with controls. DISCUSSION WES of a cohort of patients with dystrophy-like anti-HMGCR IMNM did not reveal any common rare variants of any gene, including cholesterol biosynthesis-related genes. HLA analysis showed a strong association with HLA-DRB1*11:01, previously mostly described in statin-exposed adult patients; consequently, a common immunogenic predisposition should be suspected, irrespective of statin exposure. Moreover, we were unable to conclusively demonstrate muscle upregulation/mislocalization of HMGCR in IMNM, whether or not driven by statins.
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Affiliation(s)
- Laura Llansó
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Alba Segarra-Casas
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Cristina Domínguez-González
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Edoardo Malfatti
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Solange Kapetanovic
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Benjamín Rodríguez-Santiago
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Oscar de la Calle
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Rosa Blanco
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Amelia Dobrescu
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Andrés Nascimento-Osorio
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Andrés Paipa
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Aurelio Hernandez-Lain
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Cristina Jou
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Anaís Mariscal
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Laura González-Mera
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Ana Arteche
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Cinta Lleixà
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Marta Caballero-Ávila
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Álvaro Carbayo
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Ana Vesperinas
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Luis Querol
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Eduard Gallardo
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
| | - Montse Olivé
- From the Department of Neurology (L.L., C.L., M.C.-Á., Á.C., A.V., L.Q., E.G., M.O.), Neuromuscular Diseases Unit; Department of Genetics (A.S.-C., B.R.-S.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Department of Neurology (C.D.-G.), Neuromuscular Diseases Unit, Hospital Universitario 12 de Octubre. Research Institute imas12, Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain; Université Paris-Est Créteil (E.M.), INSERM, U955 IMRB; AP-HP, Hôpital Mondor, FHU SENEC, Service d'Histologie, Créteil, France; Department of Neurology (S.K.), Neuromuscular Diseases Unit, Osakidetza Basque Health Service, Basurto University Hospital, Universidad del País Vasco, Bilbao; Institut de Recerca Sant Pau (IR Sant Pau) (B.R.-S., R.B., C.L., L.Q., E.G., M.O.), Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Madrid; Genomic Instability Syndromes and DNA Repair Group and Join Research Unit on Genomic Medicine UAB (B.R.-S.), Institut de Recerca Sant Pau (IR Sant Pau), Hospital de la Santa Creu i Sant Pau; Immunology Department (O.C., A.M.), Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Institut de Recerca Sant Pau (IR Sant Pau), Barcelona, Spain; Department of Genetics (A.D.), Craiova University Hospital, Romania; Neuropaediatrics Department (A.N.O.), Neuromuscular Diseases Unit, Hospital Sant Joan de Déu, Fundación Sant Joan de Déu, CIBERER - ISC III; Neurology Department (A.P., L.G.-M.), Neuromuscular Unit, IDIBELL-Hospital de Bellvitge, Hospitalet de Llobregat, Barcelona; Pathology Department (A.H.-L.), Neuropathology Unit, Hospital Universitario 12 de Octubre, Madrid; Pathology Department (C.J.), Institut Pediàtric de Recerca, Hospital Sant Joan de Déu, and MetabERN, Barcelona; Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid; Department of Neurology (L.G.-M.), Hospital de Viladecans, Barcelona; and Department of Genetics (A.A.), Hospital Universitario 12 de Octubre, Research Institute imas12, Madrid, Spain
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Rastegar TF, Khan IA, Christopher-Stine L. Decoding the Intricacies of Statin-Associated Muscle Symptoms. Curr Rheumatol Rep 2024; 26:260-268. [PMID: 38575845 DOI: 10.1007/s11926-024-01143-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2024] [Indexed: 04/06/2024]
Abstract
PURPOSE OF REVIEW Hyperlipidemia is the major cardiovascular morbidity and mortality risk factor. Statins are the first-line treatment for hyperlipidemia. Statin-associated muscle symptoms (SAMS) are the main reason for the discontinuation of statins among patients. The purpose of this review is to guide clinicians to recognize the difference between self-limited and autoimmune statin myopathy in addition to the factors that potentiate them. Finally, treatment strategies will be discussed. This review mostly focuses on new data in the past 3 years. RECENT FINDINGS Recent findings suggest that SAMS is a complex and multifactorial condition that involves mitochondrial dysfunction, oxidative stress, and immune-mediated mechanisms. Effective management of SAMS requires a thorough evaluation of the patient's symptoms, risk factors, and medication history, as well as consideration of alternative treatment options. While statins are effective in reducing the risk of cardiovascular events, their use is associated with a range of adverse effects, including SAMS.
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Affiliation(s)
- Tara Fallah Rastegar
- Johns Hopkins Myositis Center, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Imtiaz Ahmed Khan
- Department of Internal Medicine, Texas Tech University Health Science Center, Amarillo, TX, USA
| | - Lisa Christopher-Stine
- Johns Hopkins Myositis Center, Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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8
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Gunasekaran M, Littel HR, Wells NM, Turner J, Campos G, Venigalla S, Estrella EA, Ghosh PS, Daugherty AL, Stafki SA, Kunkel LM, Foley AR, Donkervoort S, Bönnemann CG, Toledo-Bravo de Laguna L, Nascimento A, Benito DND, Draper I, Bruels CC, Pacak CA, Kang PB. Effects of HMGCR deficiency on skeletal muscle development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.06.591934. [PMID: 38903061 PMCID: PMC11188090 DOI: 10.1101/2024.05.06.591934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Pathogenic variants in HMGCR were recently linked to a limb-girdle muscular dystrophy (LGMD) phenotype. The protein product HMG CoA reductase (HMGCR) catalyzes a key component of the cholesterol synthesis pathway. The two other muscle diseases associated with HMGCR, statin-associated myopathy (SAM) and autoimmune anti-HMGCR myopathy, are not inherited in a Mendelian pattern. The mechanism linking pathogenic variants in HMGCR with skeletal muscle dysfunction is unclear. We knocked down Hmgcr in mouse skeletal myoblasts, knocked down hmgcr in Drosophila, and expressed three pathogenic HMGCR variants (c.1327C>T, p.Arg443Trp; c.1522_1524delTCT, p.Ser508del; and c.1621G>A, p.Ala541Thr) in Hmgcr knockdown mouse myoblasts. Hmgcr deficiency was associated with decreased proliferation, increased apoptosis, and impaired myotube fusion. Transcriptome sequencing of Hmgcr knockdown versus control myoblasts revealed differential expression involving mitochondrial function, with corresponding differences in cellular oxygen consumption rates. Both ubiquitous and muscle-specific knockdown of hmgcr in Drosophila led to lethality. Overexpression of reference HMGCR cDNA rescued myotube fusion in knockdown cells, whereas overexpression of the pathogenic variants of HMGCR cDNA did not. These results suggest that the three HMGCR-related muscle diseases share disease mechanisms related to skeletal muscle development.
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Koumas C, Michelassi F. Immune-Mediated Necrotizing Myopathies: Current Landscape. Curr Neurol Neurosci Rep 2024; 24:141-150. [PMID: 38589696 DOI: 10.1007/s11910-024-01337-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2024] [Indexed: 04/10/2024]
Abstract
PURPOSE OF REVIEW Immune-mediated necrotizing myopathy (IMNM), characterized by acute or subacute onset, severe weakness, and elevated creatine kinase levels, poses diagnostic and therapeutic challenges. This article provides a succinct overview of IMNM, including clinical features, diagnostic strategies, and treatment approaches. RECENT FINDINGS Recent insights highlight the different clinical presentations and therapeutic options of IMNM stratified by autoantibody positivity and type. Additionally, recent findings call into question the reported link between statin use and IMNM. This review synthesizes current knowledge on IMNM, emphasizing its distinct clinical features and challenging management. The evolving understanding of IMNM underscores the need for a comprehensive diagnostic approach that utilizes a growing range of modalities. Early and aggressive immunomodulatory therapy remains pivotal. Ongoing research aims to refine diagnostic tools and therapeutic interventions for this challenging muscle disorder, underscoring the importance of advancing our understanding to enhance patient outcomes.
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Affiliation(s)
- Christoforos Koumas
- Department of Neurology, Columbia University Medical Center, New York, NY, USA.
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10
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D'Costa MS, Bugiardini E, Merve A, Morrow JM. PYROXD1-associated myopathy. BMJ Case Rep 2024; 17:e259907. [PMID: 38553017 PMCID: PMC10982700 DOI: 10.1136/bcr-2024-259907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024] Open
Abstract
PYROXD1-associated myopathy is a rare genetic form of limb-girdle muscular dystrophy (LGMD) with only 23 previous cases having been reported in the literature. The exact role of PYROXD1 in the pathophysiology of LGMD remains unclear. We describe two brothers who presented to the neuromuscular clinic with progressive weakness of their upper and lower limbs over the preceding decades. Our case highlights how recent advancements in genetic sequencing have revolutionised the diagnostic classification process for LGMD and provided opportunities to establish diagnoses for previously unclassified myopathies. We also illustrate how the increased adoption of muscle MRI to identify disease and target muscle biopsy can provide better quality and more informative samples for classification. Finally, our report details the clinical and histopathological findings found in both cases adding valuable data to the currently limited information published on PYROXD1-associated myopathy.
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Affiliation(s)
| | - Enrico Bugiardini
- Queen Square Centre for Neuromuscular Diseases, Queen Square UCL Institute of Neurology, London, UK
| | - Ashirwad Merve
- Neuropathology, Great Ormond Street Hospital for Children, London, UK
| | - Jasper M Morrow
- Queen Square Centre for Neuromuscular Diseases, Queen Square UCL Institute of Neurology, London, UK
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11
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Cavusoglu D, Talim B, Ekinci G, Topaloglu H. Six Years Follow-Up of an 11-Year-Old Girl with Anti-HMGCR Myopathy. J Neuromuscul Dis 2024; 11:883-887. [PMID: 38759023 PMCID: PMC11307026 DOI: 10.3233/jnd-240022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2024] [Indexed: 05/19/2024]
Abstract
Anti-HMGCR myopathy is decribed as an immune-mediated necrotizing myopathy which is characterised by subacute, progressive proximal muscle weakness and elevated creatine kinase (CK) level. In pediatric population, anti-HMGCR myopathy has been reported solely as small case reports, albeit rare. Although treatment consensus has not yet been established, proper treatment with several immunomodulators to include IVIg can show remarkable improvement. We report an 11-year-old-girl diagnosed with anti-HMGCR myopathy with 6 years of follow-up.
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Affiliation(s)
- Dilek Cavusoglu
- Department of Pediatric Neurology, Faculty of Medicine, Afyonkarahisar Health Sciences University, Afyon, Turkey
| | - Beril Talim
- Department of Pediatrics, Pathology Unit, Hacettepe University, Ankara, Turkey
| | - Gazanfer Ekinci
- Department of Radiology, Yeditepe University School of Medicine, Istanbul, Turkey
| | - Haluk Topaloglu
- Department of Pediatrics, Yeditepe University, Istanbul, Turkey
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Khoo T, Chinoy H. Anti-HMGCR immune-mediated necrotising myopathy: Addressing the remaining issues. Autoimmun Rev 2023; 22:103468. [PMID: 37884200 DOI: 10.1016/j.autrev.2023.103468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 10/23/2023] [Indexed: 10/28/2023]
Abstract
The discovery of autoantibodies directed against the 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) enzyme has defined a sub-set of immune-mediated necrotising myopathy (IMNM) which is strongly associated with exposure to statin medications. Although understanding of anti-HMGCR IMNM has grown considerably with the reporting of multiple cohorts in North America, Europe, Asia and Oceania, there remain many unanswered questions. The true incidence of anti-HMGCR IMNM is not known and heterogeneity of phenotype and treatment response within this autoantibody sub-group is being increasingly recognised. Statin-naïve adults and juvenile patients with anti-HMGCR potentially share characteristics distinct from statin-exposed patients, alluding to unique pathogenesis. Conflicting data exists on whether malignancies are associated with anti-HMGCR and further clarification is required to determine the degree of cancer screening required. Treatment approaches to anti-HMGCR IMNM are heterogeneous but generally highlight the efficacy of intravenous immunoglobulin. Even with multimodal immunosuppression, patients with anti-HMGCR remain prone to relapse, with younger patients generally manifesting more refractory disease. In this Review, we aim to summarise the current literature on anti-HMGCR and discuss the remaining issues.
