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Mantegazza R, Saccà F, Antonini G, Bonifati DM, Evoli A, Habetswallner F, Liguori R, Pegoraro E, Rodolico C, Schenone A, Sgarzi M, Pappagallo G. Therapeutic challenges and unmet needs in the management of myasthenia gravis: an Italian expert opinion. Neurol Sci 2024:10.1007/s10072-024-07577-7. [PMID: 38967883 DOI: 10.1007/s10072-024-07577-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 05/03/2024] [Indexed: 07/06/2024]
Abstract
Myasthenia gravis (MG) is a rare, autoimmune, neurological disorder. Most MG patients have autoantibodies against acetylcholine receptors (AChRs). Some have autoantibodies against muscle-specific tyrosine kinase (MuSK) or lipoprotein-receptor-related protein 4 (LRP4), and some are seronegative. Standard of care, which includes anti-cholinesterase drugs, thymectomy, corticosteroids (CS), and off-label use of non-steroidal immunosuppressive drugs (NSISTs), is bounded by potential side effects and limited efficacy in refractory generalized MG (gMG) patients. This highlights the need for new therapeutic approaches for MG. Eculizumab, a monoclonal antibody that inhibits the complement system, has been recently approved in Italy for refractory gMG. A panel of 11 experts met to discuss unmet therapeutic needs in the acute and chronic phases of the disease, as well as the standard of care for refractory patients. Survival was emphasized as an acute phase outcome. In the chronic phase, persistent remission and early recognition of exacerbations to prevent myasthenic crisis and respiratory failure were considered crucial. Refractory patients require treatments with fast onset of action, improved tolerability, and the ability to slow disease progression and increase life expectancy. The Panel agreed that eculizumab would presumably meet the therapeutic needs of many refractory gMG patients. The panel concluded that the unmet needs of current standard of care treatments for gMG are significant. Evaluating new therapeutic options accurately is essential to find the best balance between efficacy and tolerability for each patient. Collecting real-world data on novel molecules in routine clinical practice is necessary to address unmet needs.
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Affiliation(s)
- Renato Mantegazza
- Neuroimmunology and Neuromuscular Diseases Unit, IRCCS Foundation Carlo Besta Neurological Institute, Milan, Italy.
| | - Francesco Saccà
- NSRO Department, Federico II University of Naples, Naples, Italy
| | - Giovanni Antonini
- Department of Neurosciences, Mental Health and Sensory Organs (NESMOS), Sapienza University of Rome, Rome, Italy
| | - Domenico Marco Bonifati
- Neurology Unit, Cerebro-Cardiovascular Department, Ca' Foncello Hospital Treviso, Piazzale Ospedale 1, 31100, Treviso, Italy
| | - Amelia Evoli
- Neuroscience Department, Facolta Di Medicina E Chirurgia, Università Cattolica del Sacro Cuore, Rome, Italy
- Neurology Institute, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy
| | | | - Rocco Liguori
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
- IRCCS Istituto Delle Scienze Neurologiche Di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | | | - Carmelo Rodolico
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Angelo Schenone
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal and Infantile Sciences (DINOGMI), University and IRCCS San Martino Hospital, Genoa, Italy
| | - Manlio Sgarzi
- Department of Neurology, Papa Giovanni XXIII Hospital, Piazza OMS 1, 24127, Bergamo, Italy
| | - Giovanni Pappagallo
- School of Clinical Methodology, IRCCS "Sacred Heart - Don Calabria", Negrar Di Valpolicella, Italy
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Moffatt C, Pillutla P, Soltanzadeh P, Chhetri DK. Heterogeneous Presentations and Serologies in Myasthenia Gravis Patients Presenting with Dysphagia. Laryngoscope 2024. [PMID: 38949061 DOI: 10.1002/lary.31601] [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: 04/10/2024] [Revised: 05/27/2024] [Accepted: 06/07/2024] [Indexed: 07/02/2024]
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune disease that affects the neuromuscular junction. MG patients may present de novo with primary otolaryngology complaints, including swallowing dysfunction. This study describes a range of unique presentations and rare diagnostic serologies, which have not previously been fully described. METHODS A retrospective review was performed of all patients presenting with primary symptom of dysphagia and subsequently diagnosed with MG. Data collected included demographics, clinical presentation, swallow studies, serology, imaging, treatment, and response. RESULTS Five patients met the inclusion criteria. Four endorsed dysphagia as primary complaint and one endorsed dysphagia and dysphonia. All patients underwent in-office swallow evaluations that showed vallecular or pyriform sinus residue. Three patients completed modified barium swallow studies that showed pharyngeal weakness and epiglottic dysfunction in all, and upper esophageal sphincter dysfunction in two. One patient with additional symptom of dyspnea was admitted and found to be in myasthenic crisis. Upon serologic evaluation, three patients were positive for acetylcholine receptor (AChR) antibodies only, one for muscle-specific-kinase (MuSK) antibodies only, and one for low density lipoprotein receptor-related protein 4 (LRP4) antibodies only. All patients received neurology evaluation and were treated with steroids, pyridostigmine, plasma exchange, or rituximab. In three patients with over 1 year follow-up, symptoms were significantly improved or resolved. CONCLUSION MG is an important differential diagnosis in patients with unexplained pharyngeal dysphagia. While workup can include AChR antibody screening, in seronegative patients with persistent symptoms, additional testing for MuSK and LRP4 may lead to diagnosis and effective treatment. LEVEL OF EVIDENCE Level 4 Laryngoscope, 2024.
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Affiliation(s)
- Clare Moffatt
- Department of Head & Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Pranati Pillutla
- Department of Head & Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Payam Soltanzadeh
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
| | - Dinesh K Chhetri
- Department of Head & Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, U.S.A
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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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Ghimire A, Kunwar B, Aryal B, Gaire A, Bist A, Shah B, Mainali A, Ghimire B, Gajurel BP. Assessing the comparative efficacy of plasmapheresis and Intravenous immunoglobulin in myasthenia gravis treatment: A systematic review and meta-analysis. J Clin Neurosci 2024; 121:1-10. [PMID: 38306763 DOI: 10.1016/j.jocn.2024.01.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/28/2023] [Accepted: 01/29/2024] [Indexed: 02/04/2024]
Abstract
BACKGROUND Myasthenia gravis (MG) is an autoimmune neuromuscular disorder characterized by muscle weakness, posing significant challenges to patients' daily lives. Intravenous immunoglobulin (IVIG) and plasmapheresis are two prominent immunomodulatory therapies used in MG management, but the choice between them remains a clinical dilemma. This systematic review and meta-analysis aim to evaluate the comparative efficacy of IVIG versus plasmapheresis in MG management. METHODS We adhered to PRISMA guidelines and prospectively registered the review protocol in PROSPERO. Systematic search across electronic databases identified 14 studies meeting inclusion criteria. Data from these studies were extracted, and assessed risk of bias. Primary outcomes included clinical efficacy, while secondary outcomes encompassed hospitalization, ventilation, antibody titers, and treatment-related complications. Statistical analysis was conducted using R software. RESULTS The pooled results indicated that patients receiving plasmapheresis had higher odds of any improvement in MG symptoms compared to IVIG. However, change in severity scores did not significantly differ between the two treatments. Hospitalization durations were similar, but IVIG-treated patients tended to have shorter stays. Antibody titers, particularly anti-MUSK antibodies, favored plasmapheresis treatment. Complication rates were comparable between two groups. However, severe complications were more common in plasmapheresis. CONCLUSION This comprehensive analysis suggests that plasmapheresis may offer superior short-term symptom improvement in MG compared to IVIG, while IVIG may lead to shorter hospital stays and lower complication rates. The choice between these treatments should be tailored to individual patient needs and disease characteristics. Further research is needed to explore long-term outcomes and mortality rates in MG management.
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Affiliation(s)
- Anup Ghimire
- Maharajgunj Medical Campus, Tribhuvan University Institute of Medicine, Kathmandu, Nepal.
| | - Bijay Kunwar
- Maharajgunj Medical Campus, Tribhuvan University Institute of Medicine, Kathmandu, Nepal
| | - Binay Aryal
- Maharajgunj Medical Campus, Tribhuvan University Institute of Medicine, Kathmandu, Nepal
| | - Arjun Gaire
- Maharajgunj Medical Campus, Tribhuvan University Institute of Medicine, Kathmandu, Nepal
| | - Anil Bist
- Maharajgunj Medical Campus, Tribhuvan University Institute of Medicine, Kathmandu, Nepal
| | - Bilash Shah
- Maharajgunj Medical Campus, Tribhuvan University Institute of Medicine, Kathmandu, Nepal
| | - Atul Mainali
- Maharajgunj Medical Campus, Tribhuvan University Institute of Medicine, Kathmandu, Nepal
| | - Bikal Ghimire
- Kantipur Dental College Teaching Hospital &, Research Center, Basundhara, Kathmandu, Nepal
| | - Bikram Prasad Gajurel
- Department of Neurology, Maharajgunj Medical Campus, Tribhuvan University, Institute of Medicine, Kathmandu, Nepal
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Wang F, Cheng J, Niu X, Li L. Respiratory failure as first presentation of myasthenia gravis: a case report. J Int Med Res 2024; 52:3000605241234585. [PMID: 38443765 PMCID: PMC10916481 DOI: 10.1177/03000605241234585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 02/01/2024] [Indexed: 03/07/2024] Open
Abstract
Myasthenia gravis (MG) is often complicated by respiratory failure, an exacerbation known as myasthenic crisis. However, most patients with MG develop respiratory symptoms during the late course of the disease. Respiratory failure as an exclusive initial and primary complaint in patients with MG is rare and seldom reported. We herein describe a woman in her late 50s who presented with respiratory failure and was diagnosed with obesity hypoventilation syndrome at a local hospital. Her condition gradually worsened during the next 4 months and became accompanied by dysphagia. After 1 year of medical investigation, she was diagnosed in our hospital. A high level of anti-muscle-specific receptor tyrosine kinase antibody was found in her serum, and stimulation and electromyography results suggested MG. The patient's symptoms were improved by intravenous immunoglobulin and hormone therapy. This case reminds physicians to consider MG when encountering a patient who initially presents with respiratory failure.
