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Ricciardi R, Latini E, Guida M, Koneczny I, Lucchi M, Maestri M, De Rosa A, Vincent A. Acetylcholinesterase inhibitors are ineffective in MuSK-antibody positive myasthenia gravis: Results of a study on 202 patients. J Neurol Sci 2024; 461:123047. [PMID: 38759248 DOI: 10.1016/j.jns.2024.123047] [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: 02/06/2024] [Revised: 05/04/2024] [Accepted: 05/10/2024] [Indexed: 05/19/2024]
Abstract
BACKGROUND Myasthenia gravis (MG) with MuSK antibodies (MuSK-MG) represents a distinct subtype with different responses to treatments compared to patients with AChR antibodies, especially in terms of tolerance to acetylcholinesterase inhibitors (AChEI). However, AChEI are often used as first line symptomatic treatment in MuSK-MG, despite reports that they are poorly tolerated, seldom effective or even deleterious. METHODS We analyzed demographic, clinical and therapeutic responses and side-effects in the large cohort of 202 MuSK-MG patients cared for at the MG Clinic of Azienda Ospedaliero-Universitaria Pisana. RESULTS 165 patients had received AChEI at first evaluation. Only 7/165 patients (4.2%) reported an initial clinical benefit. Conversely, 76.9% of patients reported at least one side effect, most commonly neuromuscular hyperexcitability (68.4%), gastrointestinal (53.9%) and neurovegetative (35.8%) disturbances. 56 (33.9%) patients reported a concomitant worsening of muscle weakness and twelve patients (7.3%) suffered a cholinergic crisis. According to these patients, the severity of cholinergic side effects was greater at higher doses of AChEI, but side effects occurred regardless of the dose administered and ceased once the drug was discontinued. CONCLUSIONS This is the largest population of MuSK-MG patients reported for perceived responsiveness and tolerance to AChEI treatment. Our obervations strongly suggest avoiding this treatment in MuSK-MG.
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Affiliation(s)
- R Ricciardi
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Italy; CardioThoracic and Vascular Surgery Department, University of Pisa, Italy
| | - E Latini
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Italy.
| | - M Guida
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Italy
| | - I Koneczny
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, 1090 Vienna, Austria
| | - M Lucchi
- CardioThoracic and Vascular Surgery Department, University of Pisa, Italy
| | - M Maestri
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Italy
| | - A De Rosa
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Italy
| | - A Vincent
- Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
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Raza B, Dhamija A, Abbas G, Toker A. Robotic thymectomy for myasthenia gravis surgical techniques and outcomes. J Thorac Dis 2021; 13:6187-6194. [PMID: 34795970 PMCID: PMC8575861 DOI: 10.21037/jtd-2019-rts-10] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 09/10/2020] [Indexed: 11/30/2022]
Abstract
Myasthenia gravis (MG) is an autoimmune disorder in which antibodies are produced against post-synaptic acetylcholine receptors, thereby causing impairment of neuromuscular transmission. Diagnosis of MG is confirmed with the AChR antibody test and via an Electromyography. Although medical treatment with acetylcholinesterase inhibitors remains the main treatment of MG, in recent years thymectomy has become an integral part of the treatment algorithm. Numerous factors such as the Patient’s age, presence of AChR antibodies, or MuSK antibody, the severity of disease affect the decision of preforming the thymectomy. Historically thymectomy was preformed via sternotomy associated with significant morbidity. Advancement in the minimally invasive approaches to thymic resection has led to more acceptance of thymectomy in the management of MG. Among these approaches, robotic thymectomy is gaining popularity across the globe due to the unique advantages of the robotic platform like 3D visibility, enhanced dexterity, and wrist like articulating movements of instruments. This has led to less post-operative pain and morbidity; faster recovery and shorter hospital stay. Successful treatment of MG requires a multi-modality approach, which has led to the formation of MG teams in most academic centers, comprising of a specialist neurologist, intensivist, and thoracic surgeon. In this article, we describe the techniques and outcomes of the robotic thymectomy for MG.