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Affiliation(s)
- Thomas Khoo
- Division of Musculoskeletal and Dermatological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; School of Medicine, Faculty of Health and Medical Sciences, The University of Adelaide, South Australia, Australia; Department of Rheumatology, Salford Royal Hospital, Northern Care Alliance NHS Foundation Trust, Manchester Academic Health Science Centre, Salford, United Kingdom.
| | - Hector Chinoy
- Division of Musculoskeletal and Dermatological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Department of Rheumatology, Salford Royal Hospital, Northern Care Alliance NHS Foundation Trust, Manchester Academic Health Science Centre, Salford, United Kingdom
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13
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Zhu X, Hao J, Zhang H, Chi M, Wang Y, Huang J, Xu R, Xincai Z, Xin B, Sun X, Zhang J, Zhou S, Cheng D, Yuan T, Ding J, Zheng S, Guo C, Yang Q. Oncometabolite D-2-hydroxyglutarate-dependent metabolic reprogramming induces skeletal muscle atrophy during cancer cachexia. Commun Biol 2023; 6:977. [PMID: 37741882 PMCID: PMC10518016 DOI: 10.1038/s42003-023-05366-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 09/15/2023] [Indexed: 09/25/2023] Open
Abstract
Cancer cachexia is characterized by weight loss and skeletal muscle wasting. Based on the up-regulation of catabolism and down-regulation of anabolism, here we showed genetic mutation-mediated metabolic reprogramming in the progression of cancer cachexia by screening for metabolites and investigating their direct effect on muscle atrophy. Treatment with 93 μM D-2-hydroxyglutarate (D2HG) resulted in reduced myotube width and increased expression of E3 ubiquitin ligases. Isocitrate Dehydrogenase 1 (IDH1) mutant patients had higher D2HG than non-mutant patients. In the in vivo murine cancer cachexia model, mutant IDH1 in CT26 cancer cells accelerated cachexia progression and worsened overall survival. Transcriptomics and metabolomics revealed a distinct D2HG-induced metabolic imbalance. Treatment with the IDH1 inhibitor ivosidenib delayed the progression of cancer cachexia in murine GL261 glioma model and CT26 colorectal carcinoma models. These data demonstrate the contribution of IDH1 mutation mediated D2HG accumulation to the progression of cancer cachexia and highlight the individualized treatment of IDH1 mutation associated cancer cachexia.
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Affiliation(s)
- Xinting Zhu
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Juan Hao
- Department of Endocrinology, Shanghai Traditional Chinese Medicine, Integrated Hospital, Shanghai University of Traditional Chinese Medicine, 230 Baoding Road, Shanghai, 200082, China
| | - Hong Zhang
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Mengyi Chi
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Yaxian Wang
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Jinlu Huang
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Rong Xu
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Zhao Xincai
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Bo Xin
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Xipeng Sun
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Jianping Zhang
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Shumin Zhou
- Institution of microsurgery on extremities, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Dongdong Cheng
- Department of Bone Oncology, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of MedicineShanghai Shanghai, Shanghai, P. R. China
| | - Ting Yuan
- Department of Bone Oncology, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of MedicineShanghai Shanghai, Shanghai, P. R. China
| | - Jun Ding
- Department of Neurosurgery, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Shuier Zheng
- Department of Oncology, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Cheng Guo
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
| | - Quanjun Yang
- Department of Pharmacy, Shanghai Sixth People's Hospital affiliated Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
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14
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Oh EK, Lee SA, Lee HJ, Cha YJ, Kim S, Lee HS, Suh BC, Shin HY, Kim SW, Yoon BA, Oh SI, Kim YH, Cho JY, Cho JH, Kwon KH, Choi YC, Park HJ. Clinical and Radiological Features of Korean Patients With Anti-HMGCR Myopathy. J Clin Neurol 2023; 19:460-468. [PMID: 36929062 PMCID: PMC10471552 DOI: 10.3988/jcn.2022.0374] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/10/2022] [Accepted: 11/10/2022] [Indexed: 03/15/2023] Open
Abstract
BACKGROUND AND PURPOSE To understand the characteristics of Korean patients with anti-3-hydroxy-3-methylglutaryl-coenxyme A reductase (HMGCR) myopathy, we measured anti-HMGCR antibodies and analyzed the clinical, radiological, and pathological features of patients with anti-HMGCR myopathy. METHODS We measured titers of anti-HMGCR antibodies in the sera of 99 patients with inflammatory myopathy, 36 patients with genetic myopathy, and 63 healthy subjects using an enzyme-linked immunosorbent assay. We tested 16 myositis-specific autoantibodies (MSAs) in all patients with anti-HMGCR myopathy. RESULTS Positivity for the anti-HMGCR antibody was observed in 17 (4 males and 13 females) of 99 patients with inflammatory myopathy. The median age at symptom onset was 60 years. Ten (59%) of the patients with anti-HMGCR positivity had taken statins. The titer of anti-HMGCR antibodies was significantly higher in the statin-naïve group (median=230 U/mL, interquartile range=170-443 U/mL) than in the statin-exposed group (median=178 U/mL, interquartile range=105-210 U/mL, p=0.045). The most common symptom was proximal muscle weakness in 15 patients (88%), followed by myalgia in 9 (53%), neck weakness in 4 (24%), dysphagia in 3 (18%), and skin lesions in 2 (12%). The median titer of anti-HMGCR antibody was 202 U/mL. We found eight different MSAs in nine (53%) patients. The median disease duration from symptom onset to diagnosis was significantly shorter in the MSA-positive group than in the MSA-negative group (p=0.027). CONCLUSIONS Our study was the first to measure anti-HMGCR antibodies in inflammatory myopathy. It has provided new findings, including the suggestion of the coexistence of other MSAs in Korean patients.
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Affiliation(s)
- Eun Kyoung Oh
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Seung-Ah Lee
- Department of Neurology, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, Korea
| | - Hyun Joon Lee
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Yoon Jin Cha
- Department of Pathology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Sungjun Kim
- Department of Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hyung-Soo Lee
- Department of Neurology, Korea University Ansan Hospital, Ansan, Korea
| | - Bum Chun Suh
- Department of Neurology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Ha Young Shin
- Department of Neurology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Seung Woo Kim
- Department of Neurology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Byeol-A Yoon
- Department of Neurology, Peripheral Neuropathy Research Center, College of Medicine, Dong-A University, Busan, Korea
| | - Seong-Il Oh
- Department of Neurology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | - Yoo Hwan Kim
- Department of Neurology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
| | - Joong-Yang Cho
- Department of Neurology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - Jeong Hee Cho
- Department of Neurology, National Health Insurance Service Ilsan Hospital, Goyang, Korea
| | - Ki-Han Kwon
- Department of Neurology, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Korea
| | - Young-Chul Choi
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
- Rehabilitation Institute of Neuromuscular Disease, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hyung Jun Park
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
- Rehabilitation Institute of Neuromuscular Disease, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
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15
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Morales-Rosado JA, Schwab TL, Macklin-Mantia SK, Foley AR, Pinto E Vairo F, Pehlivan D, Donkervoort S, Rosenfeld JA, Boyum GE, Hu Y, Cong ATQ, Lotze TE, Mohila CA, Saade D, Bharucha-Goebel D, Chao KR, Grunseich C, Bruels CC, Littel HR, Estrella EA, Pais L, Kang PB, Zimmermann MT, Lupski JR, Lee B, Schellenberg MJ, Clark KJ, Wierenga KJ, Bönnemann CG, Klee EW. Bi-allelic variants in HMGCR cause an autosomal-recessive progressive limb-girdle muscular dystrophy. Am J Hum Genet 2023; 110:989-997. [PMID: 37167966 PMCID: PMC10257193 DOI: 10.1016/j.ajhg.2023.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 04/19/2023] [Indexed: 05/13/2023] Open
Abstract
Statins are a mainstay intervention for cardiovascular disease prevention, yet their use can cause rare severe myopathy. HMG-CoA reductase, an essential enzyme in the mevalonate pathway, is the target of statins. We identified nine individuals from five unrelated families with unexplained limb-girdle like muscular dystrophy and bi-allelic variants in HMGCR via clinical and research exome sequencing. The clinical features resembled other genetic causes of muscular dystrophy with incidental high CPK levels (>1,000 U/L), proximal muscle weakness, variable age of onset, and progression leading to impaired ambulation. Muscle biopsies in most affected individuals showed non-specific dystrophic changes with non-diagnostic immunohistochemistry. Molecular modeling analyses revealed variants to be destabilizing and affecting protein oligomerization. Protein activity studies using three variants (p.Asp623Asn, p.Tyr792Cys, and p.Arg443Gln) identified in affected individuals confirmed decreased enzymatic activity and reduced protein stability. In summary, we showed that individuals with bi-allelic amorphic (i.e., null and/or hypomorphic) variants in HMGCR display phenotypes that resemble non-genetic causes of myopathy involving this reductase. This study expands our knowledge regarding the mechanisms leading to muscular dystrophy through dysregulation of the mevalonate pathway, autoimmune myopathy, and statin-induced myopathy.
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Affiliation(s)
- Joel A Morales-Rosado
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Quantitative Health Sciences, Division of Computational Biology, Mayo Clinic, Rochester, MN, USA
| | - Tanya L Schwab
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MM, USA
| | - Sarah K Macklin-Mantia
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Clinical Genomics at Mayo Clinic, Jacksonville, FL, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Filippo Pinto E Vairo
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA; Division of Neurology and Developmental Neuroscience and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA; Baylor Genetics Laboratories, Houston, TX, USA
| | - Grace E Boyum
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MM, USA
| | - Ying Hu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Anh T Q Cong
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MM, USA
| | - Timothy E Lotze
- Division of Neurology and Developmental Neuroscience and Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Carrie A Mohila
- Department of Pathology & Immunology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Dimah Saade
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Diana Bharucha-Goebel
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA; Division of Neurology, Children's National Hospital, Washington, DC, USA
| | - Katherine R Chao
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Christopher Grunseich
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Christine C Bruels
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Hannah R Littel
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Elicia A Estrella
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Lynn Pais
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA; Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, USA; Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Michael T Zimmermann
- Bioinformatics Research and Development Laboratory, Genomics Sciences and Precision Medicine Center, Clinical and Translational Sciences Institute, Medical College of Wisconsin, Milwaukee, WI, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA
| | | | - Karl J Clark
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MM, USA
| | - Klaas J Wierenga
- Department of Clinical Genomics at Mayo Clinic, Jacksonville, FL, USA
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD, USA
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA; Department of Quantitative Health Sciences, Division of Computational Biology, Mayo Clinic, Rochester, MN, USA; Department of Clinical Genomics, Mayo Clinic, Rochester, MN, USA.
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16
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Chen BH, Zhu XM, Xie L, Hu HQ. Immune-mediated necrotizing myopathy: Report of two cases. World J Clin Cases 2023; 11:3552-3559. [PMID: 37383916 PMCID: PMC10294185 DOI: 10.12998/wjcc.v11.i15.3552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/25/2023] [Accepted: 04/24/2023] [Indexed: 05/25/2023] Open
Abstract
BACKGROUND Immune-mediated necrotizing myopathy is a rare autoimmune myopathy characterized by muscle weakness and elevated serum creatine kinase, with unique skeletal muscle pathology and magnetic resonance imaging features.
CASE SUMMARY In this paper, two patients are reported: One was positive for anti-signal recognition particle antibody, and the other was positive for anti-3-hydroxy-3-methylglutaryl coenzyme A reductase antibody.