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Affiliation(s)
- Fangming Wang
- Hebei Medical University Graduate School, Shijiazhuang, China
| | - Jinming Cheng
- Department of Neurology, Hebei General Hospital, Shijiazhuang, China
| | - Xiaoli Niu
- Department of Neurology, Hebei General Hospital, Shijiazhuang, China
| | - Litao Li
- Department of Neurology, Hebei General Hospital, Shijiazhuang, China
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Vakrakou AG, Karachaliou E, Chroni E, Zouvelou V, Tzanetakos D, Salakou S, Papadopoulou M, Tzartos S, Voumvourakis K, Kilidireas C, Giannopoulos S, Tsivgoulis G, Tzartos J. Immunotherapies in MuSK-positive Myasthenia Gravis; an IgG4 antibody-mediated disease. Front Immunol 2023; 14:1212757. [PMID: 37564637 PMCID: PMC10410455 DOI: 10.3389/fimmu.2023.1212757] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 07/05/2023] [Indexed: 08/12/2023] Open
Abstract
Muscle-specific kinase (MuSK) Myasthenia Gravis (MG) represents a prototypical antibody-mediated disease characterized by predominantly focal muscle weakness (neck, facial, and bulbar muscles) and fatigability. The pathogenic antibodies mostly belong to the immunoglobulin subclass (Ig)G4, a feature which attributes them their specific properties and pathogenic profile. On the other hand, acetylcholine receptor (AChR) MG, the most prevalent form of MG, is characterized by immunoglobulin (Ig)G1 and IgG3 antibodies to the AChR. IgG4 class autoantibodies are impotent to fix complement and only weakly bind Fc-receptors expressed on immune cells and exert their pathogenicity via interfering with the interaction between their targets and binding partners (e.g. between MuSK and LRP4). Cardinal differences between AChR and MuSK-MG are the thymus involvement (not prominent in MuSK-MG), the distinct HLA alleles, and core immunopathological patterns of pathology in neuromuscular junction, structure, and function. In MuSK-MG, classical treatment options are usually less effective (e.g. IVIG) with the need for prolonged and high doses of steroids difficult to be tapered to control symptoms. Exceptional clinical response to plasmapheresis and rituximab has been particularly observed in these patients. Reduction of antibody titers follows the clinical efficacy of anti-CD20 therapies, a feature implying the role of short-lived plasma cells (SLPB) in autoantibody production. Novel therapeutic monoclonal against B cells at different stages of their maturation (like plasmablasts), or against molecules involved in B cell activation, represent promising therapeutic targets. A revolution in autoantibody-mediated diseases is pharmacological interference with the neonatal Fc receptor, leading to a rapid reduction of circulating IgGs (including autoantibodies), an approach already suitable for AChR-MG and promising for MuSK-MG. New precision medicine approaches involve Chimeric autoantibody receptor T (CAAR-T) cells that are engineered to target antigen-specific B cells in MuSK-MG and represent a milestone in the development of targeted immunotherapies. This review aims to provide a detailed update on the pathomechanisms involved in MuSK-MG (cellular and humoral aberrations), fostering the understanding of the latest indications regarding the efficacy of different treatment strategies.
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Affiliation(s)
- Aigli G. Vakrakou
- First Department of Neurology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Eleni Karachaliou
- Second Department of Neurology, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Elisabeth Chroni
- Department of Neurology, School of Medicine, University of Patras, Patras, Greece
| | - Vasiliki Zouvelou
- First Department of Neurology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Dimitrios Tzanetakos
- Second Department of Neurology, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Stavroula Salakou
- Second Department of Neurology, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Marianna Papadopoulou
- Second Department of Neurology, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
- Department of Physiotherapy, University of West Attica, Athens, Greece
| | - Socrates Tzartos
- Tzartos NeuroDiagnostics, Athens, Greece
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
- Department of Pharmacy, University of Patras, Patras, Greece
| | - Konstantinos Voumvourakis
- Second Department of Neurology, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Constantinos Kilidireas
- First Department of Neurology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- Department of Neurology, Henry Dunant Hospital Center, Athens, Greece
| | - Sotirios Giannopoulos
- Second Department of Neurology, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Georgios Tsivgoulis
- Second Department of Neurology, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
- Department of Neurology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - John Tzartos
- Second Department of Neurology, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
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Yang J, Wu J, Han T, Lu H, Li F, Li L, Su S, Jiang P, Hou Z. Global research hotspots and frontiers of myasthenia gravis from 2002 to 2021: A bibliometric study. Medicine (Baltimore) 2023; 102:e34002. [PMID: 37327308 PMCID: PMC10270528 DOI: 10.1097/md.0000000000034002] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 05/24/2023] [Indexed: 06/18/2023] Open
Abstract
The objective of this study is to utilize bibliometric and visual analysis techniques to identify hotspots and frontiers of research in myasthenia gravis (MG) and provide valuable references for future research. The Web of Science Core Collection (WoSCC) database was used to retrieve literature data related to MG research, which was then analyzed using VOSviewer 1.6.18, CiteSpace 6.1.R3, and the Online Platform for Bibliometric Analysis. The analysis revealed 6734 publications distributed across 1612 journals and contributed by as many as 24,024 authors affiliated with 4708 institutions across 107 countries/regions. The number of annual publications and citations for MG research has steadily increased over the past 2 decades, with the last 2 years alone witnessing a remarkable increase in annual publications and citations to over 600 and 17,000, respectively. In terms of productivity, the United States emerged as the top producing country, while the University of Oxford ranked first in terms of research institutions. Vincent A was identified as the top contributor in terms of publications and citations. Muscle & Nerve and Neurology ranked first in publications and citations respectively, with clinical neurology and neurosciences among the main subject categories explored. The study also identified pathogenesis, eculizumab, thymic epithelial cells, immune checkpoint inhibitors, thymectomy, MuSK antibodies, risk, diagnosis, and management as the current hot research topics in MG, while burst keywords like quality of life, immune-related adverse events (irAEs), rituximab, safety, nivolumab, cancer, and classification indicated the frontiers of MG research. This study effectively identifies the hotspots and frontiers of MG research, and offers valuable references for researchers interested in this area.
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Affiliation(s)
- Jiali Yang
- Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, China
| | - Jiaojiao Wu
- Xiangyu Pharmaceutical Co., Ltd., Linyi, China
| | - Tingliang Han
- Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, China
| | - Hua Lu
- Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, China
| | - Fangcun Li
- Guilin Municipal Hospital of Traditional Chinese Medicine, Guilin, China
| | - Leilei Li
- Guangxi University of Chinese Medicine, Nanning, China
| | - Shaoting Su
- Guangxi University of Chinese Medicine, Nanning, China
| | - Ping Jiang
- Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhaomeng Hou
- Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, China
- Guangxi University of Chinese Medicine, Nanning, China
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García Estévez DA, Pardo Fernández J. Myasthenia gravis. Update on diagnosis and therapy. Med Clin (Barc) 2023:S0025-7753(23)00218-X. [PMID: 37248131 DOI: 10.1016/j.medcli.2023.04.006] [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: 02/27/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/31/2023]
Abstract
Myasthenia gravis is an autoimmune disease caused by the presence of specific antibodies targeting different postsynaptic components of the neuromuscular junction, and is clinically characterized by the presence of fatigueable muscle weakness. In the etiopathogenesis plays a central role the thymus and the most frequently detected pathogenic autoantibodies are targeted to the acetylcholine receptor. The increase in the knowledge of the immunological components of the neuromuscular junction in the last two decades has been fundamental to identify new pathogenic antibodies, reduce the percentage of patients with seronegative myasthenia, and propose a classification of patients into subgroups with clinical-therapeutic interest. In addition, in recent years, new drugs have been developed for the treatment of patients with myasthenia gravis that are refractory to conventional immunosuppressive treatment.
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Affiliation(s)
- Daniel Apolinar García Estévez
- Servicio de Neurología, Complexo Hospitalario Universitario de Ourense, Ourense, España; Grupo de investigación Neurociencias Clínicas, Instituto de Investigaciones Sanitarias Galicia-Sur, SERGAS-UVIGO, Vigo, Pontevedra, España.
| | - Julio Pardo Fernández
- Unidad de Enfermedades Neuromusculares, Servicio de Neurología, Complexo Hospitalario Universitario de Santiago de Compostela. Facultad de Medicina, Universidad de Santiago de Compostela, Santiago de Compostela, A Coruña, España
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Hehir MK, Li Y. Diagnosis and Management of Myasthenia Gravis. Continuum (Minneap Minn) 2022; 28:1615-1642. [PMID: 36537972 DOI: 10.1212/con.0000000000001161] [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: 12/24/2022]
Abstract
PURPOSE OF REVIEW This article reviews updated diagnostic procedures and currently available treatment modalities for myasthenia gravis (MG). RECENT FINDINGS Patients with MG can be classified based on antibody status and their clinical presentation; treatment responses may differ based on disease subtypes. Improved diagnostic methods and recognition of new antigenic targets such as lipoprotein-related protein 4 have led to improved diagnostic efficiencies. Corticosteroids remain the first-line immunotherapy, but there is a trend toward minimizing their use at high doses and for long durations. Oral immunosuppressants such as mycophenolate mofetil, azathioprine, and tacrolimus remain useful. An international, multicenter randomized trial comparing thymectomy plus prednisone with prednisone alone demonstrated that thymectomy improves clinical outcomes in selected patients with nonthymomatous MG. Eculizumab, efgartigimod, and ravulizumab have recently been approved by the US Food and Drug Administration (FDA) for adult patients with generalized MG who are acetylcholine receptor-antibody positive. These drugs take advantage of novel mechanisms of action and expand treatment options for patients with MG. Data on rituximab suggest that it can be a good option, especially for patients with MG who are positive for antibodies against muscle-specific tyrosine kinase (MuSK). The number of clinical trials and drugs in development for MG is steadily increasing. SUMMARY The diagnosis of MG can generally be made from the patient's history, a neurologic examination, and laboratory and electrodiagnostic testing. Carefully selected treatment improves outcomes in MG. Additional treatment options for MG will likely be available in the near future.
