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Inan B, Orhan IG, Bekircan-Kurt CE, Erdem-Ozdamar S, Tan E. Clinical and laboratory remission with rituximab in anti-MuSK-positive myasthenia gravis. Ir J Med Sci 2024:10.1007/s11845-024-03763-w. [PMID: 39088160 DOI: 10.1007/s11845-024-03763-w] [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: 01/03/2024] [Accepted: 07/18/2024] [Indexed: 08/02/2024]
Abstract
BACKGROUND Increasing data are available on the use and efficacy of rituximab (RTX) in patients with anti-muscle-specific tyrosine kinase (MuSK)-positive myasthenia gravis (MG), especially those steroid-dependent or unresponsive to traditional immunotherapies. AIMS We aimed to evaluate the clinical characteristics and treatment responses of adult patients with generalized anti-MuSK-positive MG treated with RTX. METHODS We retrospectively recruited 16 patients who were on RTX, between January 2010 and September 2023. RTX was given 1000 mg/day intravenously twice, two weeks apart. Maintenance treatment was administered at intervals of 3-6 months based on clinical evaluation. The outcome was assessed by Myasthenia Gravis Foundation of America (MGFA) and Myasthenia Gravis Status and Treatment Intensity (MGSTI) scores. Additionally, anti-MuSK antibody levels were retested after treatment in all patients except one. RESULTS Twelve patients were female. The mean age at disease onset was 35.3 ± 17.3 years. The median duration between disease onset and RTX administration was 2.4 years (min-max: 0.5-36.5 years). The worst MGFA class before RTX was between IIIb-V. After RTX treatment, 81.3% of patients achieved MGFA minimal manifestations or better and MGSTI level 1 or better. Anti-MuSK antibodies became negative in 12 patients, while they remained positive in three. The changes in antibody levels seemed associated with clinical outcomes. CONCLUSIONS RTX is an effective treatment in anti-MuSK-positive MG. Furthermore, our results support the inhibition of antibody production by RTX and we recommend monitoring anti-MuSK antibody titers to follow disease progression and treatment response.
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Affiliation(s)
- Berin Inan
- Department of Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Irem Gul Orhan
- Department of Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | | | - Sevim Erdem-Ozdamar
- Department of Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Ersin Tan
- Department of Neurology, Hacettepe University Faculty of Medicine, Ankara, Turkey
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Falso S, Gessi M, Marini S, Benvenuto R, Sabatelli E, D'Amati A, Marini M, Evoli A, Iorio R. Cancer Frequency in MuSK Myasthenia Gravis and Histological Evidence of Paraneoplastic Etiology. Ann Neurol 2024. [PMID: 39007444 DOI: 10.1002/ana.27033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 06/04/2024] [Accepted: 07/02/2024] [Indexed: 07/16/2024]
Abstract
Cancer frequency in muscle-specific kinase myasthenia gravis (MuSK-MG) has not yet been explored and the mechanisms leading to the formation of MuSK IgG remain elusive. We aimed to explore cancer frequency in MuSK-MG patients and to assess MuSK expression in cancer cells from 2 tumors occurred in this cohort. Immunohistochemistry on tumor specimens revealed the expression of MuSK in the cancer cells from primary mediastinal B cell lymphoma and endometrial carcinoma. Twenty-one males and 73 females were enrolled. Fifteen cancers occurred in 13 of 94 patients (13.8%). Patients with cancer were significantly older at time of MuSK-MG onset. ANN NEUROL 2024.
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Affiliation(s)
- Silvia Falso
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Marco Gessi
- Neuropathology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | - Sofia Marini
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Roberta Benvenuto
- Neuropathology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | - Eleonora Sabatelli
- Neurology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | - Antonio D'Amati
- Gynecopathology and Breast Pathology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | - Martina Marini
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Amelia Evoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
- Neurology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | - Raffaele Iorio
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy
- Neurology Unit, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
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3
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Gayathri D, Nandasiri S, Pathirana G. A Case Report of MuSK Antibody-Positive Myasthenia Gravis. Cureus 2024; 16:e61820. [PMID: 38975540 PMCID: PMC11227625 DOI: 10.7759/cureus.61820] [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] [Accepted: 06/06/2024] [Indexed: 07/09/2024] Open
Abstract
Myasthenia gravis (MG) is characterized by muscle weakness and fatigability. The presence of autoantibodies against the acetylcholine receptors (AChR) at the neuromuscular junction, which impairs neuromuscular transmission, is the hallmark of the disease. However, a minority of patients have antibodies against muscle-specific tyrosine kinase (MuSK), which is referred to as MuSK myasthenia gravis (MuSK-MG). We present the case of a 56-year-old female patient presenting with progressive dysphagia, slurred speech, and fatigable ptosis. She had a positive icepack test and a positive repetitive nerve stimulation test (RNST). Her AchR antibodies were negative, and the MuSK antibodies were positive. Her clinical response to pyridostigmine was unsatisfactory, but she had a good recovery with rituximab. Even though MuSK-MG is rare, it is an important diagnostic consideration, particularly in patients presenting with atypical symptoms or lacking AChR antibodies and in patients who have a poor response to conventional treatment. Acetylcholinesterase inhibitors, corticosteroids, immunosuppressants, and newer biologic agents targeting B cells are some of the treatments.
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Li Y, Yang S, Dong X, Duan W, Jiang F, Chen K, Zhou Q, Cai H, Yang H. Diagnostic value of antibody concentration ratio for treatment-refractory myasthenia gravis. Neurol Sci 2024:10.1007/s10072-024-07601-w. [PMID: 38780854 DOI: 10.1007/s10072-024-07601-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/16/2024] [Indexed: 05/25/2024]
Abstract
OBJECTIVE This study aimed to assess the diagnostic potential of the Antibody concentration ratio in identifying treatment-refractory myasthenia gravis (MG). METHODS A retrospective analysis was conducted on 116 MG patients who underwent antibody detection at least twice between June 1, 2015, and June 1, 2023. Demographic and clinical characteristics were collated to ascertain their association with refractory MG. The Antibody Concentration Ratio was applied to determine treatment response, using the International Consensus Guidance criteria as the reference standard. The area under nonparametric receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy were calculated to assess the diagnostic efficacy of the Antibody concentration ratio following consecutive immunotherapy relative to initial antibody concentrations for refractory MG. RESULTS 19 out of 116 patients were unequivocally diagnosed with refractory MG. A significant correlation was found between the Antibody Concentration Ratio and refractory MG status in treatment-refractory and treatment-responsive patients. Subsequently, the AUC demonstrated the robust diagnostic capability of the Antibody concentration ratio for refractory MG, with an AUC of 0.8709 (95% CI: 0.7995-0.9422, p < 0.0001). The optimal cut-off value stood at 0.8903, exhibiting a sensitivity of 94.74% (95% CI: 75.36%-99.73%), a specificity of 68.04% (95% CI: 58.23%-76.48%), and accuracy of 72.41% (95% CI: 64.28%-80.54%). CONCLUSION Elevated Antibody Concentration Ratio is intrinsically linked with refractory MG and exhibits potential as an diagnostic biomarker for the condition.
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Affiliation(s)
- Yi Li
- Department of Neurology, Research Center for Neuroimmune and Neuromuscular disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China
| | - Shumei Yang
- Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China
| | - Xiaohua Dong
- Department of Neurology, Research Center for Neuroimmune and Neuromuscular disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China
| | - Weiwei Duan
- Department of Neurology, Research Center for Neuroimmune and Neuromuscular disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China
| | - Fei Jiang
- Department of Neurology, Research Center for Neuroimmune and Neuromuscular disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China
| | - Kangzhi Chen
- Department of Neurology, Research Center for Neuroimmune and Neuromuscular disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China
| | - Qian Zhou
- Department of Neurology, Research Center for Neuroimmune and Neuromuscular disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China
| | - Haobin Cai
- Department of Neurology, Research Center for Neuroimmune and Neuromuscular disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China
| | - Huan Yang
- Department of Neurology, Research Center for Neuroimmune and Neuromuscular disorders, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410000, Hunan, China.
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Herbst R, Huijbers MG, Oury J, Burden SJ. Building, Breaking, and Repairing Neuromuscular Synapses. Cold Spring Harb Perspect Biol 2024; 16:a041490. [PMID: 38697654 PMCID: PMC11065174 DOI: 10.1101/cshperspect.a041490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
A coordinated and complex interplay of signals between motor neurons, skeletal muscle cells, and Schwann cells controls the formation and maintenance of neuromuscular synapses. Deficits in the signaling pathway for building synapses, caused by mutations in critical genes or autoantibodies against key proteins, are responsible for several neuromuscular diseases, which cause muscle weakness and fatigue. Here, we describe the role that four key genes, Agrin, Lrp4, MuSK, and Dok7, play in this signaling pathway, how an understanding of their mechanisms of action has led to an understanding of several neuromuscular diseases, and how this knowledge has contributed to emerging therapies for treating neuromuscular diseases.
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Affiliation(s)
- Ruth Herbst
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | - Maartje G Huijbers
- Department of Human Genetics, Leiden University Medical Centre LUMC, 2300 RC Leiden, the Netherlands
- Department of Neurology, Leiden University Medical Centre LUMC, 2333 ZA Leiden, the Netherlands
| | - Julien Oury
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, New York 10016, USA
| | - Steven J Burden
- Neurology Department, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA
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Gilhus NE, Andersen H, Andersen LK, Boldingh M, Laakso S, Leopoldsdottir MO, Madsen S, Piehl F, Popperud TH, Punga AR, Schirakow L, Vissing J. Generalized myasthenia gravis with acetylcholine receptor antibodies: A guidance for treatment. Eur J Neurol 2024; 31:e16229. [PMID: 38321574 PMCID: PMC11236053 DOI: 10.1111/ene.16229] [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: 10/10/2023] [Revised: 01/16/2024] [Accepted: 01/16/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND Generalized myasthenia gravis (MG) with antibodies against the acetylcholine receptor is a chronic disease causing muscle weakness. Access to novel treatments warrants authoritative treatment recommendations. The Nordic countries have similar, comprehensive health systems, mandatory health registers, and extensive MG research. METHODS MG experts and patient representatives from the five Nordic countries formed a working group to prepare treatment guidance for MG based on a systematic literature search and consensus meetings. RESULTS Pyridostigmine represents the first-line symptomatic treatment, while ambenonium and beta adrenergic agonists are second-line options. Early thymectomy should be undertaken if a thymoma, and in non-thymoma patients up to the age of 50-65 years if not obtaining remission on symptomatic treatment. Most patients need immunosuppressive drug treatment. Combining corticosteroids at the lowest possible dose with azathioprine is recommended, rituximab being an alternative first-line option. Mycophenolate, methotrexate, and tacrolimus represent second-line immunosuppression. Plasma exchange and intravenous immunoglobulin are used for myasthenic crises and acute exacerbations. Novel complement inhibitors and FcRn blockers are effective and fast-acting treatments with promising safety profiles. Their use depends on local availability, refunding policies, and cost-benefit analyses. Adapted physical training is recommended. Planning of pregnancies with optimal treatment, information, and awareness of neonatal MG is necessary. Social support and adaptation of work and daily life activities are recommended. CONCLUSIONS Successful treatment of MG rests on timely combination of different interventions. Due to spontaneous disease fluctuations, comorbidities, and changes in life conditions, regular long-term specialized follow-up is needed. Most patients do reasonably well but there is room for further improvement. Novel treatments are promising, though subject to restricted access due to costs.