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Affiliation(s)
| | - Ankit Dhamija
- Department of Cardiovascular and Thoracic Surgery, West Virginia University, Morgantown, WV, USA
| | - Ghulam Abbas
- Department of Cardiovascular and Thoracic Surgery, West Virginia University, Morgantown, WV, USA
| | - Alper Toker
- Department of Cardiovascular and Thoracic Surgery, West Virginia University, Morgantown, WV, USA
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Zingariello CD, Elder ME, Kang PB. Rituximab as Adjunct Maintenance Therapy for Refractory Juvenile Myasthenia Gravis. Pediatr Neurol 2020; 111:40-43. [PMID: 32951658 DOI: 10.1016/j.pediatrneurol.2020.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Juvenile myasthenia gravis is a pediatric autoimmune disorder of the neuromuscular junction associated with substantial morbidity, for which standard therapies are not always efficacious. The objective of our study was to assess the tolerability and efficacy of rituximab use in children with refractory juvenile myasthenia gravis. METHODS We conduced a retrospective cohort study at a single tertiary care referral center to evaluate children with juvenile myasthenia gravis who were treated with rituximab. The clinical status of these participants before and after initiation of rituximab therapy was measured, focusing on numbers of hospital admissions, numbers of immunomodulatory or immunosuppressive medications needed, and Myasthenia Gravis Foundation of America severity class. RESULTS Five children with juvenile myasthenia gravis were ascertained who received rituximab as part of their regimen, four of whom had elevated acetylcholine receptor antibodies and one of whom had elevated muscle-specific kinase antibodies. After initiation of rituximab therapy, all participants experienced reduced numbers of immunomodulatory medications during the follow-up period (mean 11.6 months). Four of the five subjects experienced fewer juvenile myasthenia gravis-related hospital admissions and reduced (improved) Myasthenia Gravis Foundation of America classes, with no subjects having moderate or severe symptoms following treatment with rituximab. No significant adverse events were recorded for any of the participants. CONCLUSION Rituximab was well-tolerated and efficacious in this juvenile myasthenia gravis cohort. The beneficial effect of rituximab was most pronounced in the one participant with muscle-specific kinase antibodies.
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Affiliation(s)
- Carla D Zingariello
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Melissa E Elder
- Division of Allergy, Immunology, and Rheumatology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida; Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida.
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4
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Abstract
Thirty to fifty percent of patients with acetylcholine receptor (AChR) antibody (Ab)-negative myasthenia gravis (MG) have Abs to muscle specific kinase (MuSK) and are referred to as having MuSK-MG. MuSK is a 100 kD single-pass post-synaptic transmembrane receptor tyrosine kinase crucial to the development and maintenance of the neuromuscular junction. The Abs in MuSK-MG are predominantly of the IgG4 immunoglobulin subclass. MuSK-MG differs from AChR-MG, in exhibiting more focal muscle involvement, including neck, shoulder, facial and bulbar-innervated muscles, as well as wasting of the involved muscles. MuSK-MG is highly associated with the HLA DR14-DQ5 haplotype and occurs predominantly in females with onset in the fourth decade of life. Some of the standard treatments of AChR-MG have been found to have limited effectiveness in MuSK-MG, including thymectomy and cholinesterase inhibitors. Therefore, current treatment involves immunosuppression, primarily by corticosteroids. In addition, patients respond especially well to B cell depletion agents, e.g., rituximab, with long-term remissions. Future treatments will likely derive from the ongoing analysis of the pathogenic mechanisms underlying this disease, including histologic and physiologic studies of the neuromuscular junction in patients as well as information derived from the development and study of animal models of the disease.