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Alcantara M, Barnett C, Katzberg H, Bril V. An update on the use of immunoglobulins as treatment for myasthenia gravis. Expert Rev Clin Immunol 2022; 18:703-715. [PMID: 35639497 DOI: 10.1080/1744666x.2022.2084074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Myasthenia gravis (MG) is an antibody mediated disease where pathogenic antibodies interact with the acetylcholine receptor or other proteins at the post-synaptic neuromuscular junction. There is growing evidence that immunoglobulin infusions are beneficial for clinical exacerbations and chronic refractory disease and may be an option for patients unresponsive to conventional immunosuppressive therapies. AREAS COVERED We performed an extensive literature review, looking for evidence on the use of immunoglobulins for the treatment of MG, by conducting a search in MEDLINE (1946 to present), EMBASE (1947 to present) and Clinicaltrials.gov. We have included studies on the use of intravenous immunoglobulins (IVIG) and subcutaneous immunoglobulins (SCIG) for acute deterioration and chronic disease. EXPERT OPINION The use of IVIG in MG provides an option for rapid improvement in critical deterioration, being preferred over more invasive and less available therapies such as plasmapheresis. For refractory MG, the addition of IVIG can improve a patient's status and reduce the dosage of immunosuppressive medications. The alternative of SCIG is also effective and has advantages of infusion time flexibility, fewer side-effects, and patient independence. The safety and efficacy of both interventions, patient preferences and quality of life may direct therapeutic choices in the future.
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Affiliation(s)
- Monica Alcantara
- Ellen & Martin Prosserman Centre for Neuromuscular Diseases, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Carolina Barnett
- Ellen & Martin Prosserman Centre for Neuromuscular Diseases, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada.,Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto
| | - Hans Katzberg
- Ellen & Martin Prosserman Centre for Neuromuscular Diseases, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Vera Bril
- Ellen & Martin Prosserman Centre for Neuromuscular Diseases, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
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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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12
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Gungor Tuncer O, Deymeer F. Clinical course and outcome of an outpatient clinic population with myasthenia gravis and COVID-19. Muscle Nerve 2022; 65:447-452. [PMID: 35040147 PMCID: PMC9015549 DOI: 10.1002/mus.27497] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/01/2022] [Accepted: 01/08/2022] [Indexed: 11/21/2022]
Abstract
Introduction/Aims Coronavirus disease‐2019 (COVID‐19) may have a more severe course in patients with myasthenia gravis (MG). We aimed to assess severity of the infection and factors contributing to its severity in a group of MG patients, most of whom were not hospitalized. Methods One hundred forty outpatients with MG followed between March 2020 and April 2021 were included in our study. Patients were asked to respond to a brief questionnaire in person, by telemedicine, or through electronic messages. Results Nineteen patients tested positive for COVID‐19 by polymerase chain reaction. Two were asymptomatic. Of the 17 symptomatic patients, 11 had mild symptoms. They either had no treatment or received antivirals, antibiotics, and anticoagulants. Their myasthenia was well‐controlled before infection and was unaffected by COVID‐19. Three patients with moderate COVID‐19 required hospitalization, but not intensive care, and had full recovery. Three other patients, the oldest in the cohort, had severe disease: One patient with a postsurgery myasthenic exacerbation before the infection needed intensive care without intubation, but recovered completely; two morbidly obese patients with comorbidities required intubation and died. Corticosteroids were increased in four of the six moderate/severely affected patients. Immunosuppressive (IS) agents were generally continued. Hydroxychloroquine (HCQ) for COVID‐19 was used in one patient. Discussion Most patients had mild COVID‐19 and all but two patients recovered. The design of the study made it possible to capture mild cases. Having well‐controlled MG before infection and absence of comorbidities likely affected the course of the infection favorably. IS did not influence the progression.
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Affiliation(s)
| | - Feza Deymeer
- Department of Neurology, Memorial Sisli Hospital, Istanbul, Turkey
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13
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Muscle-Specific Tyrosine Kinase-Associated Myasthenia Gravis: A Neuromuscular Surprise. Case Rep Neurol Med 2022; 2021:1326442. [PMID: 34992891 PMCID: PMC8727168 DOI: 10.1155/2021/1326442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 12/22/2021] [Indexed: 11/18/2022] Open
Abstract
Myasthenia gravis is a neuromuscular autoimmune disease that results in skeletal muscle weakness that worsens after periods of activity and improves after rest. Myasthenia gravis means "grave (serious), muscle weakness." Although not completely curable, it can be managed well with a relatively high quality of life and expectancy. In myasthenia gravis, antibodies against the acetylcholine receptors at the neuromuscular junction interfere with regular muscular contraction. Although most commonly caused by antibodies to the acetylcholine receptor, antibodies against MuSK (muscle-specific kinase) protein can also weaken transmission at the neuromuscular junction. Muscle-specific tyrosine kinase myasthenia gravis (MuSK-Ab MG) is a rare subtype of myasthenia gravis with distinct pathogenesis and unique clinical features. Diagnosis can be challenging due to its atypical presentation as compared to seropositive myasthenia gravis. It responds inconsistently to steroids, but plasma exchange and immunosuppressive therapies have shown promising results. We report a case of a 49-year-old female who presented with acute hypoxic respiratory failure. Our patient experienced progressive, undiagnosed MuSK-Ab MG for years without a diagnosis.
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14
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Treatment and Management of Disorders of the Neuromuscular Junction. Neuromuscul Disord 2022. [DOI: 10.1016/b978-0-323-71317-7.00019-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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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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16
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Ipe TS, Davis AR, Raval JS. Therapeutic Plasma Exchange in Myasthenia Gravis: A Systematic Literature Review and Meta-Analysis of Comparative Evidence. Front Neurol 2021; 12:662856. [PMID: 34531809 PMCID: PMC8439193 DOI: 10.3389/fneur.2021.662856] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 07/12/2021] [Indexed: 01/04/2023] Open
Abstract
Background: Patients with Myasthenia Gravis (MG) can be treated acutely with therapeutic plasma exchange (TPE) or intravenous immune globulin (IVIG). To date, there is no definitive understanding of which of the two treatments is more effective and safer. The purpose of this study was to systematically review the literature on the comparative efficacy and safety of TPE to other available treatments for MG. Methods: A systematic literature search for studies published between 1997 and 2017 was performed per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using two database sources, MEDLINE (through the PubMed database) and Cochrane Library. Results: The search strategy resulted in 535 articles whose abstracts were reviewed. Among these, 165 full texts articles were reviewed for eligibility and 101 articles were excluded. Of the 165 articles, 64 articles were included for a systematic literature and 11 articles for a meta-analysis. Conclusions: This systematic literature review and meta-analysis of treatment options showed that there was a higher response rate with TPE than IVIG in acute MG patients and patients undergoing thymectomy. There was no difference in mortality between the two treatment options. Our findings highlight the need for additional randomized clinical trials in these patients with MG.
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Affiliation(s)
- Tina S. Ipe
- Department of Pathology and Laboratory Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Adeola R. Davis
- Terumo Blood and Cell Technologies, Lakewood, CO, United States
| | - Jay S. Raval
- Department of Pathology, University of New Mexico, Albuquerque, NM, United States
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17
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Myasthenia Gravis: Epidemiology, Pathophysiology and Clinical Manifestations. J Clin Med 2021; 10:jcm10112235. [PMID: 34064035 PMCID: PMC8196750 DOI: 10.3390/jcm10112235] [Citation(s) in RCA: 124] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/17/2021] [Accepted: 05/17/2021] [Indexed: 12/12/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune neurological disorder characterized by defective transmission at the neuromuscular junction. The incidence of the disease is 4.1 to 30 cases per million person-years, and the prevalence rate ranges from 150 to 200 cases per million. MG is considered a classic example of antibody-mediated autoimmune disease. Most patients with MG have autoantibodies against the acetylcholine receptors (AChRs). Less commonly identified autoantibodies include those targeted to muscle-specific kinase (MuSK), low-density lipoprotein receptor-related protein 4 (Lrp4), and agrin. These autoantibodies disrupt cholinergic transmission between nerve terminals and muscle fibers by causing downregulation, destruction, functional blocking of AChRs, or disrupting the clustering of AChRs in the postsynaptic membrane. The core clinical manifestation of MG is fatigable muscle weakness, which may affect ocular, bulbar, respiratory and limb muscles. Clinical manifestations vary according to the type of autoantibody, and whether a thymoma is present.
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18
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Bennani HN, Lagrange E, Noble J, Malvezzi P, Motte L, Chevallier E, Rostaing L, Jouve T. Treatment of refractory myasthenia gravis by double-filtration plasmapheresis and rituximab: A case series of nine patients and literature review. J Clin Apher 2020; 36:348-363. [PMID: 33349954 DOI: 10.1002/jca.21868] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/03/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune disease mediated by circulating autoantibodies (anti-AchR, anti-MuSK, etc.). More than 20% of myasthenic patients are refractory to conventional treatments (plasma exchange, IVIg, steroids, azathioprine, mycophenolate mofetil). Rituximab (B-lymphocyte-depleting anti-CD20) and apheresis (double-filtration plasmapheresis [DFPP] and immunoadsorption [IA]) are interesting therapeutic alternatives. METHODS This monocentric pilot study included nine refractory myasthenic patients (March 2018 to May 2020) treated by DFPP and/or IA associated with rituximab (375 mg/m2 ). Clinical responses were assessed using the Myasthenia Gravis Foundation of America (MGFA) score. RESULTS Average age of patients was 53 ± 17 years. Gender ratio (M/F) was 3:6. The combination of apheresis and rituximab reduced median MGFA score from IV to II after 12 months of follow-up. Clinical improvement assessed by MGFA score was sustained in the long-term for all patients, during an average follow-up of 14 ± 9 months, allowing them to be self-sufficient and out sick-leave. The median number of apheresis sessions was 7 (5-30). The dose of prednisolone was reduced in two patients from 40 mg/d and 30 mg/d to 7.5 mg/d and 10 mg/d, respectively. It was stopped in a patient who was taking 30 mg/d. No infectious, bleeding, or thrombosis complications were noted. CONCLUSION The combination of rituximab and DFPP was effective to treat refractory MG.