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Affiliation(s)
- Nils Erik Gilhus
- Department of NeurologyHaukeland University HospitalBergenNorway
- Department of Clinical MedicineUniversity of BergenBergenNorway
| | | | - Linda Kahr Andersen
- Copenhagen Neuromuscular Center, Department of NeurologyCopenhagen University HospitalCopenhagenDenmark
| | | | - Sini Laakso
- Department of Neurology, Brain CenterHelsinki University HospitalHelsinkiFinland
- Translational Immunology Research ProgramUniversity of HelsinkiHelsinkiFinland
| | | | - Sidsel Madsen
- The National Rehabilitation Center for Neuromuscular DiseasesAarhusDenmark
| | - Fredrik Piehl
- Department of Clinical NeuroscienceKarolinska InstitutetStockholmSweden
- Department of NeurologyKarolinska University HospitalStockholmSweden
| | | | - Anna Rostedt Punga
- Department of Medical SciencesUppsala UniversityUppsalaSweden
- Department of Clinical NeurophysiologyUppsala University HospitalUppsalaSweden
| | | | - John Vissing
- Copenhagen Neuromuscular Center, Department of NeurologyCopenhagen University HospitalCopenhagenDenmark
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7
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Banerjee A, Nathoo N, Purdy K, Puznak K, Siddiqi Z, Zochodne DW. Muscle-Specific Tyrosine Kinase-Associated Myasthenia Gravis with Microscopic Thymoma. Can J Neurol Sci 2024; 51:435-437. [PMID: 37066702 DOI: 10.1017/cjn.2023.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Affiliation(s)
- Ankur Banerjee
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Nabeela Nathoo
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Kaylynn Purdy
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Kimbal Puznak
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada
| | - Zaeem Siddiqi
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Douglas W Zochodne
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
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Koneczny I, Mané-Damas M, Zong S, De Haas S, Huda S, van Kruining D, Damoiseaux J, De Rosa A, Maestri M, Guida M, Molenaar P, Van Damme P, Fichtenbaum A, Perkmann T, De Baets M, Lazaridis K, Zouvelou V, Tzartos S, Ricciardi R, Losen M, Martinez-Martinez P. A retrospective multicenter study on clinical and serological parameters in patients with MuSK myasthenia gravis with and without general immunosuppression. Front Immunol 2024; 15:1325171. [PMID: 38715598 PMCID: PMC11074957 DOI: 10.3389/fimmu.2024.1325171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 03/25/2024] [Indexed: 06/19/2024] Open
Abstract
Introduction Muscle-specific kinase (MuSK)- myasthenia gravis (MG) is caused by pathogenic autoantibodies against MuSK that correlate with disease severity and are predominantly of the IgG4 subclass. The first-line treatment for MuSK-MG is general immunosuppression with corticosteroids, but the effect of treatment on IgG4 and MuSK IgG4 levels has not been studied. Methods We analyzed the clinical data and sera from 52 MuSK-MG patients (45 female, 7 male, median age 49 (range 17-79) years) from Italy, the Netherlands, Greece and Belgium, and 43 AChR-MG patients (22 female, 21 male, median age 63 (range 2-82) years) from Italy, receiving different types of immunosuppression, and sera from 46 age- and sex-matched non-disease controls (with no diagnosed diseases, 38 female, 8 male, median age 51.5 (range 20-68) years) from the Netherlands. We analyzed the disease severity (assessed by MGFA or QMG score), and measured concentrations of MuSK IgG4, MuSK IgG, total IgG4 and total IgG in the sera by ELISA, RIA and nephelometry. Results We observed that MuSK-MG patients showed a robust clinical improvement and reduction of MuSK IgG after therapy, and that MuSK IgG4 concentrations, but not total IgG4 concentrations, correlated with clinical severity. MuSK IgG and MuSK IgG4 concentrations were reduced after immunosuppression in 4/5 individuals with before-after data, but data from non-linked patient samples showed no difference. Total serum IgG4 levels were within the normal range, with IgG4 levels above threshold (1.35g/L) in 1/52 MuSK-MG, 2/43 AChR-MG patients and 1/45 non-disease controls. MuSK-MG patients improved within the first four years after disease onset, but no further clinical improvement or reduction of MuSK IgG4 were observed four years later, and only 14/52 (26.92%) patients in total, of which 13 (93.3%) received general immunosuppression, reached clinical remission. Discussion We conclude that MuSK-MG patients improve clinically with general immunosuppression but may require further treatment to reach remission. Longitudinal testing of individual patients may be clinically more useful than single measurements of MuSK IgG4. No significant differences in the serum IgG4 concentrations and IgG4/IgG ratio between AChR- and MuSK-MG patients were found during follow-up. Further studies with larger patient and control cohorts are necessary to validate the findings.
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Affiliation(s)
- Inga Koneczny
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Marina Mané-Damas
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Shenghua Zong
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Sander De Haas
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Saif Huda
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Department of Neurology, Walton Centre National Health Service (NHS) Foundation Trust, Liverpool, United Kingdom
| | - Daan van Kruining
- Department of Psychiatry and Neuropsychology, Maastricht University, Maastricht, Netherlands
| | - Jan Damoiseaux
- Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, Netherlands
| | - Anna De Rosa
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | - Michelangelo Maestri
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | - Melania Guida
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | - Peter Molenaar
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Philip Van Damme
- Neurology Department, University Hospital, Leuven, Belgium
- Department of Neurosciences, Center for Brain & Disease Research, VIB, Leuven, Belgium
| | - Andreas Fichtenbaum
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Thomas Perkmann
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Marc De Baets
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | | | - Vasiliki Zouvelou
- 1stNeurology Department, National and Kapodistrian University of Athens, Athens, Greece
| | - Socrates Tzartos
- Department of Immunology, Hellenic Pasteur Institute, Athens, Greece
- Department of Neuroimmunology, Tzartos NeuroDiagnostics, Athens, Greece
| | - Roberta Ricciardi
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
- Cardio Thoracic and Vascular Surgery Department, University of Pisa, Pisa, Italy
| | - Mario Losen
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Pilar Martinez-Martinez
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands
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Dziadkowiak E, Baczyńska D, Waliszewska-Prosół M. MuSK Myasthenia Gravis-Potential Pathomechanisms and Treatment Directed against Specific Targets. Cells 2024; 13:556. [PMID: 38534400 DOI: 10.3390/cells13060556] [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: 02/13/2024] [Revised: 03/17/2024] [Accepted: 03/19/2024] [Indexed: 03/28/2024] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease in which autoantibodies target structures within the neuromuscular junction, affecting neuromuscular transmission. Muscle-specific tyrosine kinase receptor-associated MG (MuSK-MG) is a rare, often more severe, subtype of the disease with different pathogenesis and specific clinical features. It is characterized by a more severe clinical course, more frequent complications, and often inadequate response to treatment. Here, we review the current state of knowledge about potential pathomechanisms of the MuSK-MG and their therapeutic implications as well as ongoing research in this field, with reference to key points of immune-mediated processes involved in the background of myasthenia gravis.
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Affiliation(s)
- Edyta Dziadkowiak
- Department of Neurology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland
| | - Dagmara Baczyńska
- Department of Molecular and Cellular Biology, Wroclaw Medical University, Borowska 211A, 50-556 Wroclaw, Poland
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Kwegyir-Aggrey A, Meiling JB, Miller NJ, Gandhi Mehta RK. An Unusual Presentation of MuSK-Myasthenia Gravis With Bladder Incontinence Responding to Rituximab Treatment: A Case Report and Review of the Literature. J Clin Neuromuscul Dis 2024; 25:145-146. [PMID: 38446087 DOI: 10.1097/cnd.0000000000000470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Affiliation(s)
- Abena Kwegyir-Aggrey
- Department of Neurology, Wake Forest University School of Medicine, Winston-Salem, NC
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Iorio R. Myasthenia gravis: the changing treatment landscape in the era of molecular therapies. Nat Rev Neurol 2024; 20:84-98. [PMID: 38191918 DOI: 10.1038/s41582-023-00916-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2023] [Indexed: 01/10/2024]
Abstract
Myasthenia gravis (MG) is an autoimmune disorder that affects the neuromuscular junction, leading to muscle weakness and fatigue. MG is caused by antibodies against the acetylcholine receptor (AChR), the muscle-specific kinase (MuSK) or other AChR-related proteins that are expressed in the postsynaptic muscle membrane. The standard therapeutic approach for MG has relied on acetylcholinesterase inhibitors, corticosteroids and immunosuppressants, which have shown good efficacy in improving MG-related symptoms in most people with the disease; however, these therapies can carry a considerable burden of long-term adverse effects. Moreover, up to 15% of individuals with MG exhibit limited or no response to these standard therapies. The emergence of molecular therapies, including monoclonal antibodies, B cell-depleting agents and chimeric antigen receptor T cell-based therapies, has the potential to revolutionize the MG treatment landscape. This Review provides a comprehensive overview of the progress achieved in molecular therapies for MG associated with AChR antibodies and MuSK antibodies, elucidating both the challenges and the opportunities these therapies present to the field. The latest developments in MG treatment are described, exploring the potential for personalized medicine approaches.
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Affiliation(s)
- Raffaele Iorio
- Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy.
- Neurology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.
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12
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Tannemaat MR, Huijbers MG, Verschuuren JJGM. Myasthenia gravis-Pathophysiology, diagnosis, and treatment. HANDBOOK OF CLINICAL NEUROLOGY 2024; 200:283-305. [PMID: 38494283 DOI: 10.1016/b978-0-12-823912-4.00026-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Myasthenia gravis (MG) is an autoimmune disease characterized by dysfunction of the neuromuscular junction resulting in skeletal muscle weakness. It is equally prevalent in males and females, but debuts at a younger age in females and at an older age in males. Ptosis, diplopia, facial bulbar weakness, and limb weakness are the most common symptoms. MG can be classified based on the presence of serum autoantibodies. Acetylcholine receptor (AChR) antibodies are found in 80%-85% of patients, muscle-specific kinase (MuSK) antibodies in 5%-8%, and <1% may have low-density lipoprotein receptor-related protein 4 (Lrp4) antibodies. Approximately 10% of patients are seronegative for antibodies binding the known disease-related antigens. In patients with AChR MG, 10%-20% have a thymoma, which is usually detected at the onset of the disease. Important differences between clinical presentation, treatment responsiveness, and disease mechanisms have been observed between these different serologic MG classes. Besides the typical clinical features and serologic testing, the diagnosis can be established with additional tests, including repetitive nerve stimulation, single fiber EMG, and the ice pack test. Treatment options for MG consist of symptomatic treatment (such as pyridostigmine), immunosuppressive treatment, or thymectomy. Despite the treatment with symptomatic drugs, steroid-sparing immunosuppressants, intravenous immunoglobulins, plasmapheresis, and thymectomy, a large proportion of patients remain chronically dependent on corticosteroids (CS). In the past decade, the number of treatment options for MG has considerably increased. Advances in the understanding of the pathophysiology have led to new treatment options targeting B or T cells, the complement cascade, the neonatal Fc receptor or cytokines. In the future, these new treatments are likely to reduce the chronic use of CS, diminish side effects, and decrease the number of patients with refractory disease.
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Affiliation(s)
- Martijn R Tannemaat
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Maartje G Huijbers
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands; Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
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13
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Iorio R, Lennon VA. Paraneoplastic autoimmune neurologic disorders associated with thymoma. HANDBOOK OF CLINICAL NEUROLOGY 2024; 200:385-396. [PMID: 38494291 DOI: 10.1016/b978-0-12-823912-4.00008-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Thymoma is often associated with paraneoplastic neurologic diseases. Neural autoantibody testing is an important tool aiding diagnosis of thymoma and its autoimmune neurologic complications. Autoantibodies specific for muscle striational antigens and ion channels of the ligand-gated nicotinic acetylcholine receptor superfamily are the most prevalent biomarkers. The autoimmune neurologic disorders associating most commonly with thymoma are myasthenia gravis (MG), peripheral nerve hyperexcitability (neuromyotonia and Morvan syndrome), dysautonomia, and encephalitis. Patients presenting with these neurologic disorders should be screened for thymoma at diagnosis. Although they can cause profound disability, they usually respond to immunotherapy and treatment of the thymoma. Worsening of the neurologic disorder following surgical removal of a thymoma may herald tumor recurrence. Prompt recognition of paraneoplastic neurologic disorders is critical for patient management. A multidisciplinary approach is required for optimal management of neurologic autoimmunity associated with thymoma.
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Affiliation(s)
- Raffaele Iorio
- Neurology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy.
| | - Vanda A Lennon
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States; Department of Neurology, Mayo Clinic, Rochester, MN, United States; Department of Immunology, Mayo Clinic, Rochester, MN, United States
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14
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Zhen L, Zhao X, Li W, Wu J, Shang H, Chen S, Zhu X, Wang Y, Yu X, Hu G, Sun Z, Zhang Y, Zhang J, Fang H, Zhang Y, Zhang Q, Cui X, Lv J, Yang J, Gao F. Effectiveness of early glucocorticoids in myasthenia gravis: a retrospective cohort study. Front Neurol 2023; 14:1259484. [PMID: 38187148 PMCID: PMC10770254 DOI: 10.3389/fneur.2023.1259484] [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: 07/16/2023] [Accepted: 11/23/2023] [Indexed: 01/09/2024] Open
Abstract
Purpose This study aimed to clarify the effect of early glucocorticoid (GC) application on achieving minimal manifestation (MM) status or better in the treatment of myasthenia gravis (MG) in the early clinical phase. Methods A retrospective analysis was performed using data from 336 patients with MG who received GC therapy from January 2015 to September 2022 in the Zhengzhou University Henan Institute of Medical and Pharmaceutical Sciences Myasthenia Gravis Biobank (ZMB). Patients were divided into two groups: the early mono-GC group (treated with GC within 6 months of MG onset) and the delayed mono-GC group. Results Kaplan-Meier analysis showed that the early mono-GC group achieved MM status earlier and more frequently than the delayed mono-GC group (log-rank test, p = 0.0082; hazard ratio [HR], 1.66; p = 0.011). The early mono-GC group had a lower maintenance oral GC dose than the delayed mono-GC group. In multivariate Cox regression analysis, early mono-GC (HR, 1.50; p = 0.043), early-onset MG (EOMG) (HR, 1.74; p = 0.034), and ocular MG (OMG) (HR, 1.90; p = 0.007) were associated with MM status or better. In conclusion, early mono-GC, EOMG, and OMG were positive predictors of treatment goals. In EOMG, OMG, and acetylcholine receptor antibody-positive MG (AChR-MG) subgroups, the maintenance oral GC doses in the early mono-GC group were significantly lower than the doses in the delayed mono-GC group (p < 0.05). Conclusion Early intervention with GC led to better long-term outcomes and reduced the necessary maintenance dose of oral GC for patients with MG. EOMG and OMG were positive predictors of MM status or better with mono-GC.