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Affiliation(s)
| | - David P. Richman
- Department of Neurology, University of California, Davis, Davis, CA, United States
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Lazaridis K, Baltatzidou V, Tektonidis N, Tzartos SJ. Antigen-specific immunoadsorption of MuSK autoantibodies as a treatment of MuSK-induced experimental autoimmune myasthenia gravis. J Neuroimmunol 2019; 339:577136. [PMID: 31855721 DOI: 10.1016/j.jneuroim.2019.577136] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 12/10/2019] [Accepted: 12/11/2019] [Indexed: 11/16/2022]
Abstract
Myasthenia gravis (MG) is an autoimmune disease affecting the neuromuscular junction. Approximately 9% of MG patients have autoantibodies targeting the muscle specific kinase (MuSK), and are challenging therapeutically, since they often present with more severe symptoms. A useful therapy is plasmapheresis, but it is highly non-specific. Antigen-specific immunoadsorption would only remove the pathogenic autoantibodies, minimizing the possible side effects and maximizing the benefit. We used rats with human MuSK-induced experimental autoimmune MG to perform antigen-specific immunoadsorptions, and found it very effective, resulting in a dramatic autoantibody titer decrease, while immunoadsorbed, but not mock-treated, animals showed an significant improvement of their clinical symptoms. Overall, the procedure was efficient, supporting its application for MG treatment.
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Affiliation(s)
| | | | | | - Socrates J Tzartos
- Hellenic Pasteur Institute, Athens, Greece; Tzartos NeuroDiagnostics, Athens, Greece.
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Rivner MH, Pasnoor M, Dimachkie MM, Barohn RJ, Mei L. Muscle-Specific Tyrosine Kinase and Myasthenia Gravis Owing to Other Antibodies. Neurol Clin 2019; 36:293-310. [PMID: 29655451 DOI: 10.1016/j.ncl.2018.01.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Around 20% of patients with myasthenia gravis are acetylcholine receptor antibody negative; muscle-specific tyrosine kinase antibodies (MuSK) were identified as the cause of myasthenia gravis in 30% to 40% of these cases. Anti MuSK myasthenia gravis is associated with specific clinical phenotypes. One is a bulbar form with fewer ocular symptoms. Others show an isolated head drop or symptoms indistinguishable from acetylcholine receptor-positive myasthenia gravis. These patients usually respond well to immunosuppressive therapy, but not as well to cholinesterase inhibitors. Other antibodies associated with myasthenia gravis, including low-density lipoprotein receptor-related protein 4, are discussed.
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Affiliation(s)
- Michael H Rivner
- EMG Lab, Augusta University, 1120 15th Street, BP-4390, Augusta, GA 30912, USA.
| | - Mamatha Pasnoor
- Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Mazen M Dimachkie
- Department of Neurology, University of Kansas Medical Center, 3599 Rainbow Boulevard, Mail Stop 2012, Kansas City, KS 66103, USA
| | - Richard J Barohn
- Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 4017, Kansas City, KS 66160, USA
| | - Lin Mei
- Department of Neuroscience and Regenerative Medicine, Augusta University, 1120 15th Street, CA-2014, Augusta, GA 30912, USA
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Abstract
Acquired Myasthenia Gravis (MG) is a neuromuscular disease caused by autoantibodies against components of the neuromuscular junction. It is a prototype organ-specific autoimmune disease with well-defined antigenic targets mainly the nicotinic acetylcholine receptor (AChR). Patients suffer from fluctuating, fatigable muscle weakness that worsens with activity and improves with rest. Various therapeutic strategies have been used over the years to alleviate MG symptoms. These strategies aim at improving the transmission of the nerve impulse to muscle or at lowering the immune system with steroids or immunosuppressant drugs. Nevertheless, MG remains a chronic disease and symptoms tend to persist in many patients, some being or becoming refractory over time. In this review, based on recent experimental data on MG or based on results from clinical trials for other autoimmune diseases, we explore new potential therapeutic approaches for MG patients, going from non-specific approaches with the use of stem cells with their anti-inflammatory and immunosuppressive properties to targeted therapies using monoclonal antibodies specific for cell-surface antigens or circulating molecules.