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Affiliation(s)
- Hamza N Bennani
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Emmeline Lagrange
- Exploration Fonctionnelle du Système Nerveux instead of Service de Neurologie, CHU Grenoble, La Tronche, France
| | - Johan Noble
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Paolo Malvezzi
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Lionel Motte
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Eloi Chevallier
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Lionel Rostaing
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France.,Université Grenoble-Alpes, La Tronche, France
| | - Thomas Jouve
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France.,Université Grenoble-Alpes, La Tronche, France
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19
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Matsumoto Y, Shima K, Yamaguchi K, Shimizu A. [A case of anti-MuSK positive MG with recurrent right-sided heart failure as the initial manifestation]. Rinsho Shinkeigaku 2020; 60:791-794. [PMID: 33115997 DOI: 10.5692/clinicalneurol.cn-001475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We report a case of anti-MuSK antibody (Ab)-positive myasthenia gravis (MG) in a patient who developed recurrent right-sided congestive heart failure. The patient presented with right-sided congestive heart failure of unknown etiology, necessitating hospitalization on three occasions over a 6-month period. During the third episode of hospitalization, she developed disturbance of consciousness, and heart failure was attributed to carbon dioxide narcosis. We performed various investigations including an anti-MuSK Ab assay, which showed positive results, and she was diagnosed with MG based solely on anti-MuSK Ab positivity. Selective plasma exchange did not produce a satisfactory therapeutic effect, and she received additional intravenous immunoglobulin, plasmapheresis, and oral immunosuppressive therapy after which she was successfully weaned off the ventilator. This case report highlights the following points: (a) Recurrent right-sided congestive heart failure may be the first manifestation of anti-MuSK Ab-positive MG and, (b) detection of the anti-MuSK Ab alone is a convincing rationale to diagnose patients with MG.
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Affiliation(s)
| | - Keisuke Shima
- Department of Neurology, Ishikawa Prefectural Central Hospital.,Department of Neurology, Toyama Prefectural Central Hospital
| | | | - Ai Shimizu
- Department of Neurology, Kanazawa Medical Center
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20
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Cao M, Koneczny I, Vincent A. Myasthenia Gravis With Antibodies Against Muscle Specific Kinase: An Update on Clinical Features, Pathophysiology and Treatment. Front Mol Neurosci 2020; 13:159. [PMID: 32982689 PMCID: PMC7492727 DOI: 10.3389/fnmol.2020.00159] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/03/2020] [Indexed: 12/24/2022] Open
Abstract
Muscle Specific Kinase myasthenia gravis (MuSK-MG) is an autoimmune disease that impairs neuromuscular transmission leading to generalized muscle weakness. Compared to the more common myasthenia gravis with antibodies against the acetylcholine receptor (AChR), MuSK-MG affects mainly the bulbar and respiratory muscles, with more frequent and severe myasthenic crises. Treatments are usually less effective with the need for prolonged, high doses of steroids and other immunosuppressants to control symptoms. Under physiological condition, MuSK regulates a phosphorylation cascade which is fundamental for the development and maintenance of postsynaptic AChR clusters at the neuromuscular junction (NMJ). Agrin, secreted by the motor nerve terminal into the synaptic cleft, binds to low density lipoprotein receptor-related protein 4 (LRP4) which activates MuSK. In MuSK-MG, monovalent MuSK-IgG4 autoantibodies block MuSK-LRP4 interaction preventing MuSK activation and leading to the dispersal of AChR clusters. Lower levels of divalent MuSK IgG1, 2, and 3 antibody subclasses are also present but their contribution to the pathogenesis of the disease remains controversial. This review aims to provide a detailed update on the epidemiological and clinical features of MuSK-MG, focusing on the pathophysiological mechanisms and the latest indications regarding the efficacy and safety of different treatment options.
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Affiliation(s)
- Michelangelo Cao
- Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Inga Koneczny
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
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21
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Rodolico C, Bonanno C, Toscano A, Vita G. MuSK-Associated Myasthenia Gravis: Clinical Features and Management. Front Neurol 2020; 11:660. [PMID: 32793097 PMCID: PMC7390870 DOI: 10.3389/fneur.2020.00660] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/02/2020] [Indexed: 01/04/2023] Open
Abstract
Muscle-specific tyrosine kinase (MuSK) myasthenia gravis (MG) is a rare, frequently more severe, subtype of MG with different pathogenesis, and peculiar clinical features. The prevalence varies among countries and ethnic groups, affecting 5–8% of all MG patients. MuSK-MG usually has an acute onset affecting mainly the facial-bulbar muscles. The symptoms usually progress rapidly, within a few weeks. Early respiratory crises are frequent. The disease may lead to generalized muscle weakness up to muscle atrophy. The main bulbar involvement, the absence of significant thymus alterations, and the association with HLA class II DR14, DR16, and DQ5 alleles have been confirmed. Atypical onset, such as ocular involvement, lack of symptom fluctuations, acetylcholinesterase inhibitors failure, and negative results of electrophysiologic testing, if not specifically performed in the mainly involved muscle groups, makes MuSK-MG diagnosis challenging. In most cases, steroids are effective. Conventional immunosuppressants are not commonly able to replace steroids in maintaining a satisfactory long-term control of symptoms. However, the majority of MuSK-MG patients are refractory to treatment. In these cases, the use of rituximab showed promising results, resulting in sustained symptom control.
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Affiliation(s)
- Carmelo Rodolico
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Carmen Bonanno
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Antonio Toscano
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Giuseppe Vita
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
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22
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AChR myasthenia gravis switching to MuSK or double antibody positive myasthenia gravis in two children and literature review. Neuromuscul Disord 2020; 30:534-538. [DOI: 10.1016/j.nmd.2020.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 02/14/2020] [Accepted: 03/23/2020] [Indexed: 11/21/2022]
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23
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Nguyen T, Phan CL, Supsupin E, Sheikh K. Therapeutic and Diagnostic Challenges in Myasthenia Gravis. Neurol Clin 2020; 38:577-590. [PMID: 32703470 DOI: 10.1016/j.ncl.2020.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
"Myasthenia gravis (MG) is the most common autoimmune neuromuscular disorder. This article highlights several cases that the practicing neurologist may encounter in the treatment of MG. Diagnostic uncertainty continues to be an issue in patients who are seronegative to the 2 most common antibodies, acetylcholine receptor and muscle-specific tyrosine kinase (MuSK). Specific populations of patients with MG including MuSK MG, thymomatous MG, refractory MG, and pregnant women also require special consideration. This article reviews specific cases and an update on current management."
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Affiliation(s)
- Thy Nguyen
- Department of Neurology, McGovern Medical School, University of Texas Houston Health Science Center, 6431 Fannin Street, MSE R 462, Houston, TX 77030, USA.
| | - Cecile L Phan
- 7-125 Clinical Sciences Building, 2J2.00 WC Mackenzie Health Sciences Centre, 8440 112 St. NW, Edmonton, Alberta, T6G 2R7 Canada
| | - Emilio Supsupin
- Department of Diagnostic and Interventional Imaging, 6431 Fannin St. 2.103 MSMB, Houston, Texas 77030, USA
| | - Kazim Sheikh
- Department of Neurology, McGovern Medical School, University of Texas Houston Health Science Center, 6431 Fannin street, MSE R454 Houston, TX 77030, USA
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Takamori M. Myasthenia Gravis: From the Viewpoint of Pathogenicity Focusing on Acetylcholine Receptor Clustering, Trans-Synaptic Homeostasis and Synaptic Stability. Front Mol Neurosci 2020; 13:86. [PMID: 32547365 PMCID: PMC7272578 DOI: 10.3389/fnmol.2020.00086] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/28/2020] [Indexed: 12/18/2022] Open
Abstract
Myasthenia gravis (MG) is a disease of the postsynaptic neuromuscular junction (NMJ) where nicotinic acetylcholine (ACh) receptors (AChRs) are targeted by autoantibodies. Search for other pathogenic antigens has detected the antibodies against muscle-specific tyrosine kinase (MuSK) and low-density lipoprotein-related protein 4 (Lrp4), both causing pre- and post-synaptic impairments. Agrin is also suspected as a fourth pathogen. In a complex NMJ organization centering on MuSK: (1) the Wnt non-canonical pathway through the Wnt-Lrp4-MuSK cysteine-rich domain (CRD)-Dishevelled (Dvl, scaffold protein) signaling acts to form AChR prepatterning with axonal guidance; (2) the neural agrin-Lrp4-MuSK (Ig1/2 domains) signaling acts to form rapsyn-anchored AChR clusters at the innervated stage of muscle; (3) adaptor protein Dok-7 acts on MuSK activation for AChR clustering from “inside” and also on cytoskeleton to stabilize AChR clusters by the downstream effector Sorbs1/2; (4) the trans-synaptic retrograde signaling contributes to the presynaptic organization via: (i) Wnt-MuSK CRD-Dvl-β catenin-Slit 2 pathway; (ii) Lrp4; and (iii) laminins. The presynaptic Ca2+ homeostasis conditioning ACh release is modified by autoreceptors such as M1-type muscarinic AChR and A2A adenosine receptors. The post-synaptic structure is stabilized by: (i) laminin-network including the muscle-derived agrin; (ii) the extracellular matrix proteins (including collagen Q/perlecan and biglycan which link to MuSK Ig1 domain and CRD); and (iii) the dystrophin-associated glycoprotein complex. The study on MuSK ectodomains (Ig1/2 domains and CRD) recognized by antibodies suggested that the MuSK antibodies were pathologically heterogeneous due to their binding to multiple functional domains. Focussing one of the matrix proteins, biglycan which functions in the manner similar to collagen Q, our antibody assay showed the negative result in MG patients. However, the synaptic stability may be impaired by antibodies against MuSK ectodomains because of the linkage of biglycan with MuSK Ig1 domain and CRD. The pathogenic diversity of MG is discussed based on NMJ signaling molecules.
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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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26
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Abstract
PURPOSE OF REVIEW "Double vision" is a commonly encountered concern in neurologic practice; the experience of diplopia is always sudden and is frequently a cause of great apprehension and potential disability for patients. Moreover, while some causes of diplopia are benign, others require immediate recognition, a focused diagnostic evaluation, and appropriate treatment to prevent vision- and life-threatening outcomes. A logical, easy-to-follow approach to the clinical evaluation of patients with diplopia is helpful in ensuring accurate localization, a comprehensive differential diagnosis, and optimal patient care. This article provides a foundation for formulating an approach to the patient with diplopia and includes practical examples of developing the differential diagnosis, effectively using confirmatory examination techniques, determining an appropriate diagnostic strategy, and (where applicable) providing effective treatment. RECENT FINDINGS Recent population-based analyses have determined that diplopia is a common presentation in both ambulatory and emergency department settings, with 850,000 such visits occurring annually. For patients presenting to an outpatient facility, diagnoses are rarely serious. However, potentially life-threatening causes (predominantly stroke or transient ischemic attack) can be encountered. In patients presenting with diplopia related to isolated cranial nerve palsy, immediate neuroimaging can often be avoided if an appropriate history and examination are used to exclude worrisome etiologies. SUMMARY Binocular diplopia is most often due to a neurologic cause. The onset of true "double vision" is debilitating for most patients and commonly prompts immediate access to health care services as a consequence of functional impairment and concern for worrisome underlying causes. Although patients may seek initial evaluation through the emergency department or from their primary care/ophthalmic provider, elimination of an ocular cause will not infrequently result in the patient being referred for neurologic consultation. A logical, localization-driven, and evidence-based approach is the most effective way to arrive at the correct diagnosis and provide the best outcome for the patient.
