1
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Le Panse R. Is there a path to cure myasthenia gravis? Curr Opin Immunol 2025; 95:102577. [PMID: 40449041 DOI: 10.1016/j.coi.2025.102577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2025] [Accepted: 05/15/2025] [Indexed: 06/02/2025]
Abstract
Myasthenia gravis (MG) is an autoimmune disorder characterized by muscle fatigability caused by autoantibodies targeting components of the neuromuscular junction, primarily the acetylcholine receptor (AChR). In AChR-MG, the thymus plays a central role as the initiating site of sensitization, fostering a highly inflammatory environment that supports the production of autoreactive T and B cells. Current treatments mainly focus on symptom relief and broad immunosuppressive therapies but fall short of providing a definitive cure. This review examines the pathophysiological mechanisms underlying MG and discusses emerging therapeutic strategies aiming to achieve long-term remission or even a cure. By combining targeted elimination of autoreactive cell sources through thymectomy in AChR-MG with strategies to reset and restore immune tolerance, we may be on the path to a true cure for this complex autoimmune disorder.
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Affiliation(s)
- Rozen Le Panse
- Sorbonne University, INSERM, Association Institute of Myology, Center of Research in Myology, UMRS 974, Paris, France.
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2
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Michailidou I, Patsiarika A, Kesidou E, Boziki MK, Parisis D, Bakirtzis C, Chroni E, Grigoriadis N. The role of complement in the immunopathogenesis of acetylcholine receptor antibody-positive generalized myasthenia gravis: bystander or key player? Front Immunol 2025; 16:1526317. [PMID: 40303417 PMCID: PMC12037622 DOI: 10.3389/fimmu.2025.1526317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2024] [Accepted: 03/24/2025] [Indexed: 05/02/2025] Open
Abstract
The complement system is a key component of the innate immune system. In antiacetylcholine receptor (AChR) antibody-positive (Ab+) generalized myasthenia gravis (MG), complement activation has long been considered a principal driver of pathology. Understanding the role of complement in AChR-Ab+ generalized MG has gained increasing importance in recent years, as anticomplement drugs have been approved for clinical use or are undergoing phase II/III clinical trials. This review aims to discuss recent and previous findings on the role of complement in AChR-Ab+ MG pathology, including its interaction with pathogenic antibodies and mechanisms beyond the classical pathway activation.
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Affiliation(s)
- Iliana Michailidou
- Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Evangelia Kesidou
- Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Marina Kleopatra Boziki
- Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
- 2Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Dimitrios Parisis
- 2Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Christos Bakirtzis
- 2Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Elisabeth Chroni
- Department of Neurology, Medical School, University of Patras, Patra, Greece
| | - Nikolaos Grigoriadis
- Laboratory of Experimental Neurology and Neuroimmunology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
- 2Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
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3
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Binks SNM, Morse IM, Ashraghi M, Vincent A, Waters P, Leite MI. Myasthenia gravis in 2025: five new things and four hopes for the future. J Neurol 2025; 272:226. [PMID: 39987373 PMCID: PMC11846739 DOI: 10.1007/s00415-025-12922-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2024] [Revised: 01/20/2025] [Accepted: 01/22/2025] [Indexed: 02/24/2025]
Abstract
The last 10 years has brought transformative developments in the effective treatment of myasthenia gravis (MG). Beginning with the randomized trial of thymectomy in myasthenia gravis that demonstrated efficacy of thymectomy in nonthymomatous MG, several new treatment approaches have completed successful clinical trials and regulatory launch. These modalities, including B cell depletion, complement inhibition, and blockade of the neonatal Fc receptor, are now in use, offering prospects of sustained remission and neuromuscular protection in what is a long-term disease. In this review, we update our clinico-immunological review of 2016 with these important advances, examine their role in treatment algorithms, and focus attention on key issues of biomarkers for prognostication and the growing cohort of older patients, both those with long-term disease, and late-onset MG ('LOMG'). We close by expressing our four hopes for the next 5-10 years: improvements in laboratory medicine to facilitate rapid diagnosis, effective strategies for neuromuscular protection, more research into and better understanding of pathophysiology and treatment response in older individuals, and the potentially transformative role of therapies aimed at delivering a durable response such as chimeric antigen receptor (CAR) T cells. Our postscript summarizes some emerging themes in the field of serological and online biomarkers, which may develop greater stature in the next epoch.
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Affiliation(s)
- S N M Binks
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Department of Neurology, John Radcliffe Hospital, Oxford, UK
| | - I M Morse
- Medical Sciences Division, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Mohammad Ashraghi
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - A Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Medical Sciences Division, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Patrick Waters
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - M Isabel Leite
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
- Department of Neurology, John Radcliffe Hospital, Oxford, UK.