CONCLUSION The clinical characteristics and treatment of the two patients were analysed, and the literature was reviewed to improve the recognition, diagnosis, and treatment of this disease.
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Affiliation(s)
- Bi-Hong Chen
- Department of Clinical Medicine, Weifang Medical University, Weifang 261053, Shandong Province, China
| | - Xue-Min Zhu
- School of Clinical Medicine, Weifang Medical University, Weifang 261053, Shandong Province, China
| | - Lei Xie
- School of Clinical Medicine, Weifang Medical University, Weifang 261053, Shandong Province, China
| | - Huai-Qiang Hu
- Department of Neurology, The 960th Hospital of People′s Liberation Army, Jinan 250031, Shandong Province, China
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17
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Dallevet CA, Benveniste O, Allenbach Y. Pathogenesis and Treatment in IMNM. CURRENT TREATMENT OPTIONS IN RHEUMATOLOGY 2023. [DOI: 10.1007/s40674-023-00201-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
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18
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De Paepe B. Incorporating circulating cytokines into the idiopathic inflammatory myopathy subclassification toolkit. Front Med (Lausanne) 2023; 10:1130614. [PMID: 37007787 PMCID: PMC10061103 DOI: 10.3389/fmed.2023.1130614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/03/2023] [Indexed: 03/18/2023] Open
Abstract
Extensive diagnostic delays and deferred treatment impact the quality of life of patients suffering from an idiopathic inflammatory myopathy. In-depth subtyping of patients is a necessary effort to engage appropriate disease management and may require specialized and elaborate evaluation of the complex spectrum of clinical and pathological disease features. Blood samples are routinely taken for diagnostic purposes, with creatine kinase measurement and autoantibody typing representing standard diagnostic tools in the clinical setting. However, for many patients the diagnostic odyssey includes the invasive and time-consuming procedure of taking a muscle biopsy. It is proposed that further implementation of blood-based disease biomarkers represents a convenient alternative approach with the potential to reduce the need for diagnostic muscle biopsies substantially. Quantification of judicious combinations of circulating cytokines could be added to the diagnostic flowchart, and growth differentiation factor 15 and C-X-C motif chemokine ligand 10 come forward as particularly good candidates. These biomarkers can offer complementary information for diagnosis indicative of disease severity, therapeutic response and prognosis.
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19
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Farini A, Tripodi L, Villa C, Strati F, Facoetti A, Baselli G, Troisi J, Landolfi A, Lonati C, Molinaro D, Wintzinger M, Gatti S, Cassani B, Caprioli F, Facciotti F, Quattrocelli M, Torrente Y. Microbiota dysbiosis influences immune system and muscle pathophysiology of dystrophin-deficient mice. EMBO Mol Med 2023; 15:e16244. [PMID: 36533294 PMCID: PMC9994487 DOI: 10.15252/emmm.202216244] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 11/24/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a progressive severe muscle-wasting disease caused by mutations in DMD, encoding dystrophin, that leads to loss of muscle function with cardiac/respiratory failure and premature death. Since dystrophic muscles are sensed by infiltrating inflammatory cells and gut microbial communities can cause immune dysregulation and metabolic syndrome, we sought to investigate whether intestinal bacteria support the muscle immune response in mdx dystrophic murine model. We highlighted a strong correlation between DMD disease features and the relative abundance of Prevotella. Furthermore, the absence of gut microbes through the generation of mdx germ-free animal model, as well as modulation of the microbial community structure by antibiotic treatment, influenced muscle immunity and fibrosis. Intestinal colonization of mdx mice with eubiotic microbiota was sufficient to reduce inflammation and improve muscle pathology and function. This work identifies a potential role for the gut microbiota in the pathogenesis of DMD.
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Affiliation(s)
- Andrea Farini
- Neurology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoMilanItaly
| | - Luana Tripodi
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Dino Ferrari CenterUniversity of MilanMilanItaly
| | - Chiara Villa
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Dino Ferrari CenterUniversity of MilanMilanItaly
| | - Francesco Strati
- Mucosal Immunology Lab, Department of Experimental OncologyIEO‐European Institute of OncologyMilanItaly
| | - Amanda Facoetti
- Humanitas UniversityMilanItaly
- Humanitas Clinical and Research Center IRCCSMilanItaly
| | - Guido Baselli
- Translational Medicine – Department of Transfusion Medicine and HematologyFondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoMilanItaly
- Present address:
SciLifeLab, Department of Microbiology, Tumor and Cell BiologyKarolinska InstitutetSolnaSweden
| | - Jacopo Troisi
- Department of Medicine, Surgery and Dentistry, Scuola Medica SalernitanaUniversity of SalernoBaronissiItaly
- Theoreo Srl, Spinoff Company of the University of SalernoMontecorvino PuglianoItaly
| | - Annamaria Landolfi
- Department of Medicine, Surgery and Dentistry, Scuola Medica SalernitanaUniversity of SalernoBaronissiItaly
- Theoreo Srl, Spinoff Company of the University of SalernoMontecorvino PuglianoItaly
| | - Caterina Lonati
- Center for Surgical ResearchFondazione IRCCS Ca' Granda, Ospedale Maggiore PoliclinicoMilanItaly
| | - Davide Molinaro
- Neurology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoMilanItaly
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Dino Ferrari CenterUniversity of MilanMilanItaly
| | - Michelle Wintzinger
- Molecular Cardiovascular Biology Division, Heart InstituteCincinnati Children's Hospital Medical CenterCincinnatiOHUSA
- Department of PediatricsUniversity of Cincinnati College of MedicineCincinnatiOHUSA
| | - Stefano Gatti
- Center for Surgical ResearchFondazione IRCCS Ca' Granda, Ospedale Maggiore PoliclinicoMilanItaly
| | - Barbara Cassani
- Humanitas Clinical and Research Center IRCCSMilanItaly
- Department of Medical Biotechnologies and Translational MedicineUniversità Degli Studi di MilanoMilanItaly
| | - Flavio Caprioli
- Unit of Gastroenterology and Endoscopy, Department of Pathophysiology and TransplantationUniversità degli Studi di Milano, Fondazione IRCCS Ca' Granda, Ospedale Policlinico di MilanoMilanItaly
| | - Federica Facciotti
- Unit of Gastroenterology and Endoscopy, Department of Pathophysiology and TransplantationUniversità degli Studi di Milano, Fondazione IRCCS Ca' Granda, Ospedale Policlinico di MilanoMilanItaly
| | - Mattia Quattrocelli
- Molecular Cardiovascular Biology Division, Heart InstituteCincinnati Children's Hospital Medical CenterCincinnatiOHUSA
- Department of PediatricsUniversity of Cincinnati College of MedicineCincinnatiOHUSA
| | - Yvan Torrente
- Neurology UnitFondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoMilanItaly
- Stem Cell Laboratory, Department of Pathophysiology and Transplantation, Dino Ferrari CenterUniversity of MilanMilanItaly
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20
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Harel T. Rare disease informs mechanism and possible treatment of statin-associated myopathy. Proc Natl Acad Sci U S A 2023; 120:e2300988120. [PMID: 36848568 PMCID: PMC10013738 DOI: 10.1073/pnas.2300988120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Affiliation(s)
- Tamar Harel
- Department of Genetics, Hadassah Medical Center, Jerusalem91120, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem91120, Israel
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21
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Muscle MRI in immune-mediated necrotizing myopathy (IMNM): implications for clinical management and treatment strategies. J Neurol 2023; 270:960-974. [PMID: 36329184 PMCID: PMC9886642 DOI: 10.1007/s00415-022-11447-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVES Immune-mediated necrotizing myopathy (IMNM) is the most severe idiopathic inflammatory myopathy (IIM) and early aggressive poly-immunotherapy is often required to reduce long-term disability. The aim of this study is to investigate muscle MRI in IMNM as outcome measure for disease activity, severity, progression, response to treatment, and to better characterize the pattern of muscle involvement. METHODS This is a retrospective, observational, cross-sectional, and longitudinal study including 22 IMNM patients, divided into three groups based on timing of first MRI and if performed before or under treatment. T1 score and percentage of STIR positive muscles (STIR%) were considered and analyzed also in relation to demographic, clinical and laboratory characteristics. RESULTS STIR% was higher in untreated patients and in those who performed MRI earlier (p = 0.001). Pelvic girdle and thighs were in general more affected than legs. T1 score was higher in patients with MRI performed later in disease course (p = 0.004) with a prevalent involvement of the lumbar paraspinal muscles, gluteus medius and minimus, adductor magnus and hamstrings. 22% of STIR positive muscles showed fat replacement progression at second MRI. Higher STIR% at baseline correlated with higher risk of fat replacement at follow-up (p = 0.003); higher T1 score correlated with clinical disability at follow-up, with late treatment start and delayed treatment with IVIG (p = 0.03). INTERPRETATION Muscle MRI is a sensitive biomarker for monitoring disease activity and therapy response, especially when performed early in disease course and before treatment start, and could represent a supportive outcome measure and early prognostic index in IMNM.
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22
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Watanuki K, Koga H. Case report: Diagnostic clues for anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase myopathy in pediatric patients. Front Pediatr 2023; 11:1102539. [PMID: 36994439 PMCID: PMC10040642 DOI: 10.3389/fped.2023.1102539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 02/27/2023] [Indexed: 03/31/2023] Open
Abstract
Introduction Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) myopathy is a recently recognized pathology, but appears less common in children and the characteristics of pediatric cases remain unclear. Case report We report a pediatric case of anti-HMGCR myopathy accompanied by skin rash. Motor function and serum creatine kinase level normalized after combinational treatment including early intravenous immunoglobulin, methotrexate, and corticosteroid. Literature review We searched PubMed and identified reports with detailed clinical information of 33 pediatric patients <18 years old with anti-HMGCR myopathy. Among these 33 patients and our own case, skin rash and maximum serum creatine kinase level >5,000 IU/L were observed in 44% (15 patients) and 94% (32 patients), respectively. Skin rash was present in 15 of the 22 patients (68%) ≥7 years old and none of the 12 patients (0%) <7 years old. Among the 15 patients with skin rash, 12 (80%) presented with erythematous rash. Conclusion Erythematous skin rash may offer a clue to the diagnosis of anti-HMGCR myopathy in children with muscle weakness and serum creatine kinase level >5,000 IU/L in the absence of other myositis-specific antibodies, particularly in patients ≥7 years old. Our results suggest the importance of early anti-HMGCR testing in pediatric patients with these manifestations.
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Affiliation(s)
- Keisuke Watanuki
- Department of Pediatrics, National Hospital Organization Beppu Medical Center, Beppu, Japan
| | - Hiroshi Koga
- Department of Pediatrics, National Hospital Organization Beppu Medical Center, Beppu, Japan
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Sener S, Batu ED, Sari S, Kasap Cuceoglu M, Yildiz AE, Talim B, Aydingoz U, Ozen S, Haliloglu G. A Child with Refractory and Relapsing Anti-3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase Myopathy: Case-Based Review. J Neuromuscul Dis 2023; 10:279-291. [PMID: 36617789 DOI: 10.3233/jnd-221557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND/OBJECTIVE Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (anti-HMGCR) myopathy is rare in children. Here, we present a boy with relapsing refractory anti-HMGCR myopathy along with a systematic literature review. CASE REPORT 17-year-old boy with five years of muscle weakness, rash, high creatinine kinase (CK) levels, and muscle biopsy compatible with inflammatory myopathy was diagnosed with juvenile dermatomyositis. He was treated with corticosteroids, intravenous immunoglobulin (IVIG), and methotrexate. His muscle weakness improved with this treatment although never completely resolved. CK levels decreased from ∼15000 U/L to ∼3000 U/L. At the age of 15, muscle weakness relapsed after an upper respiratory tract infection; pulse corticosteroid treatment was administered. The re-evaluated muscle biopsy showed a necrotizing pattern and the HMGCR antibody was positive confirming anti-HMGCR myopathy when he was 16. The diagnostic delay was 50 months. Disease activity was monitored by Medical Research Council score, MRI and functional tests. Despite corticosteroids, methotrexate, IVIG, cyclosporine A, and rituximab therapies, muscle weakness improved only slightly during the first three months and remained stable afterwards.Results of the Literature Search:We identified 16 articles describing 50 children (76% female) with anti-HMGCR myopathy by reviewing the English literature up to March 1st, 2022. Proximal muscle weakness was the most common clinical symptom (70.8%). Corticosteroids (84.8%), IVIG (58.7%), and methotrexate (56.5%) were preferred in most cases. Complete remission was achieved in nine patients (28.1%). CONCLUSION Diagnosis and management of children with anti-HMGCR myopathy are challenging. Complete remission is achieved in only one third of these patients. Imaging biomarkers may aid treatment.