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27
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Maintenance immunosuppression in myasthenia gravis, an update. J Neurol Sci 2019; 410:116648. [PMID: 31901719 DOI: 10.1016/j.jns.2019.116648] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/25/2019] [Accepted: 12/24/2019] [Indexed: 01/08/2023]
Abstract
Therapies for myasthenia gravis (MG) include symptomatic and immunosuppressive/immunomodulatory treatment. Options for immunosuppression include corticosteroids, azathioprine, mycophenolate mofetil, cyclosporine, tacrolimus, methotrexate, rituximab, cyclophosphamide, eculizumab, intravenous immunoglobulin, subcutaneous immunoglobulin, plasmapheresis, and thymectomy. The practical aspects of long-term immunosuppressive therapy in MG are critically reviewed in this article. Application of one or more of these specific therapies is guided based on known efficacy, adverse effect profile, particular disease subtype and severity, and patient co-morbidities.
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Dubey D, Britton J, McKeon A, Gadoth A, Zekeridou A, Lopez Chiriboga SA, Devine M, Cerhan JH, Dunlay K, Sagen J, Ramberger M, Waters P, Irani SR, Pittock SJ. Randomized Placebo-Controlled Trial of Intravenous Immunoglobulin in Autoimmune LGI1/CASPR2 Epilepsy. Ann Neurol 2019; 87:313-323. [PMID: 31782181 PMCID: PMC7003900 DOI: 10.1002/ana.25655] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/25/2019] [Accepted: 11/25/2019] [Indexed: 12/23/2022]
Abstract
Objective Drug‐resistant seizures are common in patients with leucine‐rich, glioma‐inactivated 1 (LGI1)‐IgG associated and contactin‐associated protein‐like 2 (CASPR2)‐IgG associated encephalitis. We performed the first randomized double‐blind placebo‐controlled trial to evaluate efficacy of intravenous immunoglobulin (IVIG) in reducing seizure frequency. Methods Our enrollment goal was 30 LGI1/CASPR2‐IgG–seropositive adult patients with ≥2 seizures per week. Patients were randomized to receive IVIG (0.5g/kg day 1, 1g/kg day 2, 0.6g/kg weeks 3 and 5) or volume‐matched intravenous normal saline. Following the blinded phase, the nonresponders in the placebo group received IVIG. The primary clinical outcome was 50% reduction in seizure frequency from baseline to 5 weeks. Results After enrollment of 17 patients (LGI1‐IgG, 14; CASPR2‐IgG, 3) over 34 months, the study was terminated due to slow enrollment. Six of 8 patients in the IVIG group were responders, compared to 2 of 9 in the placebo group (p = 0.044, odds ratio = 10.5, 95% confidence interval = 1.1–98.9). For the LGI1‐IgG seropositive subgroup, 6 of 8 patients in the IVIG group were responders, compared to zero of 6 in the placebo group. Two LGI1‐IgG–seropositive patients receiving IVIG, but none receiving placebo, were seizure‐free at the end of the blinded phase. Four of the 6 patients entering the open‐label IVIG arm reported ≥50% reduction in seizure frequency. There were no correlations with LGI1/CASPR2‐IgG1–4 subclasses. Interpretation Superiority of IVIG to placebo reached statistical significance for the primary endpoint for all patients and the subset with LGI1‐IgG. These results have to be interpreted with the caveat that the study did not reach its originally selected sample size. ANN NEUROL 2020;87:313–323
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Affiliation(s)
- Divyanshu Dubey
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Jeffrey Britton
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Andrew McKeon
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Avi Gadoth
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Anastasia Zekeridou
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Sebastian A Lopez Chiriboga
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Michelle Devine
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Jane H Cerhan
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN
| | - Katie Dunlay
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Jessica Sagen
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
| | - Melanie Ramberger
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Patrick Waters
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sean J Pittock
- Department of Neurology and Immunology, Mayo Clinic, Rochester, MN.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.,Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, MN
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Farmakidis C, Dimachkie MM, Pasnoor M, Barohn RJ. Immunosuppressive and immunomodulatory therapies for neuromuscular diseases. Part I: Traditional agents. Muscle Nerve 2019; 61:5-16. [DOI: 10.1002/mus.26708] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 09/05/2019] [Accepted: 09/07/2019] [Indexed: 12/23/2022]
Affiliation(s)
| | - Mazen M. Dimachkie
- Neurology Department University of Kansas Medical Center Kansas City Kansas
| | - Mamatha Pasnoor
- Neurology Department University of Kansas Medical Center Kansas City Kansas
| | - Richard J. Barohn
- Neurology Department University of Kansas Medical Center Kansas City Kansas
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Hehir MK, Silvestri NJ. Generalized Myasthenia Gravis: Classification, Clinical Presentation, Natural History, and Epidemiology. Neurol Clin 2019; 36:253-260. [PMID: 29655448 DOI: 10.1016/j.ncl.2018.01.002] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Myasthenia gravis (MG) is a rare disease, but the most common disorder of the neuromuscular junction. It is the prototypic autoimmune disease most commonly caused by antibodies to the acetylcholine receptor (AChR) leading to characteristic fatigable weakness of the ocular, bulbar, respiratory, axial, and limb muscles. The majority of patients with MG first present with ocular symptoms. Most patients with MG will experience at least 1 exacerbation of symptoms throughout the course of their illness. This article will cover the epidemiology, clinical presentation, classification, and natural history of MG.
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Affiliation(s)
- Michael K Hehir
- Department of Neurosciences, Larner College of Medicine at the University of Vermont, University of Vermont, 1 South Prospect Street, Burlington, VT 05401, USA.
| | - Nicholas J Silvestri
- Department of Neurology, University at Buffalo Jacobs School of Medicine & Biomedical Sciences, 1010 Main Street, Buffalo, New York 14202, USA
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31
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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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32
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Abstract
This article discusses antibodies associated with immune-mediated myasthenia gravis and the pathologic action of these antibodies at the neuromuscular junctions of skeletal muscle. To explain how these antibodies act, we consider the physiology of neuromuscular transmission with emphasis on 4 features: the structure of the neuromuscular junction; the roles of postsynaptic acetylcholine receptors and voltage-gated Na+ channels and in converting the chemical signal from the nerve terminal into a propagated action potential on the muscle fiber that triggers muscle contraction; the safety factor for neuromuscular transmission; and how the safety factor is reduced in different forms of autoimmune myasthenia gravis.
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Affiliation(s)
- Robert L Ruff
- Department of Neurology, Case Western University School of Medicine, The Metro Health System, 2500 Metro Health Drive, Cleveland, OH 44109, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Robert P Lisak
- Department of Neurology, Wayne State University School of Medicine, 8D University Health Center, 4201 St Antoine, Detroit, MI 48201, USA; Department of Biochemistry, Microbiology and Immunology, Wayne State University, Detroit, MI, USA.
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33
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Abstract
Myasthenia gravis (MG) diagnosis is primarily clinically based. By the end of the clinical evaluation, clinicians have a sense as to whether presenting symptoms and elicited signs are weakly or strongly supportive of MG. Diagnostic tests can reaffirm the clinicians' impression. Edrophonium testing is rarely used but helpful in cases of measurable ptosis. Decremental response on slow-frequency repetitive nerve stimulation has a modest diagnostic yield in ocular MG but is helpful in generalized MG cases. The most sensitive test is single-fiber electromyography. In this article, the authors review the diagnostic testing approach of practicing clinicians for suspected MG cases.
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Affiliation(s)
- Mamatha Pasnoor
- Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA.
| | - Mazen M Dimachkie
- Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA
| | - Constantine Farmakidis
- Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA
| | - Richard J Barohn
- Department of Neurology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA
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34
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Abstract
Neuromuscular junctions (NMJs) form between nerve terminals of spinal cord motor neurons and skeletal muscles, and perisynaptic Schwann cells and kranocytes cap NMJs. One muscle fiber has one NMJ, which is innervated by one motor nerve terminal. NMJs are excitatory synapses that use P/Q-type voltage-gated calcium channels to release the neurotransmitter acetylcholine. Acetylcholine receptors accumulate at the postsynaptic specialization called the end plate on the muscle fiber membrane, the sarcolemma. Proteins essential for the organization of end plates include agrin secreted from nerve terminals, Lrp4 and MuSK receptors for agrin, and Dok-7 and rapsyn cytosolic proteins in the muscle.
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Affiliation(s)
- Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, 3901 Rainbow Boulevard, MS 3051, Hemenway Room 2073, Kansas City, KS 66160, USA.
| | - Kazuhiro Shigemoto
- Research Team for Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology, Sakae-cho 35-2, Itabashi-ku, Tokyo 173-0015, Japan
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35
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Abstract
With specialized care, patients with myasthenia gravis can have very good outcomes. The mainstays of treatment are acetylcholinesterase inhibitors, and immunosuppressive and immunomodulatory therapies. There is good evidence thymectomy is beneficial in thymomatous and nonthymomatous disease. Nearly all of the drugs used for MG are considered "off-label." The 2 exceptions are acetylcholinesterase inhibitors and complement inhibition with eculizumab, which was recently approved by the US Food and Drug Administration for myasthenia gravis. This article reviews the evidence base and provides a framework for the treatment of myasthenia gravis, highlighting recent additions to the literature.