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Affiliation(s)
- Lulu Zhen
- Department of Neurology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Xue Zhao
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Wenbo Li
- Department of Neurology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Jinru Wu
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
- Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Haodong Shang
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
- BGI College, Zhengzhou University, Zhengzhou, China
| | - Shufan Chen
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
- BGI College, Zhengzhou University, Zhengzhou, China
| | - Xiaoyan Zhu
- Department of Neurology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yiren Wang
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
- Basic Medical College, Zhengzhou University, Zhengzhou, China
| | - Xiaoxiao Yu
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
- BGI College, Zhengzhou University, Zhengzhou, China
| | - Guanlian Hu
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
- BGI College, Zhengzhou University, Zhengzhou, China
| | - Zhan Sun
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
- BGI College, Zhengzhou University, Zhengzhou, China
| | - Yingna Zhang
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Jing Zhang
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Hua Fang
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yunke Zhang
- Department of Encephalopathy, First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, China
| | - Qingyong Zhang
- Myasthenia Gravis Comprehensive Diagnosis and Treatment Center, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Xinzheng Cui
- Myasthenia Gravis Comprehensive Diagnosis and Treatment Center, Henan Provincial People’s Hospital, Zhengzhou, China
| | - Jie Lv
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Junhong Yang
- Department of Encephalopathy, First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, China
| | - Feng Gao
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
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Yasuda M, Uzawa A, Kuwabara S, Suzuki S, Akamine H, Onishi Y, Ozawa Y, Kawaguchi N, Kubota T, Takahashi MP, Suzuki Y, Watanabe G, Kimura T, Sugimoto T, Samukawa M, Minami N, Masuda M, Konno S, Nagane Y, Utsugisawa K. Clinical features and outcomes of patients with muscle-specific kinase antibody-positive myasthenia gravis in Japan. J Neuroimmunol 2023; 385:578241. [PMID: 37952282 DOI: 10.1016/j.jneuroim.2023.578241] [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: 09/25/2023] [Revised: 10/31/2023] [Accepted: 11/05/2023] [Indexed: 11/14/2023]
Abstract
This study included 51 patients with muscle-specific kinase antibody-positive myasthenia gravis (MuSK-MG) from a Japanese multicenter survey to examine clinical features and outcomes. Median onset age was 37 years and female predominance was observed. All patients developed generalized symptoms and almost all (50/51) patients had bulbar symptoms. About half of the patients met the criteria for refractory MG. The refractory group had a lower age of onset, higher severity scores, and higher maximum daily doses of oral prednisolone compared to the nonrefractory group. The outcomes for MuSK-MG patients in Japan are not favorable, indicating the need for more aggressive treatment.
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Affiliation(s)
- Manato Yasuda
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Akiyuki Uzawa
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan.
| | - Satoshi Kuwabara
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Shigeaki Suzuki
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Hiroyuki Akamine
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yosuke Onishi
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yukiko Ozawa
- Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Naoki Kawaguchi
- Department of Neurology, Neurology Chiba Clinic, Chiba, Japan
| | - Tomoya Kubota
- Department of Clinical Laboratory and Biomedical Sciences, Division of Health Sciences, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masanori P Takahashi
- Department of Clinical Laboratory and Biomedical Sciences, Division of Health Sciences, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yasushi Suzuki
- Department of Neurology, National Hospital Organization Sendai Medical Center, Sendai, Japan
| | - Genya Watanabe
- Department of Neurology, National Hospital Organization Sendai Medical Center, Sendai, Japan
| | - Takashi Kimura
- Department of Neurology, Hyogo Medical University, Nishinomiya, Japan
| | - Takamichi Sugimoto
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Hiroshima, Japan
| | - Makoto Samukawa
- Department of Neurology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Naoya Minami
- Department of Neurology, National Hospital Organization Hokkaido Medical Center, Sapporo, Japan
| | - Masayuki Masuda
- Department of Neurology, Tokyo Medical University, Tokyo, Japan
| | - Shingo Konno
- Department of Neurology, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Yuriko Nagane
- Department of Neurology, Hanamaki General Hospital, Hanamaki, Japan
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16
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Paardekooper LM, Fillié-Grijpma YE, van der Sluijs-Gelling AJ, Zlei M, van Doorn R, Vermeer MH, Paunovic M, Titulaer MJ, van der Maarel SM, van Dongen JJM, Verschuuren JJ, Huijbers MG. Autoantibody subclass predominance is not driven by aberrant class switching or impaired B cell development. Clin Immunol 2023; 257:109817. [PMID: 37925120 DOI: 10.1016/j.clim.2023.109817] [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: 07/06/2023] [Revised: 09/25/2023] [Accepted: 10/25/2023] [Indexed: 11/06/2023]
Abstract
A subset of autoimmune diseases is characterized by predominant pathogenic IgG4 autoantibodies (IgG4-AID). Why IgG4 predominates in these disorders is unknown. We hypothesized that dysregulated B cell maturation or aberrant class switching causes overrepresentation of IgG4+ B cells and plasma cells. Therefore, we compared the B cell compartment of patients from four different IgG4-AID with two IgG1-3-AID and healthy donors, using flow cytometry. Relative subset abundance at all maturation stages was normal, except for a, possibly treatment-related, reduction in immature and naïve CD5+ cells. IgG4+ B cell and plasma cell numbers were normal in IgG4-AID patients, however they had a (sub)class-independent 8-fold increase in circulating CD20-CD138+ cells. No autoreactivity was found in this subset. These results argue against aberrant B cell development and rather suggest the autoantibody subclass predominance to be antigen-driven. The similarities between IgG4-AID suggest that, despite displaying variable clinical phenotypes, they share a similar underlying immune profile.
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Affiliation(s)
| | | | | | - Mihaela Zlei
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands
| | - Remco van Doorn
- Department of Dermatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Maarten H Vermeer
- Department of Dermatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Manuela Paunovic
- Department of Neurology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Maarten J Titulaer
- Department of Neurology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | - Jacques J M van Dongen
- Department of Immunology, Leiden University Medical Center, Leiden, The Netherlands; Centro de Investigación del Cáncer-Instituto de Biología Molecular y Celular del Cáncer (CIC-IBMCC, USAL-CSIC-FICUS) and Department of Medicine, University of Salamanca, Salamanca, Spain
| | - Jan J Verschuuren
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Maartje G Huijbers
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands; Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
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17
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Shiozumi T, Okada N, Matsuyama T, Yamahata Y, Ohta B. Anti-Muscle-Specific Kinase (MuSK) Antibody-Positive Myasthenia Gravis Presenting With Dyspnea in an Elderly Woman: A Case Report. Cureus 2023; 15:e50480. [PMID: 38222201 PMCID: PMC10786710 DOI: 10.7759/cureus.50480] [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] [Accepted: 12/13/2023] [Indexed: 01/16/2024] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease and represents one of the most common disorders associated with neuromuscular transmission defects. Within MG, the anti-muscle-specific kinase antibody-positive subtype (MuSK-positive MG) is rare. While it shares similarities with the common form of MG by presenting with ocular weakness, MuSK-positive MG typically presents with more atypical symptoms. Although MuSK-positive MG can lead to type 2 respiratory failure due to respiratory weakness, there have been limited reports where initial presentation involves only respiratory compromise. This study details a case of MuSK-positive MG presenting dyspnea. An 84-year-old female presented to the emergency department due to a three-day history of progressive respiratory distress, characterized by increased respiratory effort and shallow breathing, resulting in a diagnosis of type 2 respiratory failure. Despite the absence of neurological abnormalities, she tested positive for anti-muscle-specific kinase antibodies, confirming a diagnosis of MuSK-positive MG. This case highlights the significance of considering MG in the context of type 2 respiratory failure, even in the absence of typical neurological symptoms, especially in elderly patients.
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Affiliation(s)
- Tadaharu Shiozumi
- Department of Emergency Medicine, Kyoto Prefectural University of Medicine, Kyoto, JPN
| | - Nobunaga Okada
- Department of Emergency Medicine, Japanese Red Cross Society Kyoto Daiichi Hospital, Kyoto, JPN
| | - Tasuku Matsuyama
- Department of Emergency Medicine, Kyoto Prefectural University of Medicine, Kyoto, JPN
| | - Yoshihiro Yamahata
- Department of Emergency Medicine, Kyoto Prefectural University of Medicine, Kyoto, JPN
| | - Bon Ohta
- Department of Emergency Medicine, Kyoto Prefectural University of Medicine, Kyoto, JPN
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18
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Chen X, Qiu J, Gao Z, Liu B, Zhang C, Yu W, Yang J, Shen Y, Qi L, Yao X, Sun H, Yang X. Myasthenia gravis: Molecular mechanisms and promising therapeutic strategies. Biochem Pharmacol 2023; 218:115872. [PMID: 37865142 DOI: 10.1016/j.bcp.2023.115872] [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: 09/03/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/23/2023]
Abstract
Myasthenia gravis (MG) is a type of autoimmune disease caused by the blockage of neuromuscular junction transmission owing to the attack of autoantibodies on transmission-related proteins. Related antibodies, such as anti-AChR, anti-MuSK and anti-LRP4 antibodies, can be detected in most patients with MG. Although traditional therapies can control most symptoms, several challenges remain to be addressed, necessitating the development of more effective and safe treatment strategies for MG. With the in-depth exploration on the mechanism and immune targets of MG, effective therapies, especially therapies using biologicals, have been reported recently. Given the important roles of immune cells, cytokines and intercellular interactions in the pathological process of MG, B-cell targeted therapy, T-cell targeted therapy, proteasome inhibitors targeting plasma cell, complement inhibitors, FcRn inhibitors have been developed for the treatment of MG. Although these novel therapies exert good therapeutic effects, they may weaken the immunity and increase the risk of infection in MG patients. This review elaborates on the pathogenesis of MG and discusses the advantages and disadvantages of the strategies of traditional treatment and biologicals. In addition, this review emphasises that combined therapy may have better therapeutic effects and reducing the risk of side effects of treatments, which has great prospects for the treatment of MG. With the deepening of research on immunotherapy targets in MG, novel opportunities and challenges in the treatment of MG will be introduced.
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Affiliation(s)
- Xin Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Jiayi Qiu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Zihui Gao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Boya Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Chen Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Weiran Yu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Jiawen Yang
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Yuntian Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Lei Qi
- Department of Emergency Medicine, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Xinlei Yao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
| | - Hualin Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
| | - Xiaoming Yang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
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19
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Rathore G, Kang PB. Pediatric Neuromuscular Diseases. Pediatr Neurol 2023; 149:1-14. [PMID: 37757659 DOI: 10.1016/j.pediatrneurol.2023.08.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/25/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023]
Abstract
The diagnostic and referral workflow for children with neuromuscular disorders is evolving, particularly as newborn screening programs are expanding in tandem with novel therapeutic developments. However, for the children who present with symptoms and signs of potential neuromuscular disorders, anatomic localization, guided initially by careful history and physical examination, continues to be the cardinal initial step in the diagnostic evaluation. It is important to consider whether the localization is more likely to be in the lower motor neuron, peripheral nerve, neuromuscular junction, or muscle. After that, disease etiologies can be divided broadly into inherited versus acquired categories. Considerations of localization and etiologies will help generate a differential diagnosis, which in turn will guide diagnostic testing. Once a diagnosis is made, it is important to be aware of current treatment options, as a number of new therapies for some of these disorders have been approved in recent years. Families are also increasingly interested in clinical research, which may include natural history studies and interventional clinical trials. Such research has proliferated for rare neuromuscular diseases, leading to exciting advances in diagnostic and therapeutic technologies, promising dramatic changes in the landscape of these disorders in the years to come.
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Affiliation(s)
- Geetanjali Rathore
- Division of Neurology, Department of Pediatrics, University of Nebraska College of Medicine, Omaha, Nebraska
| | - Peter B Kang
- Paul and Sheila Wellstone Muscular Dystrophy Center and Department of Neurology, University of Minnesota Medical School, Minneapolis, Minnesota; Institute for Translational Neuroscience, University of Minnesota, Minneapolis, Minnesota.
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20
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Rispens T, Huijbers MG. The unique properties of IgG4 and its roles in health and disease. Nat Rev Immunol 2023; 23:763-778. [PMID: 37095254 PMCID: PMC10123589 DOI: 10.1038/s41577-023-00871-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2023] [Indexed: 04/26/2023]
Abstract
IgG4 is the least abundant subclass of IgG in human serum and has unique functional features. IgG4 is largely unable to activate antibody-dependent immune effector responses and, furthermore, undergoes Fab (fragment antigen binding)-arm exchange, rendering it bispecific for antigen binding and functionally monovalent. These properties of IgG4 have a blocking effect, either on the immune response or on the target protein of IgG4. In this Review, we discuss the unique structural characteristics of IgG4 and how these contribute to its roles in health and disease. We highlight how, depending on the setting, IgG4 responses can be beneficial (for example, in responses to allergens or parasites) or detrimental (for example, in autoimmune diseases, in antitumour responses and in anti-biologic responses). The development of novel models for studying IgG4 (patho)physiology and understanding how IgG4 responses are regulated could offer insights into novel treatment strategies for these IgG4-associated disease settings.