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Affiliation(s)
- Seher Sener
- Department of Pediatrics, Division of Pediatric Rheumatology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Ezgi Deniz Batu
- Department of Pediatrics, Division of Pediatric Rheumatology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Seher Sari
- Department of Pediatrics, Division of Pediatric Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Muserref Kasap Cuceoglu
- Department of Pediatrics, Division of Pediatric Rheumatology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Adalet Elcin Yildiz
- Department of Radiology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Beril Talim
- Division of Pediatric Pathology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Ustun Aydingoz
- Department of Radiology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Seza Ozen
- Department of Pediatrics, Division of Pediatric Rheumatology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Goknur Haliloglu
- Department of Pediatrics, Division of Pediatric Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey
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24
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Wang CH, Liang WC. Pediatric immune-mediated necrotizing myopathy. Front Neurol 2023; 14:1123380. [PMID: 37021281 PMCID: PMC10067916 DOI: 10.3389/fneur.2023.1123380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/03/2023] [Indexed: 04/07/2023] Open
Abstract
Immune-mediated necrotizing myopathy (IMNM) is a type of inflammatory myopathy. Most patients with IMNM produce anti-3-hydroxy-3-methylglutaryl coenzyme A reductase or anti-signal-recognition particle autoantibodies. IMNM is much rarer in children than in adults. We conducted this mini review focusing on pediatric IMNM to present current evidence regarding its epidemiology, clinical characteristics, diagnosis, and treatment. Our findings indicate that pediatric IMNM often causes severe muscle weakness and is refractory to corticosteroids alone. Furthermore, delayed diagnosis is common because of the clinicopathological similarity between IMNM and inherited myopathy. Raising awareness regarding pediatric IMNM may facilitate early diagnosis and effective treatment.
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Affiliation(s)
- Chen-Hua Wang
- Department of Pediatrics, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wen-Chen Liang
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Pediatrics, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- *Correspondence: Wen-Chen Liang,
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25
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Barp A, Merve A, Shah S, Desikan M, Hanna MG, Bugiardini E. Anti-HMGCR myopathy: barriers to prompt recognition. Pract Neurol 2022; 23:239-242. [PMID: 36564213 DOI: 10.1136/pn-2022-003589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2022] [Indexed: 12/25/2022]
Abstract
Anti-HMGCR (3-hydroxy-3-methylglutaryl coenzyme A reductase) myopathy is an immune-mediated necrotising myopathy. Atypical presentations hinder its recognition and its prompt treatment. We present two patients with atypical clinical or pathological features. A 45-year-old woman had an asymptomatic serum creatine kinase (CK) of ~10 000 IU/L and muscle biopsy showing minimal changes. She then developed slowly progressive proximal weakness, diagnosed as limb-girdle muscular dystrophy but with negative genetics. Twelve years later, now with severe proximal weakness, her MR scan of muscle showed diffuse asymmetrical fatty degeneration, with conspicuous hyperintense STIR signal abnormalities. HMGCR antibodies were positive and she partially improved with immunosuppression. The second patient developed slowly progressive proximal limb weakness with a high serum CK (~4000 IU/L); muscle biopsy showed a lymphocyte infiltrate with angiocentric distribution suggesting vasculitis. Serum HMGCR antibodies were positive. Anti-HMGCR myopathy can present as a slowly progressive myopathy with atypical pathology. HMGCR antibody screening is indicated for people with suspected limb-girdle muscular dystrophy or atypical inflammatory muscle conditions.
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Affiliation(s)
- Andrea Barp
- Centro Clinico NeMO Trento, Ospedale Riabilitativo Villa Rosa, Pergine Valsugana, Italy.,Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Ashirwad Merve
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK.,Department of Neuropathology, National Hospital for Neurology and Neurosurgery, London, UK
| | - Sachit Shah
- Lysholm Department of Neuroradiology, University College London Hospitals NHS Foundation Trust, National Hospital for Neurology and Neurosurgery, London, UK
| | - Mahalekshmi Desikan
- Neuromuscular Complex Care Centre, National Hospital for Neurology and Neurosurgery, London, UK
| | - Michael G Hanna
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
| | - Enrico Bugiardini
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, UK
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26
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Andronie-Cioară FL, Jurcău A, Jurcău MC, Nistor-Cseppentö DC, Simion A. Cholesterol Management in Neurology: Time for Revised Strategies? J Pers Med 2022; 12:jpm12121981. [PMID: 36556202 PMCID: PMC9784893 DOI: 10.3390/jpm12121981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/18/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022] Open
Abstract
Statin therapy has been extensively evaluated and shown to reduce the incidence of new or recurrent vascular events, ischemic stroke included. As a consequence, each published guideline pushes for lower low-density cholesterol levels in the population at large, recommending increased statin doses and/or adding new cholesterol-lowering molecules. Neurologists find it sometimes difficult to apply these guidelines, having to confront situations such as (1) ischemic strokes, mainly cardioembolic ones, in patients with already low LDL-cholesterol levels; (2) myasthenic patients, whose lifespan has been extended by available treatment, and whose age and cholesterol levels put them at risk for ischemic stroke; (3) patients with myotonic dystrophy, whose disease often associates diabetes mellitus and heart conduction defects, and in whom blood cholesterol management is also not settled. As such, further trials are needed to address these issues.
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Affiliation(s)
- Felicia Liana Andronie-Cioară
- Department of Psycho-Neuroscience and Rehabilitation, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania
| | - Anamaria Jurcău
- Department of Psycho-Neuroscience and Rehabilitation, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania
| | - Maria Carolina Jurcău
- Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania
- Correspondence: (M.C.J.); (D.C.N.-C.); Tel.: +40-744-600-833 (M.C.J.)
| | - Delia Carmen Nistor-Cseppentö
- Department of Psycho-Neuroscience and Rehabilitation, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania
- Correspondence: (M.C.J.); (D.C.N.-C.); Tel.: +40-744-600-833 (M.C.J.)
| | - Aurel Simion
- Department of Psycho-Neuroscience and Rehabilitation, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania
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27
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White Z, Sun Z, Sauge E, Cox D, Donen G, Pechkovsky D, Straub V, Francis GA, Bernatchez P. Limb-girdle muscular dystrophy type 2B causes HDL-C abnormalities in patients and statin-resistant muscle wasting in dysferlin-deficient mice. Skelet Muscle 2022; 12:25. [PMID: 36447272 PMCID: PMC9706908 DOI: 10.1186/s13395-022-00308-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/11/2022] [Indexed: 12/03/2022] Open
Abstract
Limb-girdle muscular dystrophy (MD) type 2B (LGMD2B) and Duchenne MD (DMD) are caused by mutations to the Dysferlin and Dystrophin genes, respectively. We have recently demonstrated in typically mild dysferlin- and dystrophin-deficient mouse models that increased plasma cholesterol levels severely exacerbate muscle wasting, and that DMD patients display primary dyslipidemia characterized by elevated plasma cholesterol and triglycerides. Herein, we investigate lipoprotein abnormalities in LGMD2B and if statin therapy protects dysferlin-deficient mice (Dysf) from muscle damage. Herein, lipoproteins and liver enzymes from LGMD2B patients and dysferlin-null (Dysf) mice were analyzed. Simvastatin, which exhibits anti-muscle wasting effects in mouse models of DMD and corrects aberrant expression of key markers of lipid metabolism and endogenous cholesterol synthesis, was tested in Dysf mice. Muscle damage and fibrosis were assessed by immunohistochemistry and cholesterol signalling pathways via Western blot. LGMD2B patients show reduced serum high-density lipoprotein cholesterol (HDL-C) levels compared to healthy controls and exhibit a greater prevalence of abnormal total cholesterol (CHOL)/HDL-C ratios despite an absence of liver dysfunction. While Dysf mice presented with reduced CHOL and associated HDL-C and LDL-C-associated fractions, simvastatin treatment did not prevent muscle wasting in quadriceps and triceps muscle groups or correct aberrant low-density lipoprotein receptor (LDLR) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) protein expression. LGMD2B patients present with reduced serum concentrations of HDL-C, a major metabolic comorbidity, and as a result, statin therapy is unlikely to prevent muscle wasting in this population. We propose that like DMD, LGMD2B should be considered as a new type of genetic dyslipidemia.
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Affiliation(s)
- Zoe White
- grid.17091.3e0000 0001 2288 9830Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia (UBC), 217-2176 Health Sciences Mall, Vancouver, BC V6T 1Z3 Canada ,grid.416553.00000 0000 8589 2327UBC Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, Canada
| | - Zeren Sun
- grid.17091.3e0000 0001 2288 9830Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia (UBC), 217-2176 Health Sciences Mall, Vancouver, BC V6T 1Z3 Canada ,grid.416553.00000 0000 8589 2327UBC Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, Canada
| | - Elodie Sauge
- grid.17091.3e0000 0001 2288 9830Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia (UBC), 217-2176 Health Sciences Mall, Vancouver, BC V6T 1Z3 Canada ,grid.416553.00000 0000 8589 2327UBC Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, Canada
| | - Dan Cox
- grid.1006.70000 0001 0462 7212Newcastle University Translational and Clinical Research Institute, Newcastle upon Tyne, UK
| | - Graham Donen
- grid.17091.3e0000 0001 2288 9830Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia (UBC), 217-2176 Health Sciences Mall, Vancouver, BC V6T 1Z3 Canada ,grid.416553.00000 0000 8589 2327UBC Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, Canada
| | - Dmitri Pechkovsky
- grid.17091.3e0000 0001 2288 9830Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia (UBC), 217-2176 Health Sciences Mall, Vancouver, BC V6T 1Z3 Canada ,grid.416553.00000 0000 8589 2327UBC Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, Canada
| | - Volker Straub
- grid.1006.70000 0001 0462 7212Newcastle University Translational and Clinical Research Institute, Newcastle upon Tyne, UK
| | - Gordon A. Francis
- grid.416553.00000 0000 8589 2327UBC Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, Canada ,grid.17091.3e0000 0001 2288 9830Department of Medicine, UBC, Vancouver, Canada
| | - Pascal Bernatchez
- grid.17091.3e0000 0001 2288 9830Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia (UBC), 217-2176 Health Sciences Mall, Vancouver, BC V6T 1Z3 Canada ,grid.416553.00000 0000 8589 2327UBC Centre for Heart Lung Innovation, St. Paul’s Hospital, Vancouver, Canada
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28
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Yang MG, Zhang Q, Wang H, Ma X, Ji S, Li Y, Xu L, Bi Z, Bu B. The accumulation of muscle RING finger-1 in regenerating myofibers: Implications for muscle repair in immune-mediated necrotizing myopathy. Front Neurol 2022; 13:1032738. [PMID: 36504647 PMCID: PMC9730696 DOI: 10.3389/fneur.2022.1032738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/07/2022] [Indexed: 11/26/2022] Open
Abstract
Background Muscle RING finger-1 (MuRF-1) plays a key role in the degradation of skeletal muscle proteins. We hypothesize the involvement of MuRF-1 in immune-mediated necrotizing myopathy (IMNM). Methods Muscle biopsies from patients with IMNM (n = 37) were analyzed and compared to biopsies from patients with dermatomyositis (DM, n = 13), dysferlinopathy (n = 9) and controls (n = 7) using immunostaining. Results MuRF-1 staining could be observed in IMNM, DM and dysferlinopathy biopsies, whereas the percentage of MuRF-1 positive myofibers was significantly higher in IMNM than in dysferlinopathy (p = 0.0448), and positively correlated with muscle weakness and disease activity in IMNM and DM. Surprisingly, MuRF-1 staining predominantly presented in regenerating fibers but not in atrophic fibers. Moreover, MuRF-1-positive fibers tended to be distributed around necrotic myofibers and myofibers with sarcolemma membrane attack complex deposition. Abundant MuRF-1 expression in IMNM and DM was associated with rapid activation of myogenesis after muscle injury, whereas relatively low expression of MuRF-1 in dysferlinopathy may be attributed to damaged muscle regeneration. Conclusions MuRF-1 accumulated in regenerating myofibers, which may contribute to muscle injury repair in IMNM and DM. MuRF-1 staining may help clinicians differentiate IMNM and dysferlinopathy.