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4
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Avallone AR, Di Stefano V, Bevilacqua L, Alonge P, Lupica A, Maccora S, Monastero R, Amabile S, Barone P, Brighina F, Vinciguerra C. AChR-seropositive myasthenia gravis in muscular dystrophy: diagnostic pitfalls and clinical management challenges. Neurol Sci 2025; 46:125-132. [PMID: 38965114 DOI: 10.1007/s10072-024-07675-6] [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: 04/09/2024] [Accepted: 06/24/2024] [Indexed: 07/06/2024]
Abstract
The co-occurrence of genetic myopathies with myasthenia gravis (MG) is extremely rare, however a few studies have been reported. We aim to explore the link between genetically inherited muscle disorders and immune-mediated neuromuscular junction conditions, taking into account the diagnostic and therapeutic implications posed by these combined conditions. We searched all English medical papers registered in Web of Knowledge, PubMed, Google Scholar, and Science Direct between January 1987 concerning the association between muscular dystrophies (MD) and MG, also adding three new cases to the series reported so far. Three new clinical cases in which MG concurs with oculopharyngeal muscular dystrophy (OPMD) or facioscapulohumeral muscular dystrophy (FSHD) or myotonic dystrophy type 2 (DM2) were reported. A comprehensive literature review showed that FSHD is the dystrophy most frequently associated with generalized MG. The AChR antibody titer is high and neurophysiologic tests prove to be an essential tool for the diagnosis. The association between MG and MD is rare but should not be underestimated. The presence of unusual clinical features suggest investigating additional overlapping condition, especially when a treatable disease like MG is suspected.
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Affiliation(s)
- Anna Rosa Avallone
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University Hospital San Giovanni di Dio e Ruggi D'Aragona, University of Salerno, Salerno, 84131, Italy
| | - Vincenzo Di Stefano
- Department of Biomedicine, Neuroscience, and advanced Diagnostic (BiND), University of Palermo, Palermo, Italy
| | - Liliana Bevilacqua
- Department of Biomedicine, Neuroscience, and advanced Diagnostic (BiND), University of Palermo, Palermo, Italy
| | - Paolo Alonge
- Department of Biomedicine, Neuroscience, and advanced Diagnostic (BiND), University of Palermo, Palermo, Italy
| | - Antonino Lupica
- Department of Biomedicine, Neuroscience, and advanced Diagnostic (BiND), University of Palermo, Palermo, Italy
| | - Simona Maccora
- Department of Biomedicine, Neuroscience, and advanced Diagnostic (BiND), University of Palermo, Palermo, Italy
| | - Roberto Monastero
- Department of Biomedicine, Neuroscience, and advanced Diagnostic (BiND), University of Palermo, Palermo, Italy
| | - Sonia Amabile
- Medical Genomics Program, AOU S. Giovanni di Dio e Ruggi d'Aragona, University of Salerno, Salerno, Italy
| | - Paolo Barone
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University Hospital San Giovanni di Dio e Ruggi D'Aragona, University of Salerno, Salerno, 84131, Italy
| | - Filippo Brighina
- Department of Biomedicine, Neuroscience, and advanced Diagnostic (BiND), University of Palermo, Palermo, Italy
| | - Claudia Vinciguerra
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University Hospital San Giovanni di Dio e Ruggi D'Aragona, University of Salerno, Salerno, 84131, Italy.
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5
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Jacob S. Treating myasthenia gravis beyond the eye clinic. Eye (Lond) 2024; 38:2422-2436. [PMID: 38789789 PMCID: PMC11306738 DOI: 10.1038/s41433-024-03133-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/17/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024] Open
Abstract
Myasthenia gravis (MG) is one of the most well characterised autoimmune disorders affecting the neuromuscular junction with autoantibodies targeting the acetylcholine receptor (AChR) complex. The vast majority of patients present with ocular symptoms including double vision and ptosis, but may progress on to develop generalised fatiguable muscle weakness. Severe involvement of the bulbar muscles can lead to dysphagia, dysarthria and breathing difficulties which can progress to myasthenic crisis needing ventilatory support. Given the predominant ocular onset of the disease, it is important that ophthalmologists are aware of the differential diagnosis, investigations and management including evolving therapies. When the disease remains localised to the extraocular muscles (ocular MG) IgG1 and IgG3 antibodies against the AChR (including clustered AChR) are present in nearly 50% of patients. In generalised MG this is seen in nearly 90% patients. Other antibodies include those against muscle specific tyrosine kinase (MuSK) and lipoprotein receptor related protein 4 (LRP4). Even though decremental response on repetitive nerve stimulation is the most well recognised neurophysiological abnormality, single fibre electromyogram (SFEMG) in experienced hands is the most sensitive test which helps in the diagnosis. Initial treatment should be using cholinesterase inhibitors and then proceeding to immunosuppression using corticosteroids and steroid sparing drugs. Patients requiring bulbar muscle support may need rescue therapies including plasma exchange and intravenous immunoglobulin (IVIg). Newer therapeutic targets include those against the B lymphocytes, complement system, neonatal Fc receptors (FcRn) and various other elements of the immune system.