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Affiliation(s)
- Theo Rispens
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Amsterdam, The Netherlands
| | - Maartje G Huijbers
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
- Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
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21
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Huang X, Zhang Z, Wang Y, Xu M, Du X, Zhang Y. Circulating miRNAs drive personalized medicine based on subgroup classification in myasthenia gravis patients. Neurol Sci 2023; 44:3877-3884. [PMID: 37402938 DOI: 10.1007/s10072-023-06933-3] [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: 12/25/2022] [Accepted: 06/29/2023] [Indexed: 07/06/2023]
Abstract
Myasthenia gravis (MG) is a classic autoimmune neuromuscular disease with strong clinical heterogeneity. The concept of subgroup classification was proposed to guide the precise treatment of MG. Subgroups based on serum antibodies and clinical features include ocular MG, early-onset MG with AchR antibodies, late-onset MG with AchR antibodies, thymoma-associated MG, MuSK-associated MG, LRP4-associated MG, and seronegative MG. However, reliable objective biomarkers are still needed to reflect the individualized response to therapy. MicroRNAs (miRNAs) are small non-coding RNA molecules which can specifically bind to target genes and regulate gene expression at the post-transcriptional level, and then influence celluar biological processes. MiRNAs play an important role in the pathogenesis of autoimmune diseases, including MG. Several studies on circulating miRNAs in MG have been reported. However, there is rare systematic review to summarize the differences of these miRNAs in different subgroups of MG. Here, we summarize the potential role of circulating miRNAs in different subgroups of MG to promote personalized medicine.
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Affiliation(s)
- Xiaoyu Huang
- Department of Neurology, Affiliated Hospital of Xuzhou Medical University, No. 99 Huaihai West Road, Quanshan Distric, Xuzhou, Jiangsu, China
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Zhouao Zhang
- Department of Neurology, Affiliated Hospital of Xuzhou Medical University, No. 99 Huaihai West Road, Quanshan Distric, Xuzhou, Jiangsu, China
| | - Yingying Wang
- Department of Neurology, Affiliated Hospital of Xuzhou Medical University, No. 99 Huaihai West Road, Quanshan Distric, Xuzhou, Jiangsu, China
| | - Mingming Xu
- Department of Neurology, Affiliated Hospital of Xuzhou Medical University, No. 99 Huaihai West Road, Quanshan Distric, Xuzhou, Jiangsu, China
| | - Xue Du
- Department of Neurology, Affiliated Hospital of Xuzhou Medical University, No. 99 Huaihai West Road, Quanshan Distric, Xuzhou, Jiangsu, China
| | - Yong Zhang
- Department of Neurology, Affiliated Hospital of Xuzhou Medical University, No. 99 Huaihai West Road, Quanshan Distric, Xuzhou, Jiangsu, China.
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Koral G, Ulusoy C, Cossins J, Lazaridis K, Türkoğlu R, Dong YY, Tüzün E, Yılmaz V. Silencing of FCRLB by shRNA ameliorates MuSK-induced EAMG in mice. J Neuroimmunol 2023; 383:578195. [PMID: 37660538 DOI: 10.1016/j.jneuroim.2023.578195] [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: 03/04/2023] [Revised: 05/18/2023] [Accepted: 08/29/2023] [Indexed: 09/05/2023]
Abstract
INTRODUCTION Muscle specific kinase (MuSK) antibody positive myasthenia gravis (MG) often presents with a severe disease course and resistance to treatment. Treatment-refractory patients may respond to B cell depleting treatment methods. Our aim was to investigate whether inhibition of Fc receptor-like B (FCRLB) could effectively suppress autoimmunity without diminishing B cell counts in animal model of MG, a classical antibody-mediated autoimmune disease. METHODS Experimental autoimmune MG was induced in Balb/C mice with two s.c. immunizations with recombinant human MuSK in complete Freund's adjuvant. FCRLB was silenced with a lentiviral particle transported shRNA in myasthenic mice with a single i.p. injection during second MuSK-immunization. Control immunized mice received scrambled shRNA or saline. Mice were observed for clinical parameters for 28 days and at termination, anti-MuSK IgG, neuromuscular junction (NMJ) deposits, muscle AChR expression and lymph node B and T cell ratios were assessed by ELISA, immunofluorescence, immunoblotting and flow cytometry, respectively. RESULTS FCRLB shRNA-treated mice showed no muscle weakness or weight loss at termination. Also, they exhibited higher grip strength and muscle AChR levels, lower anti-MuSK IgG and NMJ IgG/C3 levels than control mice. Flow cytometry analysis showed that ratios of major effector lymph node B and T cell populations were not altered by FCRLB silencing. However, regulatory T and CD19 + CD5+ B cell ratios were decreased in FCRLB shRNA-group. CONCLUSION Our results provide evidence regarding involvement and therapeutic value of FCRLB in MuSK-MG. Silencing of FCRLB appears to substantially inhibit antibody production without interfering with survival of major lymphocyte populations.
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Affiliation(s)
- Gizem Koral
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Canan Ulusoy
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Judith Cossins
- Neuromuscular Disorders Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, Oxford, UK
| | | | - Recai Türkoğlu
- Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey
| | - Yin Yao Dong
- Neuromuscular Disorders Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, Oxford, UK
| | - Erdem Tüzün
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Vuslat Yılmaz
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey.
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23
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Çelebisoy N, Orujov A, Balayeva F, Özdemir HN, Ak AK, Gökçay F. Prognostic predictors of remission in ocular myasthenia gravis. Acta Neurol Belg 2023; 123:1927-1932. [PMID: 36474006 DOI: 10.1007/s13760-022-02151-4] [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: 06/18/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Ocular myasthenia gravis (OMG) constitutes 15% of all myasthenia gravis patients. METHODS One hundred eight patients with OMG followed-up for over 36 months were retrospectively evaluated regarding factors associated with remission. Demographic features, neuro-ophthalmologic findings at onset, acetylcholine receptor (AChR Ab) and muscle-specifc tyrosine kinase antibodies (MuSK Ab), thymic status, single fiber electromyography (SFEMG) results were the variables considered. RESULTS Median age of disease onset was 57 years (range 18-82 years). Clinical features at onset was isolated ptosis in 55 (50.9%) and isolated diplopia in 33 (30.6%) patients. Combined ptosis and diplopia were present in 20 (18.5%) patients. Among 75 patients with ptosis, it was unilateral in 65 (86.7%) and bilateral in 10 (13.3%). AChR Abs were found in 66 (61.1%) and MuSK Abs in 2 (1.9%) patients. SFEMG abnormality was detected in 74 (68.5%) patients. Thymoma was present in 16 (14.8%) and thymic hyperplasia in 6 (5.6%) patients. Forty-one patients (37.9%) had been treated with pyridostigmine alone. Sixty-seven (62%) patients were given immunosupressive drugs. In 53 (49.1%) prednisone was used and in 14 (12.9%) patients it was combined with azathioprine. Thymectomy was performed in all 16 patients with thymoma. Complete stable remission (CSR) was achieved in 49 (45.4%) patients. Fifty-nine (54.6%) patients had reached minimal manifestation (MM) status; 32 (29.6%) having a status of MM-1 and 27 (25%) a status of MM-3. CONCLUSIONS The presence of AchR Abs (p = 0.034) and an abnormal SFEMG (p = 0.006) at onset as increased risk factors for the presence of ongoing signs necessitating medical treatment.
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Affiliation(s)
- Neşe Çelebisoy
- Department of Neurology, Ege University Medical School, 35100, Izmir, Turkey
| | - Asim Orujov
- Department of Neurology, Ege University Medical School, 35100, Izmir, Turkey
| | - Fidan Balayeva
- Department of Neurology, Ege University Medical School, 35100, Izmir, Turkey
| | | | - Ayşın Kısabay Ak
- Department of Neurology, Celal Bayar University Medical School, 45000, Manisa, Turkey.
| | - Figen Gökçay
- Department of Neurology, Ege University Medical School, 35100, Izmir, Turkey
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24
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Harada Y, Bettin M, Juel VC, Hobson-Webb LD, Raja SM, Sanders DB, Massey JM. Pregnancy in MuSK-positive myasthenia gravis: A single-center case series. Muscle Nerve 2023. [PMID: 37150596 DOI: 10.1002/mus.27839] [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: 08/19/2022] [Revised: 04/18/2023] [Accepted: 04/18/2023] [Indexed: 05/09/2023]
Abstract
INTRODUCTION/AIMS Myasthenia gravis (MG) with muscle-specific tyrosine kinase (MuSK) antibodies (MMG) is predominantly seen in women of childbearing age. Our objective in this study was to describe the course of MMG during pregnancy and within 6 months postpartum, and to document any effect on fetal health. METHODS A retrospective review was performed of medical records of patients with MMG seen in the Duke Myasthenia Gravis Clinic from 2003 to 2022. MMG patients with onset of MMG symptoms before or during pregnancy as well as within 6 months postpartum were reviewed. RESULTS A total of 14 pregnancies in 10 patients were included in our study cohort. Initial MG symptoms developed during pregnancy or within 6 months postpartum in six patients. Four patients had two pregnancies, three of whom developed MG during their first pregnancy. In the patients diagnosed before pregnancy, MG symptoms increased in five of eight patients during pregnancy or postpartum. Four patients required rescue therapy with plasma exchange or intravenous immunoglobulin during pregnancy or postpartum. One patient had a cesarean section after prolonged labor due to failure of progression. There were no other complications of pregnancy or delivery, and all infants were healthy at delivery. DISCUSSION As in non-MuSK MG, women with MMG may also have worsening or may develop initial MG symptoms during pregnancy or within 6 months postpartum. More aggressive medical therapy may be required for pregnant patients with MMG. Further study is needed to identify the mechanism and risk of worsening of MMG during pregnancy or postpartum.
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Affiliation(s)
- Yohei Harada
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Margaret Bettin
- Division of Neurology, Centra Neurology, Lynchburg, Virginia, USA
| | - Vern C Juel
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Lisa D Hobson-Webb
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Shruti M Raja
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Donald B Sanders
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Janice M Massey
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
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25
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Gilhus NE. Myasthenia gravis, respiratory function, and respiratory tract disease. J Neurol 2023:10.1007/s00415-023-11733-y. [PMID: 37101094 PMCID: PMC10132430 DOI: 10.1007/s00415-023-11733-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/14/2023] [Accepted: 04/16/2023] [Indexed: 04/28/2023]
Abstract
Myasthenia gravis (MG) is characterized by muscle weakness caused by autoantibodies that bind to the postsynaptic membrane at the neuromuscular junction and impair acetylcholine receptor function. Weakness of respiratory muscles represents the most severe MG manifestation, and 10-15% of all patients experience an MG crisis with the need of mechanical ventilatory support at least once in their life. MG patients with respiratory muscle weakness need active immunosuppressive drug treatment long term, and they need regular specialist follow-up. Comorbidities affecting respiratory function need attention and optimal treatment. Respiratory tract infections can lead to MG exacerbations and precipitate an MG crisis. Intravenous immunoglobulin and plasma exchange are the core treatments for severe MG exacerbations. High-dose corticosteroids, complement inhibitors, and FcRn blockers represent fast-acting treatments that are effective in most MG patients. Neonatal myasthenia is a transient condition with muscle weakness in the newborn caused by mother's muscle antibodies. In rare cases, treatment of respiratory muscle weakness in the baby is required.
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Affiliation(s)
- Nils Erik Gilhus
- Department of Neurology, Haukeland University Hospital, 5021, Bergen, Norway.
- Department of Clinical Medicine, University of Bergen, Bergen, Norway.
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26
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Mori S, Suzuki S, Konishi T, Kawaguchi N, Kishi M, Kuwabara S, Ishizuchi K, Zhou H, Shibasaki F, Tsumoto H, Omura T, Miura Y, Mori S, Higashihara M, Murayama S, Shigemoto K. Proteolytic ectodomain shedding of muscle-specific tyrosine kinase in myasthenia gravis. Exp Neurol 2023; 361:114300. [PMID: 36525997 DOI: 10.1016/j.expneurol.2022.114300] [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: 07/12/2022] [Revised: 11/07/2022] [Accepted: 12/10/2022] [Indexed: 12/15/2022]
Abstract
Autoantibodies to muscle-specific tyrosine kinase (MuSK) proteins at the neuromuscular junction (NMJ) cause refractory generalized myasthenia gravis (MG) with dyspnea more frequently than other MG subtypes. However, the mechanisms via which MuSK, a membrane protein locally expressed on the NMJ of skeletal muscle, is supplied to the immune system as an autoantigen remains unknown. Here, we identified MuSK in both mouse and human serum, with the amount of MuSK dramatically increasing in mice with motor nerve denervation and in MG model mice. Peptide analysis by liquid chromatography-tandem-mass spectrometry (LC-MS/MS) confirmed the presence of MuSK in both human and mouse serum. Furthermore, some patients with MG have significantly higher amounts of MuSK in serum than healthy controls. Our results indicated that the secretion of MuSK proteins from muscles into the bloodstream was induced by ectodomain shedding triggered by neuromuscular junction failure. The results may explain why MuSK-MG is refractory to treatments and causes rapid muscle atrophy in some patients due to the denervation associated with Ab-induced disruption of neuromuscular transmission at the NMJ. Such discoveries pave the way for new MG treatments, and MuSK may be used as a biomarker for other neuromuscular diseases in preclinical studies, clinical diagnostics, therapeutics, and drug discovery.