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Affiliation(s)
- Anthony Behin
- APHP, Centre de Référence des Maladies Neuromusculaires Nord/Est/Ile-de-France, Institut de Myologie, GH Pitié-Salpêtrière, Paris, France.,AIM, Institut de Myologie, Paris, France
| | - Rozen Le Panse
- INSERM U974, Paris, France.,UPMC Sorbonne Université, Paris, France.,AIM, Institut de Myologie, Paris, France
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Affiliation(s)
- Marc de Perrot
- Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Laura Donahoe
- Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
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Review on Toll-Like Receptor Activation in Myasthenia Gravis: Application to the Development of New Experimental Models. Clin Rev Allergy Immunol 2017; 52:133-147. [PMID: 27207173 DOI: 10.1007/s12016-016-8549-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Abnormal toll-like receptor (TLR) activation and uncontrolled resolution of inflammation are suspected to play a key role in the development of autoimmune diseases. Acquired myasthenia gravis (MG) is an invalidating neuromuscular disease leading to muscle weaknesses. MG is mainly mediated by anti-acetylcholine receptor (AChR) autoantibodies, and thymic hyperplasia characterized by ectopic germinal centers is a common feature in MG. An abnormal expression of certain TLRs is observed in the thymus of MG patients associated with the overexpression of interferon (IFN)-β, the orchestrator of thymic changes in MG. Experimental models have been developed for numerous autoimmune diseases. These models are induced by animal immunization with a purified antigen solubilized in complete Freund's adjuvant (CFA) containing heat-inactivated mycobacterium tuberculosis (MTB). Sensitization against the antigen is mainly due to the activation of TLR signaling pathways by the pathogen motifs displayed by MTB, and attempts have been made to substitute the use of CFA by TLR agonists. AChR emulsified in CFA is used to induce the classical experimental autoimmune MG model (EAMG). However, the TLR4 activator lipopolysaccharide (LPS) has proved to be efficient to replace MTB and induce a sensitization against purified AChR. Poly(I:C), the well-known TLR3 agonist, is also able by itself to induce MG symptoms in mice associated with early thymic changes as observed in human MG. In this review, we discuss the abnormal expression of TLRs in MG patients and we describe the use of TLR agonists to induce EAMG in comparison with other autoimmune experimental models.
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10
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Punga T, Le Panse R, Andersson M, Truffault F, Berrih-Aknin S, Punga AR. Circulating miRNAs in myasthenia gravis: miR-150-5p as a new potential biomarker. Ann Clin Transl Neurol 2013; 1:49-58. [PMID: 25356381 PMCID: PMC4207504 DOI: 10.1002/acn3.24] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 11/27/2013] [Accepted: 12/01/2013] [Indexed: 12/16/2022] Open
Abstract
Objective Myasthenia gravis (MG) is a chronic autoimmune disorder where autoantibodies target the nicotinic acetylcholine receptors (AChR+) in about 85% of cases, in which the thymus is considered to play a pathogenic role. As there are no reliable biomarkers to monitor disease status in MG, we analyzed circulating miRNAs in sera of MG patients to find disease-specific miRNAs. Methods Overall, 168 miRNAs were analyzed in serum samples from four AChR+ MG patients and four healthy controls using Exiqon Focus miRNA polymerase chain reaction (PCR) Panel I + II. Specific accumulation pattern of 13 miRNAs from the discovery set was subsequently investigated in the sera of 16 AChR+ MG patients and 16 healthy controls. All patients were without immunosuppressive treatment. Selected specific miRNAs were further analyzed in the serum of nine MG patients before and after thymectomy to assess the effect of thymus removal on the accumulation of the candidate miRNAs in patient sera. Results Three miRNAs were specifically dysregulated in AChR+ MG patient sera samples. Hsa-miR150-5p, which induces T-cell differentiation, as well as hsa-miR21-5p, a regulator of Th1 versus Th2 cell responses, were specifically elevated in MG sera. Additionally, hsa-miR27a-3p, involved in natural killer (NK) cell cytotoxicity, was decreased in MG. Hsa-miR150-5p levels had the highest association with MG and were significantly reduced after thymus removal in correlation with disease improvement. Interpretation We propose that the validated miRNAs: hsa-miR150-5p, hsa-miR21-5p, and hsa-miR27a-3p can serve as novel serum biomarkers in AChR+ MG. Hsa-miR-150-5p could be a helpful marker to monitor disease severity.