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Affiliation(s)
- Meng-Ge Yang
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qing Zhang
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hong Wang
- Genetic Diagnostic Centre, Department of Internal Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xue Ma
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Suqiong Ji
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yue Li
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Li Xu
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhuajin Bi
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bitao Bu
- Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China,*Correspondence: Bitao Bu
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The Clinicopathological Distinction between Immune-Mediated Necrotizing Myopathy and Limb-Girdle Muscular Dystrophy R2: Key Points to Prevent Misdiagnosis. J Clin Med 2022; 11:jcm11216566. [PMID: 36362794 PMCID: PMC9655252 DOI: 10.3390/jcm11216566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/30/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
Background: Limb−girdle muscular dystrophy R2 (LGMD R2) is most frequently misdiagnosed as immune-mediated necrotizing myopathy (IMNM). This study aimed to compare the clinicopathological data of IMNM and LGMD R2 to find distinguishing features. Methods: We retrospectively reassessed the medical data of patients with IMNM (n = 41) and LGMD R2 (n = 8) treated at Tongji Hospital from January 2017 to December 2021. Results: In our cohort, patients with LGMD R2 had a longer interval of onset to first visit, mild muscle weakness with late upper limb involvement, less myalgia, no cervical muscle weakness or dysphagia, no extramuscular organs affected except cardiac involvement, and lack of various autoantibodies, such as antinuclear antibodies. These features were completely reversed in IMNM. Moreover, thigh MRIs showed that muscle edema prominently affecting the adductor magnus was a characteristic of IMNM, while extensive fatty replacement was more common in LGMD R2 (p = 0.0086). Necrotic myofibers presented in both entities (p = 0.1693), while features such as ring/whorled and splitting myofibers were more often found in LGMD R2 (p = 0.0112 and p < 0.0001, respectively). Conversely, sarcoplasmic p62 expression was more pronounced in IMNM (p < 0.05). There were 4 of 8 (50%) patients with LGMD R2 initially considered as seronegative IMNM, and therefore unnecessarily treated with immunosuppressive drugs. Insufficient recognition of the early clinical, imaging, and histopathological features of LGMD R2 is the main reason for misdiagnosis. Conclusions: These findings may help clinicians differentiate seronegative IMNM and LGMD R2, reducing early misdiagnosis and mismanagement. Particularly, prominent adductor magnus edema on MRI and abundant p62 staining seem to be good markers for IMNM, while the presence of splitting myofibers is a crucial clue to early hereditary myopathy, including LGMD R2.
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Ma X, Bu BT. Anti-SRP immune-mediated necrotizing myopathy: A critical review of current concepts. Front Immunol 2022; 13:1019972. [PMID: 36311711 PMCID: PMC9612835 DOI: 10.3389/fimmu.2022.1019972] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/12/2022] [Indexed: 11/18/2022] Open
Abstract
Purpose of review This review aims to describe clinical and histological features, treatment, and prognosis in patients with anti-signal recognition particle (SRP) autoantibodies positive immune-mediated necrotizing myopathy (SRP-IMNM) based on previous findings. Previous findings Anti-SRP autoantibodies are specific in IMNM. Humoral autoimmune and inflammatory responses are the main autoimmune characteristics of SRP-IMNM. SRP-IMNM is clinically characterized by acute or subacute, moderately severe, symmetrical proximal weakness. Younger patients with SRP-IMNM tend to have more severe clinical symptoms. Patients with SRP-IMNM may be vulnerable to cardiac involvement, which ought to be regularly monitored and cardiac magnetic resonance imaging is the recommended detection method. The pathological features of SRP-IMNM are patchy or diffuse myonecrosis and myoregeneration accompanied by a paucity of inflammatory infiltrates. Endoplasmic reticulum stress-induced autophagy pathway and necroptosis are activated in skeletal muscle of SRP-IMNM. Treatment of refractory SRP-IMNM encounters resistance and warrants further investigation. Summary Anti-SRP autoantibodies define a unique population of IMNM patients. The immune and non-immune pathophysiological mechanisms are involved in SRP-IMNM.
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Affiliation(s)
- Xue Ma
- Department of Neurology, Tangdu Hospital, Air Force Medical University, Xi’an, China
| | - Bi-Tao Bu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- *Correspondence: Bi-Tao Bu,
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Ng KWP, Chin HL, Chin AXY, Goh DLM. Using gene panels in the diagnosis of neuromuscular disorders: A mini-review. Front Neurol 2022; 13:997551. [PMID: 36313509 PMCID: PMC9602396 DOI: 10.3389/fneur.2022.997551] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/21/2022] [Indexed: 09/26/2023] Open
Abstract
The diagnosis of inherited neuromuscular disorders is challenging due to their genetic and phenotypic variability. Traditionally, neurophysiology and histopathology were primarily used in the initial diagnostic approach to these conditions. Sanger sequencing for molecular diagnosis was less frequently utilized as its application was a time-consuming and cost-intensive process. The advent and accessibility of next-generation sequencing (NGS) has revolutionized the evaluation process of genetically heterogenous neuromuscular disorders. Current NGS diagnostic testing approaches include gene panels, whole exome sequencing (WES), and whole genome sequencing (WGS). Gene panels are often the most widely used, being more accessible due to availability and affordability. In this mini-review, we describe the benefits and risks of clinical genetic testing. We also discuss the utility, benefits, challenges, and limitations of using gene panels in the evaluation of neuromuscular disorders.
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Affiliation(s)
- Kay W. P. Ng
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
| | - Hui-Lin Chin
- Division of Genetics and Metabolism, Department of Paediatrics, Khoo Teck Puat - National University Children's Medical Institute, National University Hospital, Singapore, Singapore
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Amanda X. Y. Chin
- Division of Neurology, Department of Medicine, National University Hospital, Singapore, Singapore
| | - Denise Li-Meng Goh
- Division of Genetics and Metabolism, Department of Paediatrics, Khoo Teck Puat - National University Children's Medical Institute, National University Hospital, Singapore, Singapore
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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32
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Munekane A, Ohsawa Y, Okubo M, Nagai T, Nishimura H, Nishino I, Sunada Y. Becker Muscular Dystrophy Accompanied by Anti-HMGCR Antibody-positive Immune-mediated Necrotizing Myopathy. Intern Med 2022; 62:1345-1349. [PMID: 36130887 DOI: 10.2169/internalmedicine.0202-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Becker muscular dystrophy (BMD) is an X-linked neuromuscular disease characterized by progressive muscle weakness that currently has no cure. Immune-mediated necrotizing myopathy (IMNM) is a type of autoimmune inflammatory myopathy characterized by proximal muscle weakness that is treated with immunosuppressive therapy. We herein report a patient diagnosed with BMD complicated with IMNM by a pathological analysis. Notably, the patient had an elevated serum anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody level. Oral glucocorticoid and methotrexate treatment partially improved the muscle weakness with decreased levels of serum creatine kinase. An accurate diagnosis is important for therapeutic decisions in these complicated cases.
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Affiliation(s)
| | - Yutaka Ohsawa
- Department of Neurology, Kawasaki Medical School, Japan
| | - Mariko Okubo
- Department of Neuromuscular Research, National Institute of Neuroscience (NCNP), Japan
| | - Taiji Nagai
- Department of Neurology, Kawasaki Medical School, Japan
| | | | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience (NCNP), Japan
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Damoiseaux J, Mammen AL, Piette Y, Benveniste O, Allenbach Y. 256 th ENMC international workshop: Myositis specific and associated autoantibodies (MSA-ab): Amsterdam, The Netherlands, 8-10 October 2021. Neuromuscul Disord 2022; 32:594-608. [PMID: 35644723 DOI: 10.1016/j.nmd.2022.05.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 10/18/2022]
Affiliation(s)
- Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, the Netherlands.
| | - Andrew L Mammen
- Muscle Disease Unit. Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, United States
| | - Yves Piette
- Department of Rheumatology, Ghent University Hospital, Ghent, Belgium; Department of Internal Medicine, Ghent University, Ghent, Belgium
| | - Olivier Benveniste
- Department of Internal Medicine and Clinical Immunology, Sorbonne Université, INSERM, UMR974, Pitié-Salpêtrière University Hospital, Paris, France
| | - Yves Allenbach
- Department of Internal Medicine and Clinical Immunology, Sorbonne Université, INSERM, UMR974, Pitié-Salpêtrière University Hospital, Paris, France
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Hiebeler M, Franke R, Ingenerf M, Krause S, Mohassel P, Pak K, Mammen A, Schoser B, Bönnemann CG, Walter MC. Slowly Progressive Limb-Girdle Weakness and HyperCKemia - Limb Girdle Muscular Dystrophy or Anti-3-Hydroxy-3-Methylglutaryl-CoA-Reductase-Myopathy? J Neuromuscul Dis 2022; 9:607-614. [PMID: 35754285 DOI: 10.3233/jnd-220810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Anti-3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR)-myopathy is a usually rapidly progressive form of immune-mediated necrotizing myopathy (IMNM). Rarer clinical courses show slow progression and resemble the phenotype of limb-girdle dystrophy (LGMD). OBJECTIVE We demonstrate the difficulties in differentiating LGMD versus anti-HMGCR-myopathy. METHODS We report on a 48-year-old patient with slowly progressive tetraparesis and hyperCKemia for more than 20 years. RESULTS Due to myopathic changes in initial and second muscle biopsy and typical clinical presentation, the patient was diagnosed with LGMD 20 years ago; despite comprehensive genetic testing including exome diagnostics, the genetic cause of disease could not be identified. Finally, HMG-CoA reductase antibodies were detected, confirming the diagnosis of anti-HMGCR-myopathy. By re-work-up of a second muscle biopsy specimen from year 2009, the diagnosis of a IMNM was made in retrospect. Seven cycles of high-dose immunoglobulins were administered; patient reported outcome measures have mildly improved. CONCLUSION Patients with clinical LGMD phenotype, degenerative changes in muscle biopsy but without genetic confirmation of the disease should be tested for HMG-CoA-myopathy, thereby allowing for an early start of treatment.