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Affiliation(s)
- Shuuichi Mori
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan
| | - Shigeaki Suzuki
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | | | - Naoki Kawaguchi
- Dowa Institute of Clinical Neuroscience, Neurology Clinic Chiba, Chiba, Japan
| | - Masahiko Kishi
- Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan
| | - Satoshi Kuwabara
- Department of Neurology, Chiba University School of Medicine, Chiba, Japan
| | - Kei Ishizuchi
- Department of Neurology, Keio University School of Medicine, Tokyo, Japan
| | - Heying Zhou
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan
| | - Futoshi Shibasaki
- Department of Genome Medicine, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hiroki Tsumoto
- Research Team for Mechanism of Aging, TMIG, Tokyo, Japan
| | - Takuya Omura
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan
| | - Yuri Miura
- Research Team for Mechanism of Aging, TMIG, Tokyo, Japan
| | - Seijiro Mori
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan
| | - Mana Higashihara
- Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo (TMGHIG), Japan
| | | | - Kazuhiro Shigemoto
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology (TMIG), Tokyo, Japan.
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27
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Vinciguerra C, Iacono S, Bevilacqua L, Landolfi A, Piscosquito G, Ginanneschi F, Schirò G, Di Stefano V, Brighina F, Barone P, Balistreri CR. Sex differences in neuromuscular disorders. Mech Ageing Dev 2023; 211:111793. [PMID: 36806604 DOI: 10.1016/j.mad.2023.111793] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 02/19/2023]
Abstract
The prevalence, onset, pathophysiology, and clinical course of many neuromuscular disorders (NMDs) may significantly differ between males and females. Some NMDs are more frequently observed in females, and characterized to show a higher grade of severity during or after the pregnancy. Meanwhile, others tend to have an earlier onset in males and exhibit a more variable progression. Prevalently, sex differences in NMDs have a familiar character given from genetic inheritance. However, they may also influence clinical presentation and disease severity of acquired NMD forms, and are represented by both hormonal and genetic factors. Consequently, to shed light on the distinctive role of biological factors in the different clinical phenotypes, we summarize in this review the sex related differences and their distinctive biological roles emerging from the current literature in both acquired and inherited NMDs.
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Affiliation(s)
- Claudia Vinciguerra
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy.
| | - Salvatore Iacono
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Liliana Bevilacqua
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Annamaria Landolfi
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Giuseppe Piscosquito
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Federica Ginanneschi
- Department of Medical, Surgical and Neurological Sciences, University of Siena, 53100 Siena, Italy
| | - Giuseppe Schirò
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Vincenzo Di Stefano
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Filippo Brighina
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Paolo Barone
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Carmela Rita Balistreri
- Cellular and Molecular Laboratory, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90134 Palermo
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28
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Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune disease where muscle antibodies form against the acetylcholine receptor (AChR), MuSK, or LRP4 at the neuromuscular junction leading to weakness. Patients worry about consequences for pregnancy, giving birth, nursing, and child outcome. AREAS COVERED This review lists the pharmacological treatments for MG in the reproductive age and gives recommendations. Consequences for pregnancy, giving birth, breastfeeding, and child outcome are discussed. EXPERT OPINION Pyridostigmine, corticosteroids in low doses, and azathioprine are regarded as safe during pregnancy and should be continued. Mycophenolate mofetil, methotrexate, and cyclophosphamide should not be used in reproductive age. Rituximab should not be given during pregnancy. Other monoclonal IgG antibodies such as eculizumab and efgartigimod should be given only when regarded strictly necessary to avoid long-term and severe incapacity. Intravenous and subcutaneous immunoglobulin and plasma exchange are safe treatments during pregnancy and are recommended for exacerbations with moderate or severe generalized weakness. Most MG women have spontaneous vaginal deliveries. Indications for Cesarean section are obstetrical and similar to non-MG women. Neonatal myasthenia manifests as a transient weakness caused by the mother's IgG muscle antibodies and affects 10% of the babies. MG women should be supported in their wish to have children.
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Affiliation(s)
- Nils Erik Gilhus
- Department of Neurology, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Medicine, University of Bergen, Bergen, Norway
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29
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Kwon YN, Woodhall M, Sung JJ, Kim KK, Lim YM, Kim H, Kim JE, Baek SH, Kim BJ, Park JS, Seok HY, Kim DS, Kwon O, Park KH, Sohn E, Bae JS, Yoon BN, Kim NH, Ahn SW, Choi K, Oh J, Park HJ, Shin KJ, Lee S, Park J, Kim SH, Seok JI, Bae DW, An JY, Joo IS, Choi SJ, Nam TS, Kim S, Park KJ, Kwon KH, Waters P, Hong YH. Clinical pitfalls and serological diagnostics of MuSK myasthenia gravis. J Neurol 2023; 270:1478-1486. [PMID: 36396811 PMCID: PMC9971039 DOI: 10.1007/s00415-022-11458-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/22/2022] [Accepted: 10/25/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUND We aimed to evaluate the diagnostic accuracy of enzyme-linked immunosorbent assay (ELISA) for anti-muscle specific tyrosine kinase (MuSK) antibody (Ab) in a large cohort of anti-acetylcholine receptor (AChR) Ab-negative generalized myasthenia gravis (MG), and also to investigate clinical contexts for the diagnosis of MuSK MG. METHODS A retrospective study of 160 patients with a clinical suspicion of AChR Ab-negative generalized MG was performed. The serum samples were tested for anti-clustered AChR Ab by cell-based assay (CBA), anti-MuSK Ab by ELISA, CBA and/or radioimmunoprecipitation assay (RIPA). Clinical data were compared between anti-MuSK Ab-positive MG and double seronegative (AChR and MuSK) MG groups. RESULTS After excluding non-MG and clustered AChR Ab-positive patients, we identified 89 patients as a cohort of AChR Ab-negative generalized MG. Anti-MuSK Ab was positive by ELISA in 22 (24.7%) patients. While CBA identified five additional anti-MuSK Ab-positive patients, the results of ELISA were mostly consistent with CBA and RIPA with Cohen's kappa of 0.80 and 0.90, respectively (p < 0.001). The most frequent differential diagnosis was motor neuron disease particularly of bulbar onset which showed remarkably overlapping clinical and electrophysiological features with MuSK MG at presentation. CONCLUSION While confirming the highest sensitivity of CBA for detecting anti-MuSK Ab, our results highlight the clinical pitfalls in making a diagnosis of MuSK MG and may support a diagnostic utility of MuSK-ELISA in clinical practice.
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Affiliation(s)
- Young Nam Kwon
- Department of Neurology, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Republic of Korea
- Department of Neurology, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Mark Woodhall
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, Neuroimmunology Group, University of Oxford, John Radcliffe Hospital, Level 5, West Wing, Headley Way, Oxford, OX3 9DU, UK
| | - Jung-Joon Sung
- Department of Neurology, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Neurology, Seoul National University College of Medicine, Neuroscience Research Institute, Seoul National University Medical Research Council, 20 Boramae-Ro 5-Gil, Dongjak-Gu, Seoul, 07061, Republic of Korea
| | - Kwang-Kuk Kim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Young-Min Lim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Hyunjin Kim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jee-Eun Kim
- Department of Neurology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Seol-Hee Baek
- Department of Neurology, Korea University College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - Byung-Jo Kim
- Department of Neurology, Korea University College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - Jin-Sung Park
- Department of Neurology, School of Medicine, Kyungpook National University, Kyungpook National University Chilgok Hospital, Daegu, Republic of Korea
| | - Hung Youl Seok
- Department of Neurology, Dongsan Hospital, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Dae-Seong Kim
- Department of Neurology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Ohyun Kwon
- Department of Neurology, Uijeongbu Eulji Medical Center, Eulji University School of Medicine, Uijeongbu, Republic of Korea
| | - Kee Hong Park
- Department of Neurology, Seoul Medical Center, Seoul, Republic of Korea
| | - Eunhee Sohn
- Department of Neurology, Chungnam National University College of Medicine, Chungnam National University Hospital, Daejeon, Republic of Korea
| | - Jong Seok Bae
- Department of Neurology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea
| | - Byung-Nam Yoon
- Department of Neurology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Republic of Korea
| | - Nam-Hee Kim
- Department of Neurology, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
| | - Suk-Won Ahn
- Department of Neurology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Kyomin Choi
- Department of Neurology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Jeeyoung Oh
- Department of Neurology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Hyung Jun Park
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Kyong Jin Shin
- Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea
| | - Sanggon Lee
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Jinseok Park
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Seung Hyun Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Jung Im Seok
- Department of Neurology, School of Medicine, Catholic University of Daegu, Daegu, Republic of Korea
| | - Dae Woong Bae
- Department of Neurology, College of Medicine, St. Vincent Hospital, The Catholic University of Korea, Suwon, Republic of Korea
| | - Jae Young An
- Department of Neurology, College of Medicine, St. Vincent Hospital, The Catholic University of Korea, Suwon, Republic of Korea
| | - In Soo Joo
- Department of Neurology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Seok-Jin Choi
- Department of Neurology, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Tai-Seung Nam
- Department of Neurology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Sunyoung Kim
- Department of Neurology, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Ki-Jong Park
- Department of Neurology, College of Medicine, Gyeongsang National University, Gyeonsang Institute of Health Science, Jinju, Republic of Korea
| | - Ki-Han Kwon
- Department of Neurology, Hallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Republic of Korea
| | - Patrick Waters
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, Neuroimmunology Group, University of Oxford, John Radcliffe Hospital, Level 5, West Wing, Headley Way, Oxford, OX3 9DU, UK.
| | - Yoon-Ho Hong
- Department of Neurology, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Republic of Korea.
- Department of Neurology, Seoul National University College of Medicine, Neuroscience Research Institute, Seoul National University Medical Research Council, 20 Boramae-Ro 5-Gil, Dongjak-Gu, Seoul, 07061, Republic of Korea.
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30
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Abstract
Myasthenia gravis is an autoimmune disorder caused by antibodies against elements in the postsynaptic membrane at the neuromuscular junction, which leads to muscle weakness. Congenital myasthenic syndromes are rare and caused by mutations affecting pre- or postsynaptic function at the neuromuscular synapse and resulting in muscle weakness. MG has a prevalence of 150-250 and an annual incidence of 8-10 individuals per million. The majority has disease onset after age 50 years. Juvenile MG with onset in early childhood is more common in East Asia. MG is subgrouped according to type of pathogenic autoantibodies, age of onset, thymus pathology, and generalization of muscle weakness. More than 80% have antibodies against the acetylcholine receptor. The remaining have antibodies against MuSK, LRP4, or postsynaptic membrane antigens not yet identified. A thymoma is present in 10% of MG patients, and more than one-third of thymoma patients develop MG as a paraneoplastic condition. Immunosuppressive drug therapy, thymectomy, and symptomatic drug therapy with acetylcholine esterase inhibitors represent cornerstones in the treatment. The prognosis is good, with the majority of patients having mild or moderate symptoms only. Most congenital myasthenic syndromes are due to dysfunction in the postsynaptic membrane. Symptom debut is in early life. Symptomatic drug treatment has sometimes a positive effect.
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Affiliation(s)
- Nils Erik Gilhus
- Department of Neurology, Haukeland University Hospital and Department of Clinical Medicine, University of Bergen, Bergen, Norway.
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31
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Shah SMI, Yasmin F, Memon RS, Jatoi NN, Savul IS, Kazmi S, Monawwer SA, Zafar MDB, Asghar MS, Tahir MJ, Lee KY. COVID-19 and myasthenia gravis: A review of neurological implications of the SARS-COV-2. Brain Behav 2022; 12:e2789. [PMID: 36306401 PMCID: PMC9759145 DOI: 10.1002/brb3.2789] [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] [Received: 04/22/2022] [Revised: 09/10/2022] [Accepted: 09/24/2022] [Indexed: 11/11/2022] Open
Abstract
INTRODUCTION This review highlights the potential mechanisms of neuromuscular manifestation of COVID-19, especially myasthenia gravis (MG). METHODS An extensive literature search was conducted by two independent investigators using PubMed/MEDLINE and Google Scholar from its inception to December 2020. RESULTS Exacerbations of clinical symptoms in patients of MG who were treated with some commonly used COVID-19 drugs has been reported, with updated recommendations of management of symptoms of neuromuscular disorders. Severe acute respiratory syndrome coronavirus 2 can induce the immune response to trigger autoimmune neurological disorders. CONCLUSIONS Further clinical studies are warranted to indicate and rather confirm if MG in the setting of COVID-19 can pre-existent subclinically or develop as a new-onset disease.
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Affiliation(s)
| | - Farah Yasmin
- Department of Internal Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Roha Saeed Memon
- Department of Internal Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Nadia Nazir Jatoi
- Department of Internal Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Ilma Saleh Savul
- Department of Internal Medicine, St. Joseph Medical Center, Houston, Texas, USA
| | - Sana Kazmi
- Department of Internal Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | | | - Muhammad Daim Bin Zafar
- Department of Internal Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | | | | | - Ka Yiu Lee
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
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Investigation of comorbid autoimmune diseases in women with autoimmune bullous diseases: An interplay of autoimmunity and practical implications. Int J Womens Dermatol 2022; 8:e053. [PMID: 36225612 PMCID: PMC9543088 DOI: 10.1097/jw9.0000000000000053] [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: 04/03/2022] [Accepted: 08/18/2022] [Indexed: 11/25/2022] Open
Abstract
Autoimmune bullous diseases are a group of skin disorders resulting from an autoimmune reaction against intercellular adhesion molecules or components of the basement membrane of skin and mucosa. Autoimmune disorders often occur in patients with a history of another autoimmune disease and most autoimmune diseases have a striking female predominance. In this review, we aim to analyze the different associations of autoimmune bullous diseases with other autoimmune diseases and highlight the distinctiveness of the female gender in these associations.