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Affiliation(s)
- Tanel Punga
- Department of Medical Biochemistry and Microbiology, Uppsala University BMC Box 582, Uppsala, Sweden
| | - Rozen Le Panse
- INSERM U974, CNRS UMR 7215, Institut de Myologie, UPMC Univ Paris 6 Paris, France
| | | | - Frédérique Truffault
- INSERM U974, CNRS UMR 7215, Institut de Myologie, UPMC Univ Paris 6 Paris, France
| | - Sonia Berrih-Aknin
- INSERM U974, CNRS UMR 7215, Institut de Myologie, UPMC Univ Paris 6 Paris, France
| | - Anna R Punga
- Department of Clinical Neurophysiology, Institute of Neuroscience, Uppsala University Uppsala, Sweden
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Huang GZ, Lo YL. Correlation between acetylcholine receptor antibody levels and thymic pathology in myasthenia gravis: a review. J Clin Neuromuscul Dis 2013; 14:209-217. [PMID: 23703018 DOI: 10.1097/cnd.0b013e31828a0090] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Myasthenia gravis is the most common chronic autoimmune neuromuscular disease. Anti-acetylcholine receptor (AChR) antibodies are found in at least 80% of patients with generalized myasthenia and have been implicated in disease pathogenesis. Thymic abnormalities are frequently found in seropositive patients, and the thymus is thought to be involved in generation of autoimmunity. This article reviews existing literature on the role of AChR antibodies in the pathogenesis of myasthenia gravis, and the correlation between AChR antibody titers and thymic pathology. Most studies found that highest titers are seen in thymic hyperplasia, followed by intermediate titers in thymoma, and lowest titers in atrophic or normal thymus. One publication found no difference between titers in thymoma and normal thymus.
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Affiliation(s)
- G Z Huang
- Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore
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Richman DP, Nishi K, Ferns MJ, Schnier J, Pytel P, Maselli RA, Agius MA. Animal models of antimuscle-specific kinase myasthenia. Ann N Y Acad Sci 2013; 1274:140-7. [PMID: 23252909 DOI: 10.1111/j.1749-6632.2012.06782.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Antimuscle-specific kinase (anti-MuSK) myasthenia (AMM) differs from antiacetylcholine receptor myasthenia gravis in exhibiting more focal muscle involvement (neck, shoulder, facial, and bulbar muscles) with wasting of the involved, primarily axial, muscles. AMM is not associated with thymic hyperplasia and responds poorly to anticholinesterase treatment. Animal models of AMM have been induced in rabbits, mice, and rats by immunization with purified xenogeneic MuSK ectodomain, and by passive transfer of large quantities of purified serum IgG from AMM patients into mice. The models have confirmed the pathogenic role of the MuSK antibodies in AMM and have demonstrated the involvement of both the presynaptic and postsynaptic components of the neuromuscular junction. The observations in this human disease and its animal models demonstrate the role of MuSK not only in the formation of this synapse but also in its maintenance.
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Affiliation(s)
- David P Richman
- Department of Neurology, Center for Neuroscience, University of California, Davis, 95616, USA.
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Calviño J, Adeva M, Sobrido MJ. Membranous nephropathy, leiomyoma and autoimmune myasthenia: more than a coincidence? Clin Kidney J 2012; 5:562-5. [PMID: 26069802 PMCID: PMC4400566 DOI: 10.1093/ckj/sfs144] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 09/12/2012] [Indexed: 11/14/2022] Open
Abstract
Membranous nephropathy (MN) has been associated with several infectious, immunological and malignant conditions, but had only rarely been reported with malignant and other immune disorders in the same patient. We describe the case of a 56-year-old male with MN who was also diagnosed with a gastrointestinal stromal tumour (GIST), myasthenia gravis (MG) and thymic hyperplasia. Thus, we report here for the first time the coincidence of these conditions in the same patient. There was a recurrence of nephrotic syndrome without impairment of renal function 5 years after removal of the GIST (3 years after thymectomy). The possible basis for the relationship between these diseases is discussed, and some common genetic and immune physiopathological pathways are hypothesized.