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Affiliation(s)
- Miriam Hiebeler
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Raimo Franke
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Maria Ingenerf
- Department of Radiology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Sabine Krause
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Payam Mohassel
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Katherine Pak
- Muscle Disease Unit, Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Andrew Mammen
- Muscle Disease Unit, Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Benedikt Schoser
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Carsten G Bönnemann
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Maggie C Walter
- Friedrich-Baur-Institute, Department of Neurology, Ludwig-Maximilians-University of Munich, Munich, Germany
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Cerino M, González-Hormazábal P, Abaji M, Courrier S, Puppo F, Mathieu Y, Trangulao A, Earle N, Castiglioni C, Díaz J, Campero M, Hughes R, Vargas C, Cortés R, Kleinsteuber K, Acosta I, Urtizberea JA, Lévy N, Bartoli M, Krahn M, Jara L, Caviedes P, Gorokhova S, Bevilacqua JA. Genetic Profile of Patients with Limb-Girdle Muscle Weakness in the Chilean Population. Genes (Basel) 2022; 13:genes13061076. [PMID: 35741838 PMCID: PMC9223019 DOI: 10.3390/genes13061076] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/04/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022] Open
Abstract
Hereditary myopathies are a group of genetically determined muscle disorders comprising more than 300 entities. In Chile, there are no specific registries of the distinct forms of these myopathies. We now report the genetic findings of a series of Chilean patients presenting with limb-girdle muscle weakness of unknown etiology. Eighty-two patients were explored using high-throughput sequencing approaches with neuromuscular gene panels, establishing a definite genetic diagnosis in 49 patients (59.8%) and a highly probable genetic diagnosis in eight additional cases (9.8%). The most frequent causative genes identified were DYSF and CAPN3, accounting for 22% and 8.5% of the cases, respectively, followed by DMD (4.9%) and RYR1 (4.9%). The remaining 17 causative genes were present in one or two cases only. Twelve novel variants were identified. Five patients (6.1%) carried a variant of uncertain significance in genes partially matching the clinical phenotype. Twenty patients (24.4%) did not carry a pathogenic or likely pathogenic variant in the phenotypically related genes, including five patients (6.1%) presenting an autoimmune neuromuscular disorder. The relative frequency of the different forms of myopathy in Chile is like that of other series reported from different regions of the world with perhaps a relatively higher incidence of dysferlinopathy.
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Affiliation(s)
- Mathieu Cerino
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
| | - Patricio González-Hormazábal
- Programa de Genética Humana, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 8380492, Chile; (P.G.-H.); (A.T.); (L.J.)
| | - Mario Abaji
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
| | - Sebastien Courrier
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
| | - Francesca Puppo
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
| | - Yves Mathieu
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
| | - Alejandra Trangulao
- Programa de Genética Humana, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 8380492, Chile; (P.G.-H.); (A.T.); (L.J.)
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago 8380492, Chile; (M.C.); (R.H.)
- Unidad de Patología Neuromuscular, Departamento de Neurología y Neurocirugía, Clínica Dávila, Santiago 8431657, Chile; (N.E.); (I.A.)
- Departamento de Anatomía y Medicina Legal, Facultad de Medicina, Universidad de Chile, Santiago 8380456, Chile
| | - Nicholas Earle
- Unidad de Patología Neuromuscular, Departamento de Neurología y Neurocirugía, Clínica Dávila, Santiago 8431657, Chile; (N.E.); (I.A.)
| | - Claudia Castiglioni
- Unidad de Neurología, Departamento de Pediatría, Clínica Las Condes, Santiago 7591047, Chile; (C.C.); (R.C.); (K.K.)
| | - Jorge Díaz
- Centro de Imagenología, Hospital Clínico Universidad de Chile, Santiago 8380492, Chile;
| | - Mario Campero
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago 8380492, Chile; (M.C.); (R.H.)
| | - Ricardo Hughes
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago 8380492, Chile; (M.C.); (R.H.)
| | - Carmen Vargas
- Neurología Pediátrica Hospital Roberto del Río, Universidad de Chile, Santiago 8380492, Chile;
| | - Rocío Cortés
- Unidad de Neurología, Departamento de Pediatría, Clínica Las Condes, Santiago 7591047, Chile; (C.C.); (R.C.); (K.K.)
- Neurología Pediátrica Hospital Roberto del Río, Universidad de Chile, Santiago 8380492, Chile;
| | - Karin Kleinsteuber
- Unidad de Neurología, Departamento de Pediatría, Clínica Las Condes, Santiago 7591047, Chile; (C.C.); (R.C.); (K.K.)
- Neurología Pediátrica Hospital Roberto del Río, Universidad de Chile, Santiago 8380492, Chile;
| | - Ignacio Acosta
- Unidad de Patología Neuromuscular, Departamento de Neurología y Neurocirugía, Clínica Dávila, Santiago 8431657, Chile; (N.E.); (I.A.)
| | | | - Nicolas Lévy
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
- Department of Medical Genetics, Hôpital Timone Enfants, APHM, 13385 Marseille, France
| | - Marc Bartoli
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
| | - Martin Krahn
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
- Department of Medical Genetics, Hôpital Timone Enfants, APHM, 13385 Marseille, France
| | - Lilian Jara
- Programa de Genética Humana, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago 8380492, Chile; (P.G.-H.); (A.T.); (L.J.)
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago 8380492, Chile;
- Centro de Biotecnología y Bioingeniería (CeBiB), Departamento de Ingeniería Química, Biotecnología y Biomateriales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago 8380492, Chile
| | - Svetlana Gorokhova
- Marseille Medical Genetics Université, INSERM, U 1251, Aix-Marseille Université, 13005 Marseille, France; (M.C.); (M.A.); (S.C.); (F.P.); (Y.M.); (N.L.); (M.B.); (M.K.); (S.G.)
- Department of Medical Genetics, Hôpital Timone Enfants, APHM, 13385 Marseille, France
| | - Jorge A. Bevilacqua
- Unidad Neuromuscular, Departamento Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Santiago 8380492, Chile; (M.C.); (R.H.)
- Unidad de Patología Neuromuscular, Departamento de Neurología y Neurocirugía, Clínica Dávila, Santiago 8431657, Chile; (N.E.); (I.A.)
- Departamento de Anatomía y Medicina Legal, Facultad de Medicina, Universidad de Chile, Santiago 8380456, Chile
- Correspondence:
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Nicolau S, Milone M, Liewluck T. Reply to: Atypical presentations of immune-mediated necrotizing myopathy: Clues and caveats. Muscle Nerve 2022; 65:E30-E31. [PMID: 35373841 DOI: 10.1002/mus.27549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 02/23/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Stefan Nicolau
- Department of Neurology, Mayo Clinic, Rochester, Minnesota.,Center for Gene Therapy, Abigail Wexner Research institute, Nationwide Children's Hospital, Columbus, Ohio
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Yang H, Tian X, Zhang L, Li W, Liu Q, Jiang W, Peng Q, Wang G, Lu X. Clinical and pathological features of immune-mediated necrotising myopathies in a single-centre muscle biopsy cohort. BMC Musculoskelet Disord 2022; 23:425. [PMID: 35524238 PMCID: PMC9074315 DOI: 10.1186/s12891-022-05372-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 04/25/2022] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE Immune-mediated necrotising myopathy (IMNM) is a subset of idiopathic inflammatory myopathies (IIM) characterized by significantly elevated creatine kinase level, muscle weakness and predominant muscle fibre necrosis in muscle biopsy. This study aimed to investigate the clinical and pathological characteristics of patients with IMNM in a single-centre muscle biopsy cohort. METHODS A total of 860 patients who had muscle biopsy reports in our centre from May 2008 to December 2017 were enrolled in this study. IMNM was diagnosed according to the 2018 European Neuromuscular Centre (ENMC) clinicopathological diagnostic criteria for IMNM. RESULTS The muscle biopsy cohort consisted of 531 patients with IIM (61.7%), 253 patients with non-IIM (29.4%), and 76 undiagnosed patients (8.8%). IIM cases were classified as IMNM (68[7.9%]), dermatomyositis (346[40.2%]), anti-synthetase syndrome (82[9.5%]), polymyositis (32[3.7%]), and sporadic inclusion body myositis (3[0.3%]). Limb girdle muscular dystrophy (LGMD) 2B and lipid storage myopathy (LSM) are the two most common non-IIM disorders in our muscle biopsy cohort. IMNM patients had a higher onset age (41.57 ± 14.45 vs 21.66 ± 7.86 and 24.56 ± 10.78, p < .0001), shorter duration (21.79 ± 26.01 vs 66.69 ± 67.67 and 24.56 ± 10.78, p < .0001), and more frequent dysphagia (35.3% vs. 3.4 and 6.3%, p = .001) than LGMD 2B and LSM patients. Muscle biopsy from IMNM showed more frequent muscle fibre necrosis (95.6% vs 72.4 and 56.3%, p < .0001), overexpression of major histocompatibility complex-I on sarcolemma (83.8% vs 37.9 and 12.9%, p < .0001), and CD4+ T cell endomysia infiltration (89.7% vs 53.6 and 50%, p < .0001) compared with those from LGMD 2B and LSM patients. CONCLUSIONS It is easy to distinguish IMNM from other IIM subtypes according to clinical symptoms and myositis specific antibodies profiles. However, distinguishing IMNM from disorders clinically similar to non-IIM needs combined clinical, serological and pathological features.
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Affiliation(s)
- Hongxia Yang
- China-Japan Friendship School of Clinical Medicine, Peking University, Beijing, 100029, China
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China
| | - Xiaolan Tian
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China
| | - Lining Zhang
- China-Japan Friendship School of Clinical Medicine, Peking University, Beijing, 100029, China
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China
| | - Wenli Li
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China
| | - Qingyan Liu
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China
| | - Wei Jiang
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China
| | - Qinglin Peng
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China
| | - Guochun Wang
- China-Japan Friendship School of Clinical Medicine, Peking University, Beijing, 100029, China.
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China.
| | - Xin Lu
- China-Japan Friendship School of Clinical Medicine, Peking University, Beijing, 100029, China.
- Department of Rheumatology, China-Japan Friendship Hospital, Yinghua East Road, Chaoyang District, Beijing, 100029, China.
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The prevalence and clinical characteristics of anti-HMGCR (anti-3-hydroxy-3-methyl-glutaryl-coenzyme A reductase) antibodies in idiopathic inflammatory myopathy: an analysis from the MyoCite registry. Rheumatol Int 2022; 42:1143-1154. [PMID: 35031847 DOI: 10.1007/s00296-021-05063-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/30/2021] [Indexed: 10/19/2022]
Abstract
This study aimed to determine the prevalence and clinical characteristics of anti-HMGCR antibodies in idiopathic inflammatory myositis (IIM) at a tertiary care centre in northern India. Data (adult and children) were retrieved from the MyoCite dataset, identifying patients with polymyositis, dermatomyositis, and antibody-negative IIM whilst fulfilling the ACR/EULAR criteria. SLE, sarcoidosis, and systemic sclerosis were included for comparison as disease controls. The baseline clinical profile, laboratory tests, and muscle biopsies were retrieved and analysed. Descriptive statistics and non-parametric statistics were used for comparison. Among 128 IIM (112 adults, 16 children, M:F 1:2.8) of age 37 (24-47) years and 6 (3-17) months disease duration, 4 (3.6%) young adults tested positive for anti-HMGCR antibodies. All children and disease control tested negative for the antibody. Anti-HMGCR + IIM exhibited higher muscle enzymes [AST (367 vs 104 IU/L, p = 0.045), ALT (502 vs 78 IU/L, p = 0.004), and CPK (12,242 vs 699 IU/L, p = 0.001] except lactate dehydrogenase with less frequent systemic features such as fatigue than antibody-negative IIM. One young girl presented with a Limb-girdle muscular dystrophy (LGMD) with chronic pattern. None of the patients exhibited rashes, statin exposure, or cancer, though one had anti-Ro52 and mild disease. Our observations depict a younger population while affirming previous literature, including NM-like presentation, and chronic LGMD-like pattern of weakness in one case. Although a small number of children were included, ours is one of the few paediatric studies that evaluated HMGCR antibodies thus far. Further investigations in a larger Indian cohort are warranted to substantiate our findings.