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MuSK-Myasthenia Gravis Unmasked by Hydroxychloroquine. Case Rep Med 2022; 2022:4802538. [PMID: 35874444 PMCID: PMC9307397 DOI: 10.1155/2022/4802538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 06/13/2022] [Accepted: 06/17/2022] [Indexed: 11/29/2022] Open
Abstract
Introduction Muscle-specific tyrosine kinase (MuSK) antibody positive myasthenia gravis (MuSK-MG) is a rare clinical disorder, and diagnosing it can be challenging. Most of the patients present with predominant facial, oculo-bulbar, and neck muscle weakness along with respiratory muscle involvement. Such a presentation can be mistaken for bulbar onset motor neuron disease or as one of the rare oculopharyngeal myopathies. Case Report. We present a young female patient, who reported to us with neck muscle weakness, ocular and bulbar muscle paralysis, and breathing difficulty. She had been healthy till she was prescribed hydroxychloroquine (HCQ) tablets (400 mg per day) for a malar rash. By the end of the second week after commencing the HCQ therapy, she developed the muscle weakness. Her symptoms began to regress after stopping HCQ and starting steroids, pyridostigmine, and, subsequently, azathioprine. She was negative for anticholinesterase receptor antibodies (AChR-Ab) but was positive for MuSK antibodies (MuSK-Ab). Conclusion This report proves that MuSK-MG can also be unmasked by HCQ administration. Awareness of drug-induced/-unmasked MG is important, as failure to do so may result in a severe morbidity and a fatal outcome. The offending drug has to be promptly discontinued, and appropriate treatment should be instituted.
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PARMAKSIZ G. Tedavisi zor nefrotik sendromlu çocuklarda rituksimab tedavisi. CUKUROVA MEDICAL JOURNAL 2022. [DOI: 10.17826/cumj.1038641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Amaç: Rituksimab (RTX), tedavisi zor nefrotik sendromlu (sık tekrarlayan, steroide bağımlı ve steroide dirençli) hastalar için kurtarma tedavisi olarak önerilmektedir. Amacımız zor nefrotik sendromlu çocuklarda RTX tedavisinin etkinliğini ve uzun dönem sonuçlarını değerlendirmek ve deneyimlerimizi paylaşmaktır.
Gereç ve Yöntem: RTX ile tedavi edilen zor nefrotik sendromlu çocukların tıbbi kayıtları geriye dönük olarak değerlendirildi. Oniki ayda nükssüz sağkalım oranı ve B hücre deplesyonun izlemi değerlendirildi.
Bulgular: Çalışmaya 8'i steroide bağımlı (SBNS), 6'sı sık tekrarlayan (STNS) ve 6'sı steroide dirençli nefrotik sendromlu (SDNS) 20 çocuk dahil edildi. RTX tedavisi alan STNS/SBNS hastalarının tedavi öncesi ve sonrası 1 yıllık ortalama nüks sayısı karşılaştırıldı. Ortalama nüks sayısı 2 (1-4)’den 0 (0-1) kez/yıla geriledi. RTX tedavisi sonrası ortalama takip süresi 23 ay (12-59) ve 8 hastada nüks gelişti. RTX tedavisi sonrası nüks eden 5 hastaya, tekrarlayan dozlarda RTX uygulandı. Bu hastalarda, CD19+B hücreleri remisyon sırasında yeniden ortaya çıkarken, hafıza B hücrelerinin deplesyonu devam etti.
Sonuç: RTX tedavisi, STNS/SBNS hastalarında remisyon süresini uzattı, ancak SDNS hastalarında etkisiz kaldı. Bu hastalarda remisyonun idamesi için RTX dozunun tekrarlanabileceği ve tekrarlama dozlarının zamanlamasında en iyi hafıza B hücre sayısının yardımcı olabileceği saptandı.
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Risk for generalization in ocular onset myasthenia gravis: experience from a neuro-ophthalmology clinic. Acta Neurol Belg 2022; 122:337-344. [PMID: 33544334 DOI: 10.1007/s13760-020-01582-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/17/2020] [Indexed: 01/13/2023]
Abstract
Conversion to generalized myasthenia gravis (GMG) within the first 2 years has been reported in 18-85% of patients with ocular myasthenia gravis (OMG). The aim of the study was to investigate the risk factors for generalization in patients with OMG admitted to a neuro-ophthalmology clinic and to determine if there were differences between patients with GMG with predominant bulbar (GMG-B) or extremity muscle (GMG-E) involvement according to the 6th and 24th-month Myasthenia Gravis Foundation of America classification ranks. Patients with OMG who were followed-up for at least 24 months were retrospectively analyzed. Demographic, clinical, laboratory features and treatment strategies that can be associated with generalization and time to generalization were evaluated. Of the 139 patients with OMG, 54 (39%) showed generalization with a mean time of 10.3 (range 2-24) months. GMG-B and GMG-E were diagnosed in 31 (22.3%) and 23 patients (16.5%), respectively. Seropositivity for acetylcholine receptor and muscle-specific tyrosine kinase antibodies, abnormal single-fiber electromyography (SFEMG), and the presence of thymic abnormalities (thymoma and hyperplasia) were factors associated with generalization on multivariate analysis without a significant difference between the GMG-B and GMG-E groups. In addition, an abnormal repetitive nerve stimulation test was related to a shortened time to generalization. Bilateral ptosis at onset was found as a risk factor for generalization. In a neuro-ophthalmology clinic, bilateral ptosis as an initial feature of OMG must be approached cautiously because it may be the first sign of impending GMG.
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Li Y, Yang S, Dong X, Li Z, Peng Y, Jin W, Chen D, Zhou R, Jiang F, Yan C, Yang H. Factors affecting minimal manifestation status induction in myasthenia gravis. Ther Adv Neurol Disord 2022; 15:17562864221080520. [PMID: 35371293 PMCID: PMC8968991 DOI: 10.1177/17562864221080520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 01/25/2022] [Indexed: 11/20/2022] Open
Abstract
Background: Minimal manifestation status (MMS) is an important landmark in the treatment of myasthenia gravis (MG), and predictors of MMS induction have rarely been identified in previous studies. Objective: The objective of this study is to evaluate the clinical factors associated with MMS induction among patients with MG. Design: This two-step retrospective cohort study with a single center investigated the factors that may be associated with MMS induction and retested these predictors in a test cohort. Methods: A total of 388 diagnosed MG patients who visited Xiangya Hospital between 1 July 2015 and 1 July 2019 were involved. We performed detailed chart reviews and recorded all cases achieving MMS. Demographics and clinical characteristics were also collected and their relationships to achieving MMS were investigated. Results: MMS was achieved in 124 patients (50.2%), and the median time to achieve MMS was 26 months. Several factors were found to be associated with MMS induction in exploring cohort, including muscle-specific tyrosine-protein kinase receptor (MuSK) antibody positivity (adjusted hazard ratio, HR = 4.333, 95% confidence interval, CI: 1.862–10.082), isolated ocular involvement (adjusted HR = 1.95, 95% CI: 1.284–2.961), and low baseline quantitative myasthenia gravis score (QMG score; adjusted HR = 2.022, 95% CI: 1.086–3.764). These factors were then retested in the test cohort. Isolated ocular involvement or low baseline QMG scores were factors found to be beneficial for MMS induction were confirmed. Conclusion: Isolated ocular involvement and low baseline QMG score are predictors of MMS induction in MG patients.
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Affiliation(s)
- Yi Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Shumei Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Xiaohua Dong
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Zhibin Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Yuyao Peng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Wanlin Jin
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Di Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Ran Zhou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Fei Jiang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Chengkai Yan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, P.R. China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha 410008, Hunan, P.R. China
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Koneczny I, Tzartos J, Mané-Damas M, Yilmaz V, Huijbers MG, Lazaridis K, Höftberger R, Tüzün E, Martinez-Martinez P, Tzartos S, Leypoldt F. IgG4 Autoantibodies in Organ-Specific Autoimmunopathies: Reviewing Class Switching, Antibody-Producing Cells, and Specific Immunotherapies. Front Immunol 2022; 13:834342. [PMID: 35401530 PMCID: PMC8986991 DOI: 10.3389/fimmu.2022.834342] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/28/2022] [Indexed: 12/24/2022] Open
Abstract
Organ-specific autoimmunity is often characterized by autoantibodies targeting proteins expressed in the affected tissue. A subgroup of autoimmunopathies has recently emerged that is characterized by predominant autoantibodies of the IgG4 subclass (IgG4-autoimmune diseases; IgG4-AID). This group includes pemphigus vulgaris, thrombotic thrombocytopenic purpura, subtypes of autoimmune encephalitis, inflammatory neuropathies, myasthenia gravis and membranous nephropathy. Although the associated autoantibodies target specific antigens in different organs and thus cause diverse syndromes and diseases, they share surprising similarities in genetic predisposition, disease mechanisms, clinical course and response to therapies. IgG4-AID appear to be distinct from another group of rare immune diseases associated with IgG4, which are the IgG4-related diseases (IgG4-RLD), such as IgG4-related which have distinct clinical and serological properties and are not characterized by antigen-specific IgG4. Importantly, IgG4-AID differ significantly from diseases associated with IgG1 autoantibodies targeting the same organ. This may be due to the unique functional characteristics of IgG4 autoantibodies (e.g. anti-inflammatory and functionally monovalent) that affect how the antibodies cause disease, and the differential response to immunotherapies of the IgG4 producing B cells/plasmablasts. These clinical and pathophysiological clues give important insight in the immunopathogenesis of IgG4-AID. Understanding IgG4 immunobiology is a key step towards the development of novel, IgG4 specific treatments. In this review we therefore summarize current knowledge on IgG4 regulation, the relevance of class switching in the context of health and disease, describe the cellular mechanisms involved in IgG4 production and provide an overview of treatment responses in IgG4-AID.
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Affiliation(s)
- Inga Koneczny
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
- *Correspondence: Inga Koneczny,
| | - John Tzartos
- Neuroimmunology, Tzartos NeuroDiagnostics, Athens, Greece
- 2nd Department of Neurology, “Attikon” University Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Marina Mané-Damas
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands
| | - Vuslat Yilmaz
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Maartje G. Huijbers
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, Netherlands
| | - Konstantinos Lazaridis
- Department of Immunology, Laboratory of Immunology, Hellenic Pasteur Institute, Athens, Greece
| | - Romana Höftberger
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Erdem Tüzün
- Department of Neuroscience, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Pilar Martinez-Martinez
- Research Group Neuroinflammation and Autoimmunity, Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands
| | - Socrates Tzartos
- Neuroimmunology, Tzartos NeuroDiagnostics, Athens, Greece
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
| | - Frank Leypoldt
- Neuroimmunology, Institute of Clinical Chemistry and Department of Neurology, UKSH Kiel/Lübeck, Kiel University, Kiel, Germany
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Huang Q, Li F, Zhao S. Spotlight on MuSK positive myasthenia gravis: clinical characteristics, treatment and outcomes. BMC Neurol 2022; 22:73. [PMID: 35246057 PMCID: PMC8895578 DOI: 10.1186/s12883-022-02593-6] [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: 08/28/2021] [Accepted: 02/16/2022] [Indexed: 11/10/2022] Open
Abstract
Background To investigate the clinical characteristics, treatments and outcomes of patients with myasthenia gravis with antibodies to muscle-specific tyrosine kinase (MuSK-MG). Methods We retrospectively reviewed the cases of 21 patients with confirmed MuSK-MG between January 2012 and January 2020 in our centre. Detailed clinical data and long-term follow-up information were summarized. Results Females (17/21, 81%) predominated among these MuSK-MG patients, and the mean age of onset in this group was 51.86 ± 16.16 years. MuSK-MG patients were divided into three subgroups according to the symptoms of muscle weakness at onset: ocular myasthenia gravis (OMG, 47.6%), bulbar myasthenia gravis (BMG, 42.9%), and generalized myasthenia gravis (GMG, 9.5%). The mean progression time from symptom onset to other muscle group involvement in OMG patients was 4.38 ± 2.54 months. Pyridostigmine bromide was adopted in 81.0% of patients, and 90.5% of patients received corticosteroids. Compared to usage in hospitals, the median daily dose of corticosteroids decreased significantly at the last follow-up. A total of 85.7% of patients received a long-term follow-up, with an average time of 1202.17 ± 976.73 days. At the end of the follow-up period, 4.8% of patients had achieved complete stable remission, 42.9% of patients had minimal manifestations, 19.0% had improved, the condition of 4.8% of patients remained unchanged, and 9.5% of patients died. Conclusion Female patients were more prevalent in this study, and MuSK-MG patients rapidly progressed to a generalized state. Although approximately 50% of MuSK-MG patients can achieve a favourable outcome with conventional immunosuppressants, complete stable remission is rare, and approximately 15% respond poorly. More effective medications should be explored in these patients. Supplementary Information The online version contains supplementary material available at 10.1186/s12883-022-02593-6.