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Affiliation(s)
- Jesus Calviño
- Department of Nephrology , Hospital Lucus Augusti , Lugo , Spain
| | - Magdalena Adeva
- Department of Nephrology , Hospital Juan Cardona , Ferrol , Spain
| | - Maria-Jesus Sobrido
- Department of Neurogenetics , Fundación Publica Galega de Medicina Xenómica-SERGAS and Centre for Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III , Santiago Compostela , Spain
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14
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Kim JY, Park KD, Richman DP. Treatment of myasthenia gravis based on its immunopathogenesis. J Clin Neurol 2011; 7:173-83. [PMID: 22259613 PMCID: PMC3259491 DOI: 10.3988/jcn.2011.7.4.173] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 04/25/2011] [Accepted: 04/25/2011] [Indexed: 12/21/2022] Open
Abstract
The prognosis of myasthenia gravis (MG) has improved dramatically due to advances in critical-care medicine and symptomatic treatments. Its immunopathogenesis is fundamentally a T-cell-dependent autoimmune process resulting from loss of tolerance toward self-antigens in the thymus. Thymectomy is based on this immunological background. For MG patients who are inadequately controlled with sufficient symptomatic treatment or fail to achieve remission after thymectomy, remission is usually achieved through the addition of other immunotherapies. These immunotherapies can be classified into two groups: rapid induction and long-term maintenance. Rapid induction therapy includes intravenous immunoglobulin (IVIg) and plasma exchange (PE). These produce improvement within a few days after initiation, and so are useful for acute exacerbation including myasthenic crisis or in the perioperative period. High-dose prednisone has been more universally preferred for remission induction, but it acts more slowly than IVIg and PE, commonly only after a delay of several weeks. Slow tapering of steroids after a high-dose pulse offers a method of maintaining the state of remission. However, because of significant side effects, other immunosuppressants (ISs) are frequently added as "steroid-sparing agents". The currently available ISs exert their immunosuppressive effects by three mechanisms: 1) blocking the synthesis of DNA and RNA, 2) inhibiting T-cell activation and 3) depleting the B-cell population. In addition, newer drugs including antisense molecule, tumor necrosis factor alpha receptor blocker and complement inhibitors are currently under investigation to confirm their effectiveness. Until now, the treatment of MG has been based primarily on experience rather than gold-standard evidence from randomized controlled trials. It is hoped that well-organized studies and newer experimental trials will lead to improved treatments.
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Affiliation(s)
- Jee Young Kim
- Department of Neurology, Kwandong University College of Medicine, Myongji Hospital, Goyang, Korea
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Le Panse R, Bismuth J, Cizeron-Clairac G, Weiss JM, Cufi P, Dartevelle P, De Rosbo NK, Berrih-Aknin S. Thymic remodeling associated with hyperplasia in myasthenia gravis. Autoimmunity 2010; 43:401-12. [DOI: 10.3109/08916930903563491] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Abman SH, Matthay MA. Mesenchymal stem cells for the prevention of bronchopulmonary dysplasia: delivering the secretome. Am J Respir Crit Care Med 2009; 180:1039-41. [PMID: 19923401 DOI: 10.1164/rccm.200909-1330ed] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Prokakis C, Koletsis E, Salakou S, Apostolakis E, Baltayiannis N, Chatzimichalis A, Papapetropoulos T, Dougenis D. Modified Maximal Thymectomy for Myasthenia Gravis: Effect of Maximal Resection on Late Neurologic Outcome and Predictors of Disease Remission. Ann Thorac Surg 2009; 88:1638-45. [DOI: 10.1016/j.athoracsur.2009.07.036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Revised: 07/21/2009] [Accepted: 07/23/2009] [Indexed: 10/20/2022]
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