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Merlonghi G, Antonini G, Garibaldi M. Immune-mediated necrotizing myopathy (IMNM): A myopathological challenge. Autoimmun Rev 2021; 21:102993. [PMID: 34798316 DOI: 10.1016/j.autrev.2021.102993] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/14/2021] [Indexed: 02/07/2023]
Abstract
This review is focused on the myopathological spectrum of immune mediated necrotizing myopathies (IMNMs) and its differentiation with other, potentially mimicking, inflammatory and non-inflammatory myopathies. IMNMs are a subgroup of idiopathic inflammatory myopathies (IIMs) characterized by severe clinical presentation with rapidly progressive muscular weakness and creatine kinase elevation, often requiring early aggressive immunotherapy, associated to the presence of muscle specific autoantibodies (MSA) against signal recognition particle (SRP) or 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR). Muscle biopsy usually shows unspecific features consisting in prominent necrosis and regeneration of muscle fibres with mild or absent inflammatory infiltrates, inconstant and faint expression of major histocompatibility complex (MHC) class I and variable deposition of C5b-9 on sarcolemma. Several conditions could present similar histopathological findings leading to possible misdiagnosis of IMNM with other IIMs or non-inflammatory myopathies (nIMs) and viceversa. This review analyses the muscle biopsy data in IMNMs through a systematic revision of the literature from the last five decades. Several histopathological variables have been considered in both SRP- and HMGCR-IMNM, and compared to other IIMs - as dermatomyositis (DM) and anti-synthethase syndrome (ASS) - or other nIMs -as toxic myopathies (TM), critical illness myopathy (CIM) and muscular dystrophy (MD) - to elucidate similarities and differences among these potentially mimicking conditions. The major histopathological findings of IMNMs were: very frequent necrosis and regeneration of muscle fibres (93%), mild inflammatory component mainly constituted by scattered isolated (65%) CD68-prevalent (68%) cells, without CD8 invading/surrounding non-necrotic fibres, variable expression of MHC-I in non-necrotic fibres (56%) and constant expression of sarcoplasmic p62, confirming those that are widely considered the major histological characteristics of IMNMs. Conversely, only 42% of biopsies showed a sarcolemmal deposition of C5b-9 component. Few differences between SRP and HMGCR IMNMs consisted in more severe necrosis and regeneration in SRP than in HMGCR (p = 0.01); more frequent inflammatory infiltrates (p = 0.007) with perivascular localization (p = 0.01) and clustered expression of MHC-I (p = 0.007) in HMGCR; very low expression of sarcolemmal C5b-9 in SRP (18%) compared to HMGCR (56%) (p = 0.0001). Milder necrosis and regeneration, detection of perifascicular pathology, presence of lymphocytic inflammatory infiltrates and myofibre expression of MxA help to distinguish DM or ASS from IMNM. nIMs can present signs of inflammation at muscle biopsy. Low fibre size variability with overexpression of both MHC-I and II, associated with C5b-9 deposition, could could be observed in CIM, while increased connective tissue should lead to consider MD, or TM in absence of C5b-9 deposition. Nevertheless, these features are not constantly detected and muscle biopsy could not be diriment. For this reason, muscle biopsy should always be critically considered in light of the clinical context before concluding for a definite diagnosis of IMNM, only based on histopathological findings. More rigorous collection and analysis of muscle biopsy is warranted to obtain a higher quality and more homogeneous histopathological data in inflammatory myopathies.
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Affiliation(s)
- Gioia Merlonghi
- Neuromuscular and Rare Disease Centre, Department of Neuroscience, Mental Health and Sensory Organs (NESMOS), SAPIENZA University of Rome, Sant'Andrea Hospital, Rome, Italy
| | - Giovanni Antonini
- Neuromuscular and Rare Disease Centre, Department of Neuroscience, Mental Health and Sensory Organs (NESMOS), SAPIENZA University of Rome, Sant'Andrea Hospital, Rome, Italy
| | - Matteo Garibaldi
- Neuromuscular and Rare Disease Centre, Department of Neuroscience, Mental Health and Sensory Organs (NESMOS), SAPIENZA University of Rome, Sant'Andrea Hospital, Rome, Italy.
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Abstract
PURPOSE OF REVIEW Necrotizing myopathy is a broad term. It includes patients with the recently described immune-mediated necrotizing myopathies (IMNM) who have specific antibodies, such as anti-hydroxy-3-methylglutaryl-CoA reductase or anti-signal recognition particle, seronegative phenotypes that can be associated with cancer, and other types of myositis and connective tissue diseases involving necrotic muscle fibers as a characteristic pathologic feature. Necrotizing myopathies that are not immune-mediated, such as those caused by drugs, dystrophies, infections, or even hypothyroidism are also included. The purpose of this review is to address the differential diagnosis of these disorders. RECENT FINDINGS New IMNM have been described over the last few years, some of them related with checkpoint inhibitors, drugs that are being increasingly used in cancer treatment. Necrotizing myopathy has also been reported in association with specific phenotypes and autoantibodies (e.g. anti-Mi2 dermatomyositis, antisynthetase syndrome, and myositis associated with antimitochondrial antibodies). Rarer cases associated with graft-versus-host disease and severe acute respiratory syndrome coronavirus 2 infection are also emerging. SUMMARY Differentiation between patients with IMNM and those without the superimposed autoimmune phenomena helps clinicians determine the best individualized approach to use and the appropriate immunosuppressive therapy, whenever needed.
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Abstract
PURPOSE OF REVIEW This review aims to describe clinical and pathological features, prognosis and treatment in patients with anti-HMGCR antibody positive immune-mediated necrotizing myopathy (HMGCR-IMNM) based on recent findings. RECENT FINDINGS Using advances in diagnostic modalities that can confirm the presence of anti-HMGCR antibody, the clinical and pathological manifestations of HMGCR-IMNM were found to be broader than previously reported. Although only a small percentage of HMGCR-IMNM patients present with atypical manifestations, some of these patients show slow disease progression and clinical symptoms, which are similar to those of limb-girdle muscular dystrophies. Other atypical HMGCR-IMNM patients have skin conditions similar to dermatomyositis-like skin rush or dermatological presentations of Jessner-Kanoff disease or cutaneous lymphoma, whose pathological changes including CD8-positive and bcl-2-positive lymphocytic accumulations, similar to Jessner-Kanoff lymphocytic infiltration of skin or low-grade cutaneous lymphoma, which are observed in muscle and skin. SUMMARY Anti-HMGCR autoantibodies define unique populations of IMNM patients. Recent studies have revealed that clinicopathological manifestations of HMGCR-IMNM, especially extramuscular symptoms and pathological manifestations, are more common than previously recognized.
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Gemelli C, Traverso M, Trevisan L, Fabbri S, Scarsi E, Carlini B, Prada V, Mongini T, Ruggiero L, Patrone S, Gallone S, Iodice R, Pisciotta L, Zara F, Origone P, Rota E, Minetti C, Bruno C, Schenone A, Mandich P, Fiorillo C, Grandis M. An integrated approach to the evaluation of patients with asymptomatic or minimally symptomatic hyperCKemia. Muscle Nerve 2021; 65:96-104. [PMID: 34687219 PMCID: PMC9298868 DOI: 10.1002/mus.27448] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 10/17/2021] [Accepted: 10/18/2021] [Indexed: 02/01/2023]
Abstract
Introduction/Aims Currently, there are no straightforward guidelines for the clinical and diagnostic management of hyperCKemia, a frequent and nonspecific presentation in muscle diseases. Therefore, we aimed to describe our diagnostic workflow for evaluating patients with this condition. Methods We selected 83 asymptomatic or minimally symptomatic patients with persistent hyperCKemia for participation in this Italian multicenter study. Patients with facial involvement and distal or congenital myopathies were excluded, as were patients with suspected inflammatory myopathies or predominant respiratory or cardiac involvement. All patients underwent a neurological examination and nerve conduction and electromyography studies. The first step of the investigation included a screening for Pompe disease. We then evaluated the patients for myotonic dystrophy type II–related CCTG expansion and excluded patients with copy number variations in the DMD gene. Subsequently, the undiagnosed patients were investigated using a target gene panel that included 20 genes associated with isolated hyperCKemia. Results Using this approach, we established a definitive diagnosis in one third of the patients. The detection rate was higher in patients with severe hyperCKemia and abnormal electromyographic findings. Discussion We have described our diagnostic workflow for isolated hyperCKemia, which is based on electrodiagnostic data, biochemical screening, and first‐line genetic investigations, followed by successive targeted sequencing panels. Both clinical signs and electromyographic abnormalities are associated with increased diagnostic yields.
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Affiliation(s)
- Chiara Gemelli
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Genoa, Italy
| | - Monica Traverso
- Paediatric Neurology and Muscular Diseases Unit, IRCCS G. Gaslini Institute, Genoa, Italy
| | - Lucia Trevisan
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Genoa, Italy
| | - Sabrina Fabbri
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Genoa, Italy
| | - Elena Scarsi
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Genoa, Italy
| | - Barbara Carlini
- Unit of Medical Genetics, IRCCS G. Gaslini Institute, Genoa, Italy
| | - Valeria Prada
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Genoa, Italy
| | - Tiziana Mongini
- Neuromuscular Unit, Department of Neurosciences Rita Levi Montalcini, University of Torino, Torino, Italy
| | - Lucia Ruggiero
- Dipartimento di Neuroscienze e Scienze Riproduttive ed Odontostomatologiche, Università degli Studi di Napoli "Federico II,", Naples, Italy
| | - Serena Patrone
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Genoa, Italy
| | - Salvatore Gallone
- Neurogenetic Service, Department of Neurosciences, AOU Città della salute e della scienza, Torino, Italy
| | - Rosa Iodice
- Dipartimento di Neuroscienze e Scienze Riproduttive ed Odontostomatologiche, Università degli Studi di Napoli "Federico II,", Naples, Italy
| | - Livia Pisciotta
- Department of Internal Medicine, University of Genoa, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Unit of Medical Genetics IRCCS G. Gaslini Institute, Genoa, Italy
| | - Paola Origone
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Unit of Medical Genetics, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Eugenia Rota
- Neurology Unit, ASL Alessandria, Novi Ligure, Italy
| | - Carlo Minetti
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Pediatric Neurology and Muscular Diseases Unit, IRCCS G. Gaslini Institute, Genoa, Italy
| | - Claudio Bruno
- Centre of Experimental and Translational Myology, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Angelo Schenone
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Unit of Neurology, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Paola Mandich
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Unit of Medical Genetics, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Chiara Fiorillo
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Pediatric Neurology and Muscular Diseases Unit, IRCCS G. Gaslini Institute, Genoa, Italy
| | - Marina Grandis
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences, University of Genova, Unit of Neurology, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
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Nicolau S, Milone M, Tracy JA, Mills JR, Triplett JD, Liewluck T. Immune-mediated necrotizing myopathy: Unusual presentations of a treatable disease. Muscle Nerve 2021; 64:734-739. [PMID: 34617293 DOI: 10.1002/mus.27435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 09/28/2021] [Accepted: 10/03/2021] [Indexed: 01/21/2023]
Abstract
INTRODUCTION/AIMS Immune-mediated necrotizing myopathy (IMNM) is an immune-mediated myopathy typically presenting with progressive subacute weakness and characteristic, but nonspecific, myopathological findings. Atypical cases however can mimic other inherited or acquired myopathies, depriving patients of treatment. We describe a cohort of such patients. METHODS We retrospectively identified IMNM patients who either previously carried a diagnosis of an inherited myopathy established on clinicopathological grounds or whose muscle biopsies displayed atypical features suggestive of a different myopathy. RESULTS Among 131 IMNM patients, seven previously unreported patients (5%) met one of the above criteria. Three patients were diagnosed with limb-girdle muscular dystrophy on the basis of a chronic progressive course of weakness and family history of myopathy or cardiomyopathy. The other four patients displayed atypical histological features (two prominent mitochondrial abnormalities, one myofibrillar pathology, and one granulomatous inflammation). Immunostaining of biopsies from 12 additional IMNM patients did not identify myofibrillar pathology. The patient with granulomatous inflammation was known to have pulmonary sarcoidosis. Genetic testing for inherited myopathies was unrevealing. Antibodies against 3-hydroxy-3-methylglutaryl-CoA reductase or signal recognition particle were identified in 5 and 1 patients, respectively. Four patients presented with slowly progressive weakness over 3-13 y, while weakness was subacute over ≤6 mo in three patients. All patients responded to immunomodulatory therapy. DISCUSSION Atypical clinical and histological features can occur in IMNM patients, causing delays in diagnosis and treatment. Clinicians should, therefore, consider IMNM in the differential diagnosis of unexplained proximal myopathies in spite of atypical clinical and myopathological findings.