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Affiliation(s)
- Qi Huang
- Department of Thoracic Surgery, The First Affiliated Hospital of Zhengzhou University, 1 Jianshe East Road, Zhengzhou, 450003, Henan, China
| | - Feng Li
- Department of Thoracic Surgery, The First Affiliated Hospital of Zhengzhou University, 1 Jianshe East Road, Zhengzhou, 450003, Henan, China
| | - Song Zhao
- Department of Thoracic Surgery, The First Affiliated Hospital of Zhengzhou University, 1 Jianshe East Road, Zhengzhou, 450003, Henan, China.
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Hiew FL, Thit WM, Alexander M, Thirugnanam U, Siritho S, Tan K, Mya Aye SM, Ohnmar O, Estiasari R, Yassin N, Pasco PM, Keosodsay SS, Trong Nghia HT, Islam MDB, Wong SK, Lee S, Chhabra A, Viswanathan S. Consensus recommendation on the use of therapeutic plasma exchange for adult neurological diseases in Southeast Asia from the Southeast Asia therapeutic plasma exchange consortium. J Cent Nerv Syst Dis 2022; 13:11795735211057314. [PMID: 35173510 PMCID: PMC8842418 DOI: 10.1177/11795735211057314] [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: 05/06/2021] [Accepted: 10/12/2021] [Indexed: 11/30/2022] Open
Abstract
Therapeutic plasma exchange (TPE) is an effective and affordable treatment option in most parts of Southeast Asia (SEA). In 2018, the SEA TPE Consortium (SEATPEC) was established, consisting of regional neurologists working to improve outcome of various autoimmune neurological diseases. We proposed an immunotherapeutic guideline prioritizing TPE for this region. We reviewed disease burden, evidence-based treatment options, and major guidelines for common autoimmune neurological disorders seen in SEA. A modified treatment algorithm based on consensus agreement by key-opinion leaders was proposed. Autoimmune antibody diagnostic testing through collaboration with accredited laboratories was established. Choice of first-line immunotherapies (IVIg/corticosteroid/TPE) is based on available evidence, clinicians’ experience, contraindications, local availability, and affordability. TPE could be chosen as first-line therapy for GBS, CIDP, MG (acute/short term), IgG, A paraproteinemic neuropathy, and NMDAR encephalitis. Treatment is stopped for acute monophasic conditions such as GBS and ADEM following satisfactory outcome. For chronic immune disorders, a therapy taper or long-term maintenance therapy is recommended depending on the defined clinical state. TPE as second-line treatment is indicated for IVIg or corticosteroids refractory cases of ADEM, NMOSD (acute), MG, and NMDAR/LGI1/CASPR2/Hashimoto’s encephalitis. With better diagnosis, treatment initiation with TPE is a sustainable and effective immunotherapy for autoimmune neurological diseases in SEA.
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Affiliation(s)
- Fu Liong Hiew
- Department of Neurology, Kuala Lumpur Hospital, Kuala Lumpur, Malaysia
- Dr Fu Liong Hiew, Physician and Neurologist, Department of Neurology, Kuala Lumpur Hospital, Kuala Lumpur, Malaysia Jalan Pahang, Wilayah Persekutuan Kuala Lumpur 50586, Malaysia.
| | - Win Min Thit
- University of Medicine 1, Yangon, Myanmar
- Yangon General Hospital/University of Medicine 1, Yangon, Myanmar
| | - Mathew Alexander
- Brunei Neuroscience Stroke and Rehabilitation Centre, Pantai Jerudong Specialist Centre, Brunei Darussalam
| | | | - Sasitorn Siritho
- Division of Neurology, Faculty of Medicine, Siriraj Hospital, Bumrungrad International Hospital, Bangkok, Thailand
| | - Kevin Tan
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
| | | | - Ohnmar Ohnmar
- University of Medicine 1, Yangon, Myanmar
- Yangon General Hospital/University of Medicine 1, Yangon, Myanmar
| | - Riwanti Estiasari
- Department of Neurology, Cipto Mangunkusumo Hospital/Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | | | | | | | | | - MD Badrul Islam
- Laboratory Sciences and Services Division (LSSD), The International Centre for Diarrhoeal Disease, Dhaka, Bangladesh
| | - Sing Keat Wong
- Department of Neurology, Kuala Lumpur Hospital, Kuala Lumpur, Malaysia
| | - Shirley Lee
- Department of Neurology, Kuala Lumpur Hospital, Kuala Lumpur, Malaysia
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Huijbers MG, Marx A, Plomp JJ, Le Panse R, Phillips WD. Advances in the understanding of disease mechanisms of autoimmune neuromuscular junction disorders. Lancet Neurol 2022; 21:163-175. [DOI: 10.1016/s1474-4422(21)00357-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/15/2021] [Accepted: 10/06/2021] [Indexed: 01/19/2023]
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Meng X, Zeng Z, Wang Y, Guo S, Wang C, Wang B, Guo S. Efficacy and Safety of Low-Dose Rituximab in Anti-MuSK Myasthenia Gravis Patients: A Retrospective Study. Neuropsychiatr Dis Treat 2022; 18:953-964. [PMID: 35535211 PMCID: PMC9078430 DOI: 10.2147/ndt.s358851] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 04/21/2022] [Indexed: 01/19/2023] Open
Abstract
PURPOSE To evaluate the efficacy and safety of low dosages of rituximab (RTX) in the treatment of MuSK-antibody-positive MG patients. PATIENTS AND METHODS We retrospectively analyzed the data of MuSK-antibody-positive MG patients who were treated with low dosages of RTX from January 2018 to October 2021. The long-term treatment response to RTX was assessed by Myasthenia Gravis Foundation of America (MGFA) post-interventional status (PIS), Myasthenia Gravis Status and Treatment Intensity (MGSTI), dosage of steroid, MG-related activities of daily living (MG-ADL) and myasthenic muscle score (MMS) at the end of follow-up. RESULTS Clinical improvement was observed in all eight patients with follow-up for 8 to 29 months after treatment. At the last visit, complete stable remission had been achieved in one patient, pharmacologic remission in three patients, minimal manifestations status in three patients and improved in one patient based on the MGFA-PIS criteria. MGSTI level 2 or better had been reached in six (75%) patients at the last visit. The steroid dosage decreased from 60 mg at baseline to 15 mg at the last follow-up (p = 0.011). The average MG-ADL score decreased from 11 (range 7 to 15) to 0 (range 0 to 3; p = 0.011), and the MMS improved from 38.5 (range 24 to 60) to 100 (range 90 to 100; p = 0.012). These differences were all statistically significant. During RTX treatment and subsequent follow-up, 1 patient reported minor post-infusion malaise. CONCLUSION Low-dose RTX is effective and safe for treating anti-MuSK antibody positive MG patients. A long-term response is observed after treatment. Larger prospective studies are required to provide further evidence.
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Affiliation(s)
- Xin Meng
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Ziling Zeng
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Yunda Wang
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Shuai Guo
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Chunjuan Wang
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Baojie Wang
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Shougang Guo
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China.,Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
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Park G, Kesserwani H. Seropositive Muscle-Specific Tyrosine Kinase Myasthenia Gravis Presenting as a Late-Onset Isolated Sixth Nerve Palsy: A Case Report and a Brief Review of Subtypes of Myasthenia Gravis. Cureus 2021; 13:e19701. [PMID: 34934570 PMCID: PMC8684330 DOI: 10.7759/cureus.19701] [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] [Accepted: 11/18/2021] [Indexed: 11/30/2022] Open
Abstract
Autoimmune myasthenia gravis (MG) is a well-characterized post-synaptic disorder of neuromuscular transmission. Immunologically, there is complement activation with autoantibodies binding to the acetylcholine receptor (AChR), leading to cross-linking and internalization of the receptor. The diminished functional clustering leads to impaired folding of the post-synaptic membrane. The antibodies generated by the autoimmune process are directed at the various components of the post-synaptic membrane and its scaffolding, including the AChR, muscle-specific tyrosine kinase (MuSK), low-density lipoprotein receptor-related protein 4 (LRP4), and the other recently described epitopes including the extracellular membrane proteins agrin and collagen Q (ColQ). MuSK MG is phenotypically different from classic AChR-antibody-mediated MG by a more frequent presentation of bulbar weakness, less responsiveness to symptomatic therapy with acetylcholinesterase inhibitors, the absence of a thymoma, and a better therapeutic response to a cluster of differentiation (CD-20) B-cell therapy such as rituximab. The pleiotropic ocular findings of ocular MG include ptosis, fluctuating and variable involvement of cranial nerves III, IV, and VI, pseudo-internuclear ophthalmoplegia (INO), near-complete or complete ophthalmoplegia, and variable gaze palsies. To our knowledge, we present one of the very few reported cases of MuSK MG presenting as isolated sixth nerve palsy. The localization of a sixth nerve palsy with lateral rectus muscle weakness can be due to disease anywhere along its path from the abducens nucleus, coursing at the skull base through Dorello's canal, through the cavernous sinus, and along its path through the superior orbital fissure and into the orbits. A painless sixth nerve palsy should alert the clinician to MuSK-MG as we outline in this case report.
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Affiliation(s)
- Gyusik Park
- Neurology, University of Alabama at Birmingham School of Medicine, Birmingham, USA
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Bortone F, Scandiffio L, Cavalcante P, Mantegazza R, Bernasconi P. Epstein-Barr Virus in Myasthenia Gravis: Key Contributing Factor Linking Innate Immunity with B-Cell-Mediated Autoimmunity. Infect Dis (Lond) 2021. [DOI: 10.5772/intechopen.93777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Epstein-Barr virus (EBV), a common human herpes virus latently infecting most of the world’s population with periodic reactivations, is the main environmental factor suspected to trigger and/or sustain autoimmunity by its ability to disrupt B-cell tolerance checkpoints. Myasthenia gravis (MG) is a prototypic autoimmune disorder, mostly caused by autoantibodies to acetylcholine receptor (AChR) of the neuromuscular junction, which cause muscle weakness and fatigability. Most patients display hyperplastic thymus, characterized by ectopic germinal center formation, chronic inflammation, exacerbated Toll-like receptor activation, and abnormal B-cell activation. After an overview on MG clinical features and intra-thymic pathogenesis, in the present chapter, we describe our main findings on EBV presence in MG thymuses, including hyperplastic and thymoma thymuses, in relationship with innate immunity activation and data from other autoimmune conditions. Our overall data strongly indicate a critical contribution of EBV to innate immune dysregulation and sustained B-cell-mediated autoimmune response in the pathological thymus of MG patients.
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Beladakere Ramaswamy S, Singh S, Hooshmand S, Junsang C, Sweeney M, Govindarajan R. Current and Upcoming Treatment Modalities in Myasthenia Gravis. J Clin Neuromuscul Dis 2021; 23:75-99. [PMID: 34808650 DOI: 10.1097/cnd.0000000000000377] [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: 10/19/2022]
Abstract
ABSTRACT Myasthenia gravis (MG) is one of the extensively studied autoimmune disorder. There has been a dramatic increase in research to further understand molecular pathogenesis of MG and clinical trials for new drugs in MG treatment in the past decade. This review article is to consolidate the available information in simple terms with students, residents, and fellows as target audience for easy learning and help application of this knowledge to clinical practice.
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Su M, Zhao C, Luo S. Therapeutic potential of chimeric antigen receptor based therapies in autoimmune diseases. Autoimmun Rev 2021; 21:102931. [PMID: 34481941 DOI: 10.1016/j.autrev.2021.102931] [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] [Received: 07/22/2021] [Revised: 08/26/2021] [Accepted: 08/31/2021] [Indexed: 11/02/2022]
Abstract
Chimeric antigen receptor (CAR) based therapies have been adopted as an option for treating autoimmune diseases from the field of blood malignancies by targeting immune cells or rebalancing the pro-inflammatory milieu. Important questions still remained about the efficacy and safety regarding the dynamic and complex autoimmune pathological networks. We here reviewed the emerged developments in basic, translational, and clinical studies of the CAR based therapies in a wide spectrum of autoimmune diseases. The primary goal of the study is to provide some future perspectives on how to optimize the performance of CAR based therapies. The fundamental strategy is to engineer the recognition domains in CAR products for precisely targeting the components in the pro-inflammatory milieu. The second strategy is to incorporate multiple CARs in one carrier, or use fluorescein isothiocyanate (FITC)-CAR T cells for enhancing the therapeutic efficacy. In addition, we reviewed the preclinical evidence in disease-specific context. Overall, we aim to attract more attention in the field of developing future precision CAR based therapies to tailor medial decisions in autoimmune diseases.
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Affiliation(s)
- Manqiqige Su
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China.