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36
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Nagappa M, Mahadevan A, Gangadhar Y, Patil SA, Bokolia S, Bindu PS, Sinha S, Taly AB. Autoantibodies in acquired myasthenia gravis: Clinical phenotype and immunological correlation. Acta Neurol Scand 2019; 139:428-437. [PMID: 30693486 DOI: 10.1111/ane.13071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 12/25/2018] [Accepted: 01/04/2019] [Indexed: 12/26/2022]
Abstract
BACKGROUND Data on antibody profile in myasthenia gravis (MG) from India are limited. OBJECTIVES To investigate antibody profile in patients with MG and their clinical correlates. PATIENTS AND METHODS Patients of MG (n = 85, M:F::1.1:1, mean age: 39.29 ± 17.3 years, mean symptom duration: 72.94 ± 91.8 months) were evaluated for clinical features, MG foundation of America (MGFA) score, response to treatment, and outcome at last follow-up. Antibodies to acetylcholine receptor (AChR), muscle-specific kinase (MUSK), titin and ryanodine receptor (RYR) were analysed using ELISA. RESULTS Based on the regional distribution of weakness, the cohort could be categorized as: generalized: 60, ocular: 16 and oculo-bulbar: 9. Sixty patients were followed up for a mean duration of 26.74 ± 13.8 months. Outcome at last follow-up was as follows: remission-22, no remission-33 and dead-5. AChR and MUSK antibodies were detected in 58 and 8 patients, respectively. Frequency of generalized MG, worse MGFA score during the disease course and thymomatous histology significantly correlated with presence of AChR-antibodies, though outcome at last follow-up was comparable between AChR-antibody positive and negative groups. Patients with MUSK antibodies had oculo-bulbar or generalized MG and frequent respiratory crisis, but majority improved or remitted with treatment. Titin antibodies were detected in 31.8% and RYR antibodies in 32.9%. Their presence did not correlate with age at onset of MG, severity or presence of thymoma. CONCLUSION This report highlights the spectrum of antibodies in MG in an Indian cohort. AChR-antibody positivity correlated with clinical severity. Outcome was good in majority of MUSK antibody-positive MG. The role of other antibodies, complementary vs epiphenomenon, remains open.
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Affiliation(s)
- Madhu Nagappa
- Department of Neurology National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
- Neuromuscular Laboratory (NML) Neurobiology Research Centre (NBRC) National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
| | - Anita Mahadevan
- Neuromuscular Laboratory (NML) Neurobiology Research Centre (NBRC) National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
- Department of Neuropathology National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
| | - Yashwanth Gangadhar
- Neuromuscular Laboratory (NML) Neurobiology Research Centre (NBRC) National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
- Department of Neuropathology National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
| | - Shripad A. Patil
- Department of Neuromicrobiology National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
| | - Suresh Bokolia
- Department of Neuromicrobiology National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
| | - Parayil S. Bindu
- Department of Neurology National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
- Neuromuscular Laboratory (NML) Neurobiology Research Centre (NBRC) National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
| | - Sanjib Sinha
- Department of Neurology National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
| | - Arun B. Taly
- Department of Neurology National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
- Neuromuscular Laboratory (NML) Neurobiology Research Centre (NBRC) National Institute of Mental Health and Neurosciences (NIMHANS) Bangalore India
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37
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Weger S, Appendino JP, Clark IH. Longstanding and Refractory Anti-Muscle Specific Tyrosine Kinase Antibody-Associated Myasthenia Gravis (Anti-MuSK-MG) in a Child Successfully Treated with Rituximab. J Binocul Vis Ocul Motil 2019; 69:26-29. [PMID: 30811277 DOI: 10.1080/2576117x.2019.1578164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Anti-muscle specific tyrosine kinase antibody-associated myasthenia gravis (MuSK-MG) is a rare subtype of MG characterized by more frequent relapses and a clinical course that is refractory to standard treatments. Rituximab, a monoclonal antibody targeting CD20+ B cells, has been used effectively in the adult population to achieve stable remission. We describe a pediatric patient with MuSK-MG who demonstrated an excellent response to rituximab after failing standard therapy.
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Affiliation(s)
- Steven Weger
- a Rady Faculty of Health Sciences, Max Rady College of Medicine , University of Manitoba , Winnipeg , MB , Canada
| | - Juan Pablo Appendino
- b Department of Paediatrics, Alberta Children's Hospital , University of Calgary , Calgary , AB , Canada.,c Cumming School of Medicine , University of Calgary , Calgary , AB , Canada
| | - Ian H Clark
- d Section of Pediatric Ophthalmology, Children's Hospital , University of Manitoba , Winnipeg , MB , Canada.,e Department of Ophthalmology, Max Rady College of Medicine, Rady Faculty of Health Sciences , University of Manitoba , Winnipeg , MB , Canada
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38
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Kushlaf H, Li Y. The evidence is stacked against thymectomy in MuSK myasthenia gravis. Muscle Nerve 2019; 59:393-394. [PMID: 30701589 DOI: 10.1002/mus.26439] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 01/26/2019] [Accepted: 01/28/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Hani Kushlaf
- Department of Neurology and Rehabilitation Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Yuebing Li
- Neuromuscular Center, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Desk S90, Cleveland, Ohio 44195, USA
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Clifford KM, Hobson-Webb LD, Benatar M, Burns TM, Barnett C, Silvestri NJ, Howard JF, Visser A, Crum BA, Nowak R, Beekman R, Kumar A, Ruzhansky K, Chen IHA, Pulley MT, Laboy SM, Fellman MA, Howard DB, Kolb NA, Greene SM, Pasnoor M, Dimachkie MM, Barohn RJ, Hehir MK. Thymectomy may not be associated with clinical improvement in MuSK myasthenia gravis. Muscle Nerve 2019; 59:404-410. [PMID: 30575980 DOI: 10.1002/mus.26404] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 11/24/2018] [Accepted: 12/16/2018] [Indexed: 12/20/2022]
Abstract
INTRODUCTION A randomized trial demonstrated benefit from thymectomy in nonthymomatous acetylcholine receptor (AChR)-antibody positive myasthenia gravis (MG). Uncontrolled observational and histologic studies suggest thymectomy may not be efficacious in anti-muscle-specific kinase (MuSK)-MG. METHODS The therapeutic impact of thymectomy was evaluated from data collected for a multicenter, retrospective blinded review of rituximab in MuSK-MG. RESULTS Baseline characteristics were similar between thymectomy (n = 26) and nonthymectomy (n = 29) groups, including treatment with rituximab (42% vs. 45%). At last visit, 35% of thymectomy subjects reached the primary endpoint, a Myasthenia Gravis Foundation of America (MGFA) post-intervention status (PIS) score of minimal manifestations (MM) or better, compared with 55% of controls (P = 0.17). After controlling for age at onset of MG, rituximab, prednisone, and intravenous immunoglobulin/plasma exchange treatment, thymectomy was not associated with greater likelihood of favorable clinical outcome (odds ratio = 0.43, 95% confidence interval 0.12-1.53, P = 0.19). DISCUSSION Thymectomy was not associated with additional clinical improvement in this multicenter cohort of MuSK-MG patients. Muscle Nerve 59:404-410, 2019.
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Affiliation(s)
- Katherine M Clifford
- Larner College of Medicine, University of Vermont, 1 South Prospect Street, Burlington, Vermont 05401, USA
| | - Lisa D Hobson-Webb
- Department of Neurology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Michael Benatar
- Department of Neurology, University of Miami Health System, Miami, Florida, USA
| | - Ted M Burns
- Department of Neurology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Carolina Barnett
- Department of Neurology, University of Toronto School of Medicine, Toronto, Ontario, Canada
| | - Nicholas J Silvestri
- Department of Neurology, University at Buffalo Jacobs School of Medicine & Biomedical Sciences, Buffalo, New York, USA
| | - James F Howard
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
| | - Amy Visser
- Department of Neurology, Oregon Health & Science University, Portland, Oregon, USA
| | - Brian A Crum
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Richard Nowak
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Rachel Beekman
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Aditya Kumar
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Katherine Ruzhansky
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - I-Hweii Amy Chen
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Michael T Pulley
- Department of Neurology, University of Florida, Jacksonville, Florida, USA
| | - Shannon M Laboy
- Department of Neurology, University of Florida, Jacksonville, Florida, USA
| | - Melissa A Fellman
- Department of Neurology, University of Miami Health System, Miami, Florida, USA
| | - Diantha B Howard
- Larner College of Medicine, University of Vermont, 1 South Prospect Street, Burlington, Vermont 05401, USA
| | - Noah A Kolb
- Larner College of Medicine, University of Vermont, 1 South Prospect Street, Burlington, Vermont 05401, USA
| | - Shane M Greene
- Larner College of Medicine, University of Vermont, 1 South Prospect Street, Burlington, Vermont 05401, USA
| | - Mamatha Pasnoor
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Mazen M Dimachkie
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Richard J Barohn
- Department of Neurology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Michael K Hehir
- Larner College of Medicine, University of Vermont, 1 South Prospect Street, Burlington, Vermont 05401, USA
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Bonanno S, Pasanisi MB, Frangiamore R, Maggi L, Antozzi C, Andreetta F, Campanella A, Brenna G, Cottini L, Mantegazza R. Amifampridine phosphate in the treatment of muscle-specific kinase myasthenia gravis: a phase IIb, randomized, double-blind, placebo-controlled, double crossover study. SAGE Open Med 2018; 6:2050312118819013. [PMID: 30574306 PMCID: PMC6299310 DOI: 10.1177/2050312118819013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/21/2018] [Indexed: 11/16/2022] Open
Abstract
Objective: The aim of this study is to determine the safety and the efficacy of amifampridine phosphate in muscle-specific kinase antibody-positive myasthenia gravis, in a 1:1 randomized, double-blind, placebo-controlled, switchback, double crossover study. Methods: Eligible patients had muscle-specific kinase myasthenia gravis, >18 years of age, and Myasthenia Gravis Foundation of America class II–IV with a score of ⩾9 on Myasthenia Gravis Composite scale. After the run-in phase, during which amifampridine phosphate was titrated to a tolerable and effective dosage, patients were randomized to receive placebo–amifampridine–placebo sequence or amifampridine–placebo–amifampridine sequence daily for 7 days. Then, patients switched treatment arms twice, for a total of 21 days of double-blind treatment. Safety was determined by serial assessments of adverse events/serious adverse events, physical examinations, and clinical and laboratory tests. The co-primary outcome measures included changes from baseline of Quantitative Myasthenia Gravis score and Myasthenia Gravis–specific Activities of Daily Living Profile score. The secondary outcome measures comprised changes from baseline of Myasthenia Gravis Composite score, Myasthenia Gravis Quality of Life scale—15 questions, Fatigue Severity Scale, and Carlo Besta Neurological Institute–Myasthenia Gravis scale. Statistical analyses were assessed using a switchback model for three-period, two-treatment crossover design. Results: A total of 10 patients were screened, enrolled, and treated. Transient paresthesias (60%) were the only amifampridine phosphate–related adverse events reported. Four patients were randomized to receive placebo–amifampridine–placebo sequence and three patients to receive amifampridine–placebo–amifampridine sequence. The co-primary objectives were statistically met (Quantitative Myasthenia Gravis score: p = 0.0003 and Myasthenia Gravis–specific Activities of Daily Living Profile score: p = 0.0006), as well as all the secondary endpoints (Myasthenia Gravis Composite score: p < 0.0001, Myasthenia Gravis Quality of Life scale—15 questions: p = 0.0025, Fatigue Severity Scale: p = 0.0061, and Carlo Besta Neurological Institute–Myasthenia Gravis scale: p = 0.0014). Conclusion: Despite the low number of patients, MuSK-001 study provided evidence that amifampridine phosphate, in the range of 30–60 mg daily dose, was safe and effective in treating muscle-specific kinase myasthenia gravis, suggesting the need for a large multi-center trial to confirm these results.