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Affiliation(s)
- Stefan Nicolau
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | - John R Mills
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Teerin Liewluck
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
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Clinical Course, Myopathology and Challenge of Therapeutic Intervention in Pediatric Patients with Autoimmune-Mediated Necrotizing Myopathy. CHILDREN-BASEL 2021; 8:children8090721. [PMID: 34572153 PMCID: PMC8470706 DOI: 10.3390/children8090721] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 11/22/2022]
Abstract
(1) Background: Immune–mediated necrotizing myopathy (IMNM) is a rare form of inflammatory muscle disease which is even more rare in pediatric patients. To increase the knowledge of juvenile IMNM, we here present the clinical findings on long-term follow-up, myopathological changes, and therapeutic strategies in two juvenile patients. (2) Methods: Investigations included phenotyping, determination of antibody status, microscopy on muscle biopsies, MRI, and response to therapeutic interventions. (3) Results: Anti-signal recognition particle (anti-SRP54) and anti- 3-hydroxy-3-methylglutarly coenzyme A reductase (anti-HMGCR) antibodies (Ab) were detected in the patients. Limb girdle presentation, very high CK-levels, and a lack of skin rash at disease-manifestation and an absence of prominent inflammatory signs accompanied by an abnormal distribution of α-dystroglycan in muscle biopsies initially hinted toward a genetically caused muscle dystrophy. Further immunostaining studies revealed an increase of proteins involved in chaperone-assisted autophagy (CASA), a finding already described in adult IMNM-patients. Asymmetrical muscular weakness was present in the anti-SRP54 positive Ab patient. After initial stabilization under therapy with intravenous immunoglobulins and methotrexate, both patients experienced a worsening of their symptoms and despite further therapy escalation, developed a permanent reduction of their muscle strength and muscular atrophy. (4) Conclusions: Diagnosis of juvenile IMNM might be complicated by asymmetric muscle weakness, lack of cutaneous features, absence of prominent inflammatory changes in the biopsy, and altered α-dystroglycan.
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Biomarker und Histologie bei idiopathischen inflammatorischen Myopathien. AKTUEL RHEUMATOL 2021. [DOI: 10.1055/a-1548-8934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
ZusammenfassungDie idiopathischen inflammatorischen Myopathien (IIM) sind eine Gruppe entzündlicher Muskelerkrankungen für deren Diagnosestellung, Verlaufsbeurteilung, Prognoseabschätzung und Risikostratifizierung Biomarker eine jeweils essentielle Rolle spielen. Biomarker in diesem Kontext können sowohl „herkömmliche“ serologische Marker wie Muskelenzyme oder Autoantikörper, histologische Marker wie entitätsspezifische inflammatorische Muster, aber auch genomische und genetische Marker sein. Der vorliegende Artikel gibt einen Überblick über bewährte und innovative Marker.
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Pestronk A, Choksi R. Pathology Features of Immune and Inflammatory Myopathies, Including a Polymyositis Pattern, Relate Strongly to Serum Autoantibodies. J Neuropathol Exp Neurol 2021; 80:812-820. [PMID: 34363679 DOI: 10.1093/jnen/nlab071] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We asked whether myopathology features of immune or inflammatory myopathies (IIM), without reference to clinical or laboratory attributes, correlate with serum autoantibodies. Retrospective study included 148 muscle biopsies with: B-cell inflammatory foci (BIM), myovasculopathy, perimysial pathology (IMPP), myofiber necrosis without perimysial or vessel damage or inflammation (MNec), inflammation and myofiber vacuoles or mitochondrial pathology (IM-VAMP), granulomas, chronic graft-versus-host disease, or none of these criteria. 18 IIM-related serum autoantibodies were tested. Strong associations between myopathology and autoantibodies included: BIM with PM/Scl-100 (63%; odds ratio [OR] = 72); myovasculopathies with TIF1-γ or NXP2 (70%; OR = 72); IMPP with Jo-1 (33%; OR = 28); MNec with SRP54 (23%; OR = 37); IM-VAMP with NT5C1a (95%; OR = 83). Hydroxymethylglutaryl-CoA reductase (HMGCR) antibodies related to presence of myofiber necrosis across all groups (82%; OR = 9), but not to one IIM pathology group. Our results validate characterizations of IIM by myopathology features, showing strong associations with some serum autoantibodies, another objective IIM-related marker. BIM with PM/Scl-100 antibodies can be described pathologically as polymyositis. Tif1-γ and NXP2 antibodies are both common in myovasculopathies. HMGCR antibodies associate with myofiber necrosis, but not one IIM pathology subtype. Relative association strengths of IIM-related autoantibodies to IIM myopathology features versus clinical characteristics require further study.
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Affiliation(s)
- Alan Pestronk
- From the Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA (AP, RC).,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA (AP)
| | - Rati Choksi
- From the Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA (AP, RC)
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Lee KH, Gao Y, Lau V. Statin-associated anti-3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) myopathy: Imaging findings on thigh-muscle magnetic resonance imaging (MRI) in six patients. Muscle Nerve 2021; 64:500-504. [PMID: 34297419 DOI: 10.1002/mus.27382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/08/2022]
Abstract
INTRODUCTION/AIMS Anti-3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) myopathy is a rare but serious complication of statin use. The aim of this study was to describe the imaging features of statin-associated anti-HMGCR myopathy on thigh muscle magnetic resonance imaging (MRI). METHODS Thigh muscle MRI images of six patients with statin-associated anti-HMGCR myopathy were reviewed for muscle edema, fatty replacement, and fascial edema in four compartments of each thigh: gluteal, anterior, medial, and posterior. Signal intensity ratio (SIR) was calculated in 17 muscles in both thighs on T2-weighted fat-suppressed images. Intracompartmental comparison of T2 SIRs of different muscles were performed. RESULTS All patients demonstrated bilateral symmetrical pan-compartmental muscle edema. Three patients had fatty infiltration, involving gluteal and/or posterior compartments. In the anterior compartment, rectus femoris and vastus lateralis most frequently demonstrated the highest T2 SIR. In the posterior compartment, semimembranosus most frequently demonstrated the highest T2 SIR. The long head of the biceps femoris always had a higher T2 SIR than the short head. DISCUSSION Statin-associated anti-HMGCR myopathy commonly demonstrates bilateral symmetrical pan-compartmental edema on thigh muscle MRI, with anterolateral predilection in the anterior compartment, and greater involvement of the semimembranosus with relative sparing of the short head of the biceps femoris in the posterior compartment. These observations can contribute to the diagnosis of statin-associated anti-HMGCR myopathy.
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Affiliation(s)
- Kam-Ho Lee
- Department of Radiology, Queen Mary Hospital, Hong Kong
| | - Yuan Gao
- Division of Neurology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong
| | - Vince Lau
- Department of Radiology, Queen Mary Hospital, Hong Kong
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Torri F, Ali G, Chico L, Siciliano G, Ricci G. Anti-HMGCR antibodies and asymptomatic hyperCKemia. A case report. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2021; 40:105-108. [PMID: 34355128 DOI: 10.36185/2532-1900-050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 06/14/2021] [Indexed: 11/03/2022]
Abstract
Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) related myositis is a form of immune-mediated necrotizing myopathy (IMNM). Anti-HMGCR autoantibodies target HMGCR, a glycoprotein linked to the endoplasmic reticulum implied in the cholesterol synthesis pathway, and exert a pathogenic effect on skeletal muscle cells. More than 60% of patients affected by HMGCR-related myositis shares statin-exposure in their medical history. Patients commonly experience CK levels elevation, myalgia, muscle weakness and soreness at variable extent, which manifest acutely or sub acutely with a progressively worsening course, in some cases mimicking limb-girdle muscular dystrophies (LGMD) phenotype and treatment is based on an immunosuppressive strategy. Here we present the peculiar case of a previously statins-exposed 72 y.o. asymptomatic man with persistent moderate hyperCKemia and high levels of anti-HMGCR, in which pharmacotherapy has not been initiated yet, while a wait-and-see approach has been adopted instead.
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Affiliation(s)
- Francesca Torri
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa, Italy
| | - Greta Ali
- Department of Surgical Pathology, Medical, Molecular, and Critical Area, University of Pisa, Pisa, Italy
| | - Lucia Chico
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa, Italy
| | - Gabriele Siciliano
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa, Italy
| | - Giulia Ricci
- Department of Clinical and Experimental Medicine, Neurological Clinic, University of Pisa, Pisa, Italy
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Nicolau S, Milone M, Liewluck T. Guidelines for genetic testing of muscle and neuromuscular junction disorders. Muscle Nerve 2021; 64:255-269. [PMID: 34133031 DOI: 10.1002/mus.27337] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 12/24/2022]
Abstract
Despite recent advances in the understanding of inherited muscle and neuromuscular junction diseases, as well as the advent of a wide range of genetic tests, patients continue to face delays in diagnosis of sometimes treatable disorders. These guidelines outline an approach to genetic testing in such disorders. Initially, a patient's phenotype is evaluated to identify myopathies requiring directed testing, including myotonic dystrophies, facioscapulohumeral muscular dystrophy, oculopharyngeal muscular dystrophy, mitochondrial myopathies, dystrophinopathies, and oculopharyngodistal myopathy. Initial investigation in the remaining patients is generally a comprehensive gene panel by next-generation sequencing. Broad panels have a higher diagnostic yield and can be cost-effective. Due to extensive phenotypic overlap and treatment implications, genes responsible for congenital myasthenic syndromes should be included when evaluating myopathy patients. For patients whose initial genetic testing is negative or inconclusive, phenotypic re-evaluation is warranted, along with consideration of genes and variants not included initially, as well as their acquired mimickers.
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Affiliation(s)
- Stefan Nicolau
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Teerin Liewluck
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
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De Ridder W, De Jonghe P, Straub V, Baets J. High prevalence of sporadic late-onset nemaline myopathy in a cohort of whole-exome sequencing negative myopathy patients. Neuromuscul Disord 2021; 31:1154-1160. [PMID: 34172358 DOI: 10.1016/j.nmd.2021.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/10/2021] [Accepted: 04/26/2021] [Indexed: 10/21/2022]
Abstract
Sporadic late-onset nemaline myopathy (SLONM) is an enigmatic, supposedly very rare, putatively immune-mediated late-onset myopathy, typically presenting with subacutely progressive limb-girdle muscular weakness, yet slowly progressing cases have been described too. We systematically studied (para)clinical and histopathological findings in a cohort of 18 isolated yet suspected inherited myopathy patients, showing late-onset, slowly progressive limb-girdle muscle weakness, remaining unsolved after whole-exome sequencing. The presence of a monoclonal gammopathy of unknown significance (MGUS) and anti-HMGCR antibodies was determined. Biopsies were systematically re-evaluated and systematic immunohistochemical and electron microscopy studies were performed to particularly evaluate the presence of rods and/or inflammatory features. Ten patients showed rods as core feature on muscle biopsy on re-evaluation, four of these had an IgG κ MGUS in blood. As such, these ten patients represented suspected slowly progressing SLONM patients, with auxiliary data supporting this diagnosis: 1) additional muscle biopsy features pointing towards Z-disk and myofibrillar pathology; 2) a common selective pattern of muscle involvement on MRI; 3) inflammatory features on muscle biopsy. Findings in this proof-of-concept study highlight difficulties in reliably diagnosing slowly progressing SLONM and the probably underestimated prevalence of this entity in cohorts of whole exome sequencing negative myopathy patients, initially considered having an inherited myopathy.
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Affiliation(s)
- Willem De Ridder
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; The Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; The Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Peter De Jonghe
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; The Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; The Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Volker Straub
- The John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, United Kingdom
| | - Jonathan Baets
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; The Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium; The Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium.
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