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Modoni A, Mastrorosa A, Spagni G, Evoli A. Cholinergic hyperactivity in patients with myasthenia gravis with MuSK antibodies: A neurophysiological study. Clin Neurophysiol 2021; 132:1845-1849. [PMID: 34147009 DOI: 10.1016/j.clinph.2021.04.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/18/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Patients with myasthenia gravis associated with muscle-specific tyrosine kinase antibodies (MuSK-MG) often manifest signs of cholinergic hyperactivity with standard doses of acetylcholinesterase inhibitors (AChE-Is). Aim of the study was to investigate whether repetitive compound muscle action potential (R-CMAP), the neurophysiological correlate of cholinergic hyperactivity, was present in MuSK-MG irrespective of AChE-I treatment. METHODS Patients with confirmed diagnosis of MuSK-MG were consecutively enrolled during follow-up visits, from January 2019 to April 2020. All these subjects underwent the same neurophysiological protocol, including motor nerve conduction studies and repetitive nerve stimulation. In patients taking pyridostigmine, neurophysiological testing was performed at least 12 hours after the last dose. For comparison, the presence of R-CMAP was investigated in 20 consecutive acetylcholine receptor antibody positive myasthenia gravis (AChR-MG) patients. RESULTS We enrolled 25 MuSK-MG patients (20 females), aged 16-79 years at the study time, with disease duration ranging 0.6-48.8 years (median: 17.7 years). R-CMAP was detected in 12/25 (48%) MuSK-MG cases and in none of the AChR-MG controls (p = 0.0003). In the MuSK-MG population, a history of muscle cramps and fasciculations, during low-dose pyridostigmine therapy, was significantly more frequent in R-CMAP positive than in R-CMAP negative patients (100% vs 31%, p = 0.001). At the time of the study, the proportion of patients still symptomatic for MG was higher among R-CMAP positive cases (92% vs 23%, p = 0.0005). CONCLUSIONS Cholinergic hyperactivity is a relatively common finding in MuSK-MG patients, independent of AChE-I treatment, and may constitute an intrinsic feature of the disease. SIGNIFICANCE R-CMAP detection can represent a useful diagnostic clue for MuSK-MG and predicts poor tolerance to AChE-Is.
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Affiliation(s)
- Anna Modoni
- Unità Operativa Complessa di Neurologia, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Largo A. Gemelli, 8 - 00168 Rome, Italy
| | - Alessia Mastrorosa
- IRCCS Fondazione Don Gnocchi ONLUS, via di Scandicci 269, 50143, Florence, Italy
| | - Gregorio Spagni
- Dipartimento di Neuroscienze, Università Cattolica del Sacro Cuore, Largo F. Vito, 1 - 00168 Rome, Italy.
| | - Amelia Evoli
- Unità Operativa Complessa di Neurologia, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Largo A. Gemelli, 8 - 00168 Rome, Italy; Dipartimento di Neuroscienze, Università Cattolica del Sacro Cuore, Largo F. Vito, 1 - 00168 Rome, Italy
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47
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Jain R, Aulakh R. Pediatric Ocular Myasthenia Gravis: A Review. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0040-1721401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AbstractPediatric ocular myasthenia gravis (OMG) is difficult to diagnose and manage, owing to its rarity and low index of suspicion in the early stage of the disease. Also, many other conditions having similar presentation cause a further delay in diagnosis. In this review, we highlighted various pointers in history and described bedside clinical tests that can aid in its timely diagnosis. The antibody spectrum in myasthenia is ever increasing and includes anti-muscle specific kinase and low-density lipoprotein-receptor related protein 4 antibodies in addition to acetylcholine receptor antibodies besides many others. However, pediatric OMG patients often test negative for all three antibodies, making the diagnosis even more difficult in triple seronegative patients. Edrophonium and electrophysiological tests, which help in confirming myasthenia in adults, have a limited utility in diagnosing pediatric ocular myasthenia cases. Various practical difficulties are encountered like nonavailability of edrophonium, risk of bradycardia associated with neostigmine use and its lower sensitivity, noncooperative children, and limited technical expertise in performing electrophysiological tests in children. In this article, we described a pragmatic approach to diagnose pediatric OMG along with the important aspects of its management.
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Affiliation(s)
- Reena Jain
- Department of Pediatrics, Government Medical College & Hospital, Chandigarh, India
| | - Roosy Aulakh
- Department of Pediatrics, Government Medical College & Hospital, Chandigarh, India
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König N, Stetefeld HR, Dohmen C, Mergenthaler P, Kohler S, Schönenberger S, Bösel J, Lee DH, Gerner ST, Huttner HB, Schneider H, Reichmann H, Fuhrer H, Berger B, Zinke J, Alberty A, Kleiter I, Schneider-Gold C, Roth C, Dunkel J, Steinbrecher A, Thieme A, Schlachetzki F, Linker RA, Angstwurm K, Meisel A, Neumann B. MuSK-antibodies are associated with worse outcome in myasthenic crisis requiring mechanical ventilation. J Neurol 2021; 268:4824-4833. [PMID: 33970337 PMCID: PMC8563593 DOI: 10.1007/s00415-021-10603-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/01/2021] [Accepted: 05/05/2021] [Indexed: 10/24/2022]
Abstract
Myasthenic crisis (MC) is a life-threatening condition for patients with myasthenia gravis (MG). Muscle-specific kinase-antibodies (MuSK-ABs) are detected in ~ 6% of MG, but data on outcome of MuSK-MCs are still lacking. We made a subgroup analysis of patients who presented with MC with either acetylcholine-receptor-antibody positive MG (AchR-MG) or MuSK-MG between 2006 and 2015 in a retrospective German multicenter study. We identified 19 MuSK-AB associated MCs in 15 patients and 161 MCs in 144 patients with AchR-ABs only. In contrast to patients with AchR-AB, MuSK-AB patients were more often female (p = 0.05, OR = 2.74) and classified as Myasthenia Gravis Foundation of America-class IV before crisis (p = 0.04, OR = 3.25). MuSK-AB patients suffer more often from multiple chronic disease (p = 0.016, OR = 4.87) and were treated more invasively in terms of plasma exchanging therapies (not significant). The number of days of mechanical ventilation (MV) (43.0 ± 53.1 vs. 17.4 ± 18; p < 0.0001), days on an intensive care unit (ICU) (45.3 ± 49.5 vs. 21.2 ± 19.7; p < 0.0001), and hospital-length of stay (LOS) (55.9 ± 47.6 vs. 28.8 ± 20.9 days; p < 0.0001) were significantly increased in MuSK-MC. Remarkable is that these changes were mainly due to patients with MusK-ABs only, whereas patients' outcome with both antibodies was similar to AchR-MCs. Furthermore, our data showed a shortened duration of MV after treatment with plasma exchanging therapies compared to treatment with intravenous immunoglobulin in MuSK-MCs. We conclude that MuSK-AB-status is associated with a longer need of MV, ICU-LOS, and hospital-LOS in MC, and therefore recommend early initiation of a disease-specific therapy.
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Affiliation(s)
- Nicole König
- Department of Neurology, University of Regensburg, Bezirksklinikum Regensburg, Universitaetsstraße 84, 93051, Regensburg, Germany
| | | | - Christian Dohmen
- Department of Neurology, University of Cologne, Cologne, Germany.,Department of Neurology, LVR-Klinik Bonn, Bonn, Germany
| | - Philipp Mergenthaler
- NeuroCure Clinical Research Center, Charité, Universitätsmedizin Berlin, Berlin, Germany.,Departments of Neurology and Experimental Neurology, Center for Stroke Research Berlin, Charité, Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Siegfried Kohler
- NeuroCure Clinical Research Center, Charité, Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | | | - Julian Bösel
- Department of Neurology, Heidelberg University Hospital, Heidelberg, Germany.,Department of Neurology, Klinikum Kassel, Kassel, Germany
| | - De-Hyung Lee
- Department of Neurology, University of Regensburg, Bezirksklinikum Regensburg, Universitaetsstraße 84, 93051, Regensburg, Germany.,Department of Neurology, University Hospital Erlangen, Erlangen, Germany
| | - Stefan T Gerner
- Department of Neurology, University Hospital Erlangen, Erlangen, Germany
| | - Hagen B Huttner
- Department of Neurology, University Hospital Erlangen, Erlangen, Germany
| | - Hauke Schneider
- Department of Neurology, University Hospital, Technische Universität Dresden, Dresden, Germany.,Department of Neurology, University Hospital Augsburg, Augsburg, Germany
| | - Heinz Reichmann
- Department of Neurology, University Hospital, Technische Universität Dresden, Dresden, Germany
| | - Hannah Fuhrer
- Clinic of Neurology and Neurophysiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Benjamin Berger
- Clinic of Neurology and Neurophysiology, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jan Zinke
- Hans Berger Department of Neurology, Jena University Hospital, Jena, Germany
| | - Anke Alberty
- Department of Neurology, Kliniken Maria Hilf GmbH Moenchengladbach, Mönchengladbach, Germany
| | - Ingo Kleiter
- St. Josef-Hospital, Department of Neurology, Ruhr-University Bochum, Bochum, Germany.,Marianne-Strauß-Klinik, Behandlungszentrum Kempfenhausen Für Multiple Sklerose Kranke gGmbH, Berg, Germany
| | | | - Christian Roth
- Department of Neurology, DRK-Kliniken Nordhessen, Kassel, Germany.,Department of Neurology, Phillips University of Marburg, Marburg, Germany
| | - Juliane Dunkel
- Department of Neurology, DRK-Kliniken Nordhessen, Kassel, Germany
| | | | - Andrea Thieme
- Department of Neurology, Helios Klinikum Erfurt, Erfurt, Germany
| | - Felix Schlachetzki
- Department of Neurology, University of Regensburg, Bezirksklinikum Regensburg, Universitaetsstraße 84, 93051, Regensburg, Germany
| | - Ralf A Linker
- Department of Neurology, University of Regensburg, Bezirksklinikum Regensburg, Universitaetsstraße 84, 93051, Regensburg, Germany
| | - Klemens Angstwurm
- Department of Neurology, University of Regensburg, Bezirksklinikum Regensburg, Universitaetsstraße 84, 93051, Regensburg, Germany
| | - Andreas Meisel
- NeuroCure Clinical Research Center, Charité, Universitätsmedizin Berlin, Berlin, Germany.,Departments of Neurology and Experimental Neurology, Center for Stroke Research Berlin, Charité, Universitätsmedizin Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Bernhard Neumann
- Department of Neurology, University of Regensburg, Bezirksklinikum Regensburg, Universitaetsstraße 84, 93051, Regensburg, Germany.
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Fisher KS, Gill J, Todd HF, Yang MB, Lopez MA, Abid F, Lotze T, Shah VS. Pediatric Autoimmune Ocular Myasthenia Gravis: Evaluation of Presentation and Treatment Outcomes in a Large Cohort. Pediatr Neurol 2021; 118:12-19. [PMID: 33684630 DOI: 10.1016/j.pediatrneurol.2021.01.009] [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] [Received: 07/03/2020] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/01/2022]
Abstract
BACKGROUND In autoimmune myasthenia gravis (MG), autoantibodies target the neuromuscular junction. Ocular myasthenia gravis (OMG) is localized, affecting only extraocular and/or levator palpebrae muscles. OMG presents across all ages, varying in presentation, treatment modalities, and outcomes. Recently, there have been advances in MG/OMG treatment; their utilization and effectiveness are an important part of optimal disease management. METHODS We completed a retrospective chart review of children aged 18 years or younger with a confirmed diagnosis of OMG presenting from 2002 to 2019. RESULTS Forty-two patients were included with mean age at presentation of 8.5 years (2 to 18 years). Twenty-one patients (50%) had positive antibodies; 90% had acetylcholine receptor antibodies. Ten patients developed generalized symptoms with mean time to generalization of 13.6 months. Multiple logistic regression showed that older age of onset was a trend predictive factor (P = 0.054; odds ratio 1.17) for generalized disease. All patients were treated with pyridostigmine. Immunomodulating agents included steroids (15), mycophenolate mofetil (four), and intravenous immunoglobulin (one). Three patients underwent thymectomy. Twenty patients reached minimal manifestation status, and 12 achieved remission. Gender, race, and positive antibody status were not statistically significant predictors for advanced immunosuppressive therapy. CONCLUSIONS We summarize one of the largest cohorts of pediatric patients with OMG who have undergone up-to-date diagnostic and therapeutic regimens. The predictors of outcome and treatment pathway for OMG patients suggested by this report may be further elucidated by future prospective studies.
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Affiliation(s)
- Kristen S Fisher
- Department of Pediatric Neurology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas
| | - Jason Gill
- Department of Pediatric Neurology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas
| | | | - Michael B Yang
- Division of Pediatric Ophthalmology, Abrahamson Pediatric Eye Institute, Cincinnati, Ohio; Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Michael A Lopez
- Hess Pediatric Ophthalmology Specialist, St. Petersburg, Florida
| | - Farida Abid
- Department of Pediatric Neurology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas
| | - Timothy Lotze
- Department of Pediatric Neurology, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas
| | - Veeral S Shah
- Division of Pediatric Ophthalmology, Abrahamson Pediatric Eye Institute, Cincinnati, Ohio; Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; University of Cincinnati College of Medicine, Cincinnati, Ohio.
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50
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Assini A, Gandoglia I, Damato V, Rikani K, Evoli A, Del Sette M. Response to: "MuSK-positive myasthenia may be triggered not only by SARS-CoV-2". Eur J Neurol 2021; 28:e82-e83. [PMID: 33730439 PMCID: PMC8250645 DOI: 10.1111/ene.14827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 12/01/2022]
Affiliation(s)
| | | | - Valentina Damato
- Institute of Neurology, Fondazione Policlinico Universitario 'A. Gemelli' IRCCS, Roma, Italy.,Università Cattolica del Sacro Cuore, Roma, Italy
| | | | - Amelia Evoli
- Institute of Neurology, Fondazione Policlinico Universitario 'A. Gemelli' IRCCS, Roma, Italy.,Università Cattolica del Sacro Cuore, Roma, Italy
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