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Affiliation(s)
- Silvia Bonanno
- Department of Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy
| | - Maria Barbara Pasanisi
- Department of Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy
| | - Rita Frangiamore
- Department of Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy
| | - Lorenzo Maggi
- Department of Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy
| | - Carlo Antozzi
- Department of Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy
| | - Francesca Andreetta
- Department of Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy
| | - Angela Campanella
- Department of Clinical Research and Innovation, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy
| | | | | | - Renato Mantegazza
- Department of Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy.,Department of Clinical Research and Innovation, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta (INCB), Milan, Italy
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Deguchi K, Matsuzono K, Nakano Y, Kono S, Sato K, Deguchi S, Tanabe K, Hishikawa N, Ota Y, Yamashita T, Ohta K, Motomura M, Abe K. Anti-MuSK Antibody-positive Myasthenia Gravis Successfully Treated with Outpatient Periodic Weekly Blood Purification Therapy. Intern Med 2018; 57:1455-1458. [PMID: 29321424 PMCID: PMC5995714 DOI: 10.2169/internalmedicine.9466-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A 37-year-old man with anti-muscle-specific tyrosine kinase (MuSK) antibody-positive myasthenia gravis (MG) presented with subacute progressive dysphagia and muscle weakness of the neck and bilateral upper extremities. Conventional immune-suppressive treatments and high-dose intravenous immunoglobulin were ineffective. He then displayed repeated exacerbations and remissions over the course of two years, despite two to four sessions of plasma exchange (PE) every two months. The patient was successfully treated with outpatient periodic weekly blood purification therapy with alternative PE and double-filtration plasmapheresis using an internal shunt. This case report suggests the benefits of blood purification therapy with an internal shunt against anti-MuSK antibody-positive MG.
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Affiliation(s)
- Kentaro Deguchi
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Kosuke Matsuzono
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Yumiko Nakano
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Syoichiro Kono
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Kota Sato
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Shoko Deguchi
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Katsuyuki Tanabe
- Department of Nephrology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Nozomi Hishikawa
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Yasuyuki Ota
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Toru Yamashita
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
| | - Kiyoe Ohta
- Clinical Research Center, National Hospital Organization Utano National Hospital, Japan
| | - Masakatsu Motomura
- Department of Neurology and Strokology, Nagasaki University Hospital, Japan
- Medical Engineering Course, Department of Engineering, Faculty of Engineering, Nagasaki Institute of Applied Science, Japan
| | - Koji Abe
- Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Japan
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42
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Morren J, Li Y. Myasthenia gravis with muscle-specific tyrosine kinase antibodies: A narrative review. Muscle Nerve 2018; 58:344-358. [DOI: 10.1002/mus.26107] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 02/09/2018] [Accepted: 02/18/2018] [Indexed: 12/14/2022]
Affiliation(s)
- John Morren
- Neuromuscular Center, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Desk S90; Cleveland Ohio 44195 USA
| | - Yuebing Li
- Neuromuscular Center, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Desk S90; Cleveland Ohio 44195 USA
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43
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Ghazanfari N, Trajanovska S, Morsch M, Liang SX, Reddel SW, Phillips WD. The mouse passive-transfer model of MuSK myasthenia gravis: disrupted MuSK signaling causes synapse failure. Ann N Y Acad Sci 2017; 1412:54-61. [DOI: 10.1111/nyas.13513] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/05/2017] [Accepted: 09/09/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Nazanin Ghazanfari
- Physiology and Bosch Institute; University of Sydney; Sydney New South Wales Australia
| | - Sofie Trajanovska
- Physiology and Bosch Institute; University of Sydney; Sydney New South Wales Australia
| | - Marco Morsch
- Physiology and Bosch Institute; University of Sydney; Sydney New South Wales Australia
- Department of Biomedical Sciences; Macquarie University; Sydney New South Wales Australia
| | - Simon X. Liang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences; Liaoning Medical University; Jinzhou China
| | - Stephen W. Reddel
- Department of Molecular Medicine; Concord Hospital; Sydney New South Wales Australia
| | - William D. Phillips
- Physiology and Bosch Institute; University of Sydney; Sydney New South Wales Australia
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44
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Barraud C, Desguerre I, Barnerias C, Gitiaux C, Boulay C, Chabrol B. Clinical features and evolution of juvenile myasthenia gravis in a French cohort. Muscle Nerve 2017; 57:603-609. [PMID: 28877546 DOI: 10.1002/mus.25965] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2017] [Indexed: 01/17/2023]
Abstract
INTRODUCTION In this study we determined the clinical, paraclinical, and treatment-related features of juvenile myasthenia gravis (JMG) as well as the clinical course in a cohort of French children. METHODS We conducted a retrospective study of 40 patients with JMG at 2 French pediatric neurology departments from April 2004 to April 2014. RESULTS Among the patients, 70% had generalized JMG, 52% had positive acetylcholine receptor antibodies, 8% had muscle-specific kinase antibodies, and 40% were seronegative. Treatment with acetylcholinesterase inhibitors was effective and sufficient in 47% of patients. The 6 patients with generalized JMG treated with rituximab and/or immunoadsorption showed improvement. Thirty percent of the patients required hospitalization in an intensive care unit during follow-up (mean 4.7 years). Remission without treatment occurred in 18% of patients. DISCUSSION As with adults, JMG has high morbidity, particularly among children with generalized symptoms, and rituximab should be considered early in the course of the disease as a second-line treatment. Muscle Nerve 57: 603-609, 2018.
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Affiliation(s)
- Coline Barraud
- APHM Service de Neuropédiatrie, Hôpital La Timone-Enfants, 264, Rue St Pierre Marseille, 13385, cedex 5, France
- Aix-Marseille Université, Marseille, France
| | - Isabelle Desguerre
- APHP Service de Neuropédiatrie, Hôpital Necker-Enfants Malades, Paris, France
- Université René Descartes, Paris, France
| | - Christine Barnerias
- APHP Service de Neuropédiatrie, Hôpital Necker-Enfants Malades, Paris, France
| | - Cyril Gitiaux
- Aix-Marseille Université, Marseille, France
- APHP Service de Neuropédiatrie, Hôpital Necker-Enfants Malades, Paris, France
| | - Christophe Boulay
- APHM Service de Neuropédiatrie, Hôpital La Timone-Enfants, 264, Rue St Pierre Marseille, 13385, cedex 5, France
- Aix-Marseille Université, Marseille, France
| | - Brigitte Chabrol
- APHM Service de Neuropédiatrie, Hôpital La Timone-Enfants, 264, Rue St Pierre Marseille, 13385, cedex 5, France
- Aix-Marseille Université, Marseille, France
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45
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Hehir MK, Hobson-Webb LD, Benatar M, Barnett C, Silvestri NJ, Howard JF, Howard D, Visser A, Crum BA, Nowak R, Beekman R, Kumar A, Ruzhansky K, Chen IHA, Pulley MT, LaBoy SM, Fellman MA, Greene SM, Pasnoor M, Burns TM. Rituximab as treatment for anti-MuSK myasthenia gravis: Multicenter blinded prospective review. Neurology 2017; 89:1069-1077. [PMID: 28801338 DOI: 10.1212/wnl.0000000000004341] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/22/2017] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To evaluate the efficacy of rituximab in treatment of anti-muscle-specific kinase (MuSK) myasthenia gravis (MG). METHODS This was a multicenter, blinded, prospective review, comparing anti-MuSK-positive patients with MG treated with rituximab to those not treated with rituximab. The primary clinical endpoint was the Myasthenia Gravis Status and Treatment Intensity (MGSTI), a novel outcome that combines the Myasthenia Gravis Foundation of America (MGFA) postintervention status (PIS) and the number and dosages of other immunosuppressant therapies used. A priori, an MGSTI of level ≤2 was used to define a favorable outcome. Secondary outcomes included modified MGFA PIS of minimal manifestations or better, mean/median prednisone dose, and mean/median doses of other immunosuppressant drugs. RESULTS Seventy-seven of 119 patients with anti-MuSK MG evaluated between January 1, 2005, and January 1, 2015, at 10 neuromuscular centers were selected for analysis after review of limited clinical data by a blinded expert panel. An additional 22 patients were excluded due to insufficient follow-up. Baseline characteristics were similar between the rituximab-treated patients (n = 24) and the controls (n = 31). Median follow-up duration was >3.5 years. At last visit, 58% (14/24) of rituximab-treated patients reached the primary outcome compared to 16% (5/31) of controls (p = 0.002). Number needed to treat for the primary outcome is 2.4. At last visit, 29% of rituximab-treated patients were taking prednisone (mean dose 4.5 mg/day) compared to 74% of controls (mean dose 13 mg/day) (p = 0.001 and p = 0.005). CLASSIFICATION OF EVIDENCE This study provides Class IV evidence that for patients with anti-MuSK MG, rituximab increased the probability of a favorable outcome.
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Affiliation(s)
- Michael K Hehir
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville.
| | - Lisa D Hobson-Webb
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Michael Benatar
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Carolina Barnett
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Nicholas J Silvestri
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - James F Howard
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Diantha Howard
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Amy Visser
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Brian A Crum
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Richard Nowak
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Rachel Beekman
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Aditya Kumar
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Katherine Ruzhansky
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - I-Hweii Amy Chen
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Michael T Pulley
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Shannon M LaBoy
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Melissa A Fellman
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Shane M Greene
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Mamatha Pasnoor
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
| | - Ted M Burns
- From the Larner College of Medicine at the University of Vermont (M.K.H., D.H., S.M.G.), Burlington; Duke University School of Medicine (L.D.H.-W.), Durham, NC; University of Miami Health System (M.B., M.A.F.), FL; University of Toronto School of Medicine (C.B.), Canada; SUNY Buffalo Jacobs School of Medicine (N.J.S.), NY; UNC School of Medicine (J.F.H.), Chapel Hill, NC; Mayo Clinic (A.V., B.A.C.), Rochester, MN; Yale School of Medicine (R.N., R.B., A.K.), New Haven, CT; Medical University of South Carolina (K.R., I.-H.A.C.), Columbia; University of Florida (M.T.P., S.M.L., Gainesville; University of Kansas Medical Center (M.P.), Kansas City; and University of Virginia School of Medicine (T.M.B.), Charlottesville
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Gungor-Tuncer O, Yilmaz V, Toker A, Saruhan-Direskeneli G, Gulsen-Parman Y, Oflazer-Serdaroglu P, Deymeer F. Prompt Response to Prednisone Predicts Benign Course in MuSK-MG. Eur Neurol 2017; 78:137-142. [DOI: 10.1159/000479228] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/04/2017] [Indexed: 11/19/2022]
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Kim SW, Sunwoo MK, Kim SM, Shin HY, Sunwoo IN. Repetitive Nerve Stimulation in MuSK-Antibody-Positive Myasthenia Gravis. J Clin Neurol 2017; 13:287-292. [PMID: 28516744 PMCID: PMC5532326 DOI: 10.3988/jcn.2017.13.3.287] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/09/2017] [Accepted: 03/09/2017] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Responses to repetitive nerve stimulation (RNS) in patients with muscle-specific tyrosine kinase (MuSK) antibody (Ab)-positive myasthenia gravis (MG) vary depending on the muscles tested. We analyzed the RNS responses of limb and facial muscles in MuSK-Ab-positive and acetylcholine receptor (AChR)-Ab-negative MG (MuSK MG) and MuSK-Ab-negative and AChR-Ab-negative [double-seronegative (DSN)] MG patients. METHODS We retrospectively compared RNS responses between 45 MuSK MG and 29 DSN MG. RNS was applied to the abductor digiti minimi, flexor carpi ulnaris, trapezius, orbicularis oculi, and nasalis muscles. RESULTS Abnormal RNS responses in limb muscles were observed in 22.2 and 58.6% of MuSK MG and DSN MG patients, respectively, with abnormal facial responses observed in 77.8 and 65.5%, and abnormal responses observed in any of the five muscles in 86.7 and 72.4%. Abnormal RNS responses in the abductor digiti minimi or flexor carpi ulnaris were less frequent in MuSK MG (8.9 and 15.6%, respectively) than in DSN MG (37.9 and 55.2%), whereas the findings for other muscles were not significantly different between the groups. Abnormal facial responses but normal limb responses were independently associated with MuSK MG (odds ratio=5.224, 95% confidence interval=1.300-20.990). CONCLUSIONS Abnormal RNS responses primarily in facial muscles without involvement of limb muscles were more pronounced in MuSK MG than in DSN MG. RNS of both facial and limb muscles in AChR-Ab-negative MG can increase the test sensitivity and aid in early suspicion of MuSK MG.
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Affiliation(s)
- Seung Woo Kim
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
| | - Mun Kyung Sunwoo
- Department of Neurology, Bundang Jesaeng General Hospital, Seongnam, Korea
| | - Seung Min Kim
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
| | - Ha Young Shin
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
| | - Il Nam Sunwoo
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
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48
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Perez EE, Orange JS, Bonilla F, Chinen J, Chinn IK, Dorsey M, El-Gamal Y, Harville TO, Hossny E, Mazer B, Nelson R, Secord E, Jordan SC, Stiehm ER, Vo AA, Ballow M. Update on the use of immunoglobulin in human disease: A review of evidence. J Allergy Clin Immunol 2016; 139:S1-S46. [PMID: 28041678 DOI: 10.1016/j.jaci.2016.09.023] [Citation(s) in RCA: 376] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 09/12/2016] [Accepted: 09/23/2016] [Indexed: 12/20/2022]
Abstract
Human immunoglobulin preparations for intravenous or subcutaneous administration are the cornerstone of treatment in patients with primary immunodeficiency diseases affecting the humoral immune system. Intravenous preparations have a number of important uses in the treatment of other diseases in humans as well, some for which acceptable treatment alternatives do not exist. We provide an update of the evidence-based guideline on immunoglobulin therapy, last published in 2006. Given the potential risks and inherent scarcity of human immunoglobulin, careful consideration of its indications and administration is warranted.
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Affiliation(s)
- Elena E Perez
- Allergy Associates of the Palm Beaches, North Palm Beach, Fla.
| | - Jordan S Orange
- Department of Pediatrics, Section of Immunology Allergy and Rheumatology, Center for Human Immunobiology, Texas Children's Hospital and Baylor College of Medicine, Houston, Tex
| | - Francisco Bonilla
- Department of Pediatrics, Clinical Immunology Program, Children's Hospital Boston and Harvard Medical School, Boston, Mass
| | - Javier Chinen
- Department of Pediatrics, Section of Immunology Allergy and Rheumatology, Center for Human Immunobiology, Texas Children's Hospital and Baylor College of Medicine, Houston, Tex
| | - Ivan K Chinn
- Department of Pediatrics, Section of Immunology Allergy and Rheumatology, Center for Human Immunobiology, Texas Children's Hospital and Baylor College of Medicine, Houston, Tex
| | - Morna Dorsey
- Department of Pediatrics, Allergy, Immunology and BMT Division, Benioff Children's Hospital and University of California, San Francisco, Calif
| | - Yehia El-Gamal
- Department of Pediatrics, Pediatric Allergy and Immunology Unit, Children's Hospital and Ain Shams University, Cairo, Egypt
| | - Terry O Harville
- Departments of Pathology and Laboratory Services and Pediatrics, University of Arkansas, Little Rock, Ark
| | - Elham Hossny
- Department of Pediatrics, Pediatric Allergy and Immunology Unit, Children's Hospital and Ain Shams University, Cairo, Egypt
| | - Bruce Mazer
- Department of Pediatrics, Allergy and Immunology, Montreal Children's Hospital and McGill University, Montreal, Quebec, Canada
| | - Robert Nelson
- Department of Medicine and Pediatrics, Division of Hematology and Oncology and Stem Cell Transplantation, Riley Hospital, Indiana University School of Medicine and the IU Melvin and Bren Simon Cancer Center, Indianapolis, Ind
| | - Elizabeth Secord
- Department of Pediatrics, Wayne State University, Children's Hospital of Michigan, Detroit, Mich
| | - Stanley C Jordan
- Nephrology & Transplant Immunology, Kidney Transplant Program, David Geffen School of Medicine at UCLA and Cedars-Sinai Medical Center, Los Angeles, Calif
| | - E Richard Stiehm
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, Calif
| | - Ashley A Vo
- Transplant Immunotherapy Program, Comprehensive Transplant Center, Kidney Transplant Program, Cedars-Sinai Medical Center, Los Angeles, Calif
| | - Mark Ballow
- Department of Pediatrics, Division of Allergy & Immunology, University of South Florida, Morsani College of Medicine, Johns Hopkins All Children's Hospital, St Petersburg, Fla
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49
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Appeltshauser L, Weishaupt A, Sommer C, Doppler K. Complement deposition induced by binding of anti-contactin-1 auto-antibodies is modified by immunoglobulins. Exp Neurol 2016; 287:84-90. [PMID: 27746185 DOI: 10.1016/j.expneurol.2016.10.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 10/07/2016] [Accepted: 10/13/2016] [Indexed: 01/30/2023]
Abstract
Inflammatory neuropathies associated with auto-antibodies against paranodal proteins like contactin-1 are reported to respond poorly to treatment with intravenous immunoglobulins (IVIG). A reason might be that IVIG interacts with the complement pathway and these auto-antibodies often belong to the IgG4 subclass that does not activate complement. However, some patients do show a response to IVIG, especially at the beginning of the disease. This corresponds with the finding of coexisting IgG subclasses IgG1, IgG2 and IgG3. We therefore aimed to investigate complement deposition and activation by samples of three patients with anti-contactin-1 IgG auto-antibodies of different subclasses as a potential predictor for response to IVIG. Complement deposition and activation was measured by cell binding and ELISA based assays, and the effect of IVIG on complement deposition was assessed by addition of different concentrations of IVIG. Binding of anti-contactin-1 auto-antibodies of all three patients induced complement deposition and activation with the strongest effect shown by the serum of a patient with predominance of IgG3 auto-antibodies. IVIG led to a reduction of complement deposition in a dose-dependent manner, but did not reduce binding of auto-antibodies to contactin-1. We conclude that complement deposition may contribute to the pathophysiology of anti-contactin-1 associated neuropathy, particularly in patients with predominance of the IgG3 subclass. The proportion of different auto-antibody subclasses may be a predictor for the response to IVIG in patients with auto-antibodies against paranodal proteins.
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Affiliation(s)
- Luise Appeltshauser
- Department of Neurology, University Hospital of Würzburg, Josef-Schneider-Str. 11, 97080 Würzburg, Germany
| | - Andreas Weishaupt
- Department of Neurology, University Hospital of Würzburg, Josef-Schneider-Str. 11, 97080 Würzburg, Germany
| | - Claudia Sommer
- Department of Neurology, University Hospital of Würzburg, Josef-Schneider-Str. 11, 97080 Würzburg, Germany
| | - Kathrin Doppler
- Department of Neurology, University Hospital of Würzburg, Josef-Schneider-Str. 11, 97080 Würzburg, Germany.
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50
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Maintenance immunosuppression in myasthenia gravis. J Neurol Sci 2016; 369:294-302. [DOI: 10.1016/j.jns.2016.08.057] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 07/20/2016] [Accepted: 08/26/2016] [Indexed: 11/17/2022]
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