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Affiliation(s)
- Saiju Jacob
- University Hospitals Birmingham, Birmingham, UK.
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.
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6
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Tavasoli A. Immune mediated myasthenia gravis in children, current concepts and new treatments: A narrative review article. IRANIAN JOURNAL OF CHILD NEUROLOGY 2024; 18:21-42. [PMID: 38988843 PMCID: PMC11231678 DOI: 10.22037/ijcn.v18i3.45054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Accepted: 05/19/2024] [Indexed: 07/12/2024]
Abstract
Myasthenia gravis (MG) is the most frequent transmission disease in the neuromuscular junction. Juvenile myasthenia gravis (JMG) is an autoimmune antibody-mediated disease of postsynaptic endplate defined as MG presentation in patients before the age of 18 years old. While many clinical features of JMG are identical to the adults, there are some significant differences between them regarding presentation, clinical course, antibody level, and thymus histopathology. In JMG, ocular symptoms are more frequent, the clinical course is comparably benign, and the outcome is better than adult MG. Antibodies attack the muscle endplate proteins in the postsynaptic membrane and interfere with transmission. These antibodies in most patients are against the acetylcholine receptors, but they may also be directed toward muscle-specific kinase, lipoprotein-related protein 4, and agrin. Findings show racial influences and genetic effects on the occurrence of JMG. The essential clinical symptom is fatigable weakness of muscles that can be in the form of isolated ocular type or more disseminated weakness. The diagnosis of JMG is essentially clinical, with fluctuating patterns of weakness and easy fatigability, but a series of diagnostic evaluations can confirm the diagnosis. Precise diagnostic evaluation and distinction from congenital myasthenic syndromes is critical. The treatment plan is conducted according to the clinical course (ocular or generalized), antibody type, and disease severity. The mainstay of treatment includes symptomatic therapy, long-lasting immunosuppressive treatment and treatment of myasthenic crisis. Novel medications are introduced and conducted to the specific pathophysiologic mechanisms of the disease, and they are used primarily in the refractory MG.
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Affiliation(s)
- Azita Tavasoli
- Department of Pediatric Neurology , Iran University of Medical Sciences, Tehran, Iran
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7
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Kaminski HJ, Sikorski P, Coronel SI, Kusner LL. Myasthenia gravis: the future is here. J Clin Invest 2024; 134:e179742. [PMID: 39105625 DOI: 10.1172/jci179742] [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: 08/07/2024] Open
Abstract
Myasthenia gravis (MG) stands as a prototypical antibody-mediated autoimmune disease: it is dependent on T cells and characterized by the presence of autoantibodies targeting proteins located on the postsynaptic surface of skeletal muscle, known as the neuromuscular junction. Patients with MG exhibit a spectrum of weakness, ranging from limited ocular muscle involvement to life-threatening respiratory failure. Recent decades have witnessed substantial progress in understanding the underlying pathophysiology, leading to the delineation of distinct subcategories within MG, including MG linked to AChR or MuSK antibodies as well as age-based distinction, thymoma-associated, and immune checkpoint inhibitor-induced MG. This heightened understanding has paved the way for the development of more precise and targeted therapeutic interventions. Notably, the FDA has recently approved therapeutic inhibitors of complement and the IgG receptor FcRn, a testament to our improved comprehension of autoantibody effector mechanisms in MG. In this Review, we delve into the various subgroups of MG, stratified by age, autoantibody type, and histology of the thymus with neoplasms. Furthermore, we explore both current and potential emerging therapeutic strategies, shedding light on the evolving landscape of MG treatment.
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Affiliation(s)
| | | | | | - Linda L Kusner
- Department of Pharmacology and Physiology, George Washington University, Washington, DC, USA
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8
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Fenioux C, Abbar B, Boussouar S, Bretagne M, Power JR, Moslehi JJ, Gougis P, Amelin D, Dechartres A, Lehmann LH, Courand PY, Cautela J, Alexandre J, Procureur A, Rozes A, Leonard-Louis S, Qin J, Cheynier R, Charmeteau-De Muylder B, Redheuil A, Tubach F, Cadranel J, Milon A, Ederhy S, Similowski T, Johnson DB, Pizzo I, Catalan T, Benveniste O, Hayek SS, Allenbach Y, Rosenzwajg M, Dolladille C, Salem JE. Thymus alterations and susceptibility to immune checkpoint inhibitor myocarditis. Nat Med 2023; 29:3100-3110. [PMID: 37884625 DOI: 10.1038/s41591-023-02591-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 09/15/2023] [Indexed: 10/28/2023]
Abstract
Immune checkpoint inhibitors (ICI) have transformed the therapeutic landscape in oncology. However, ICI can induce uncommon life-threatening autoimmune T-cell-mediated myotoxicities, including myocarditis and myositis. The thymus plays a critical role in T cell maturation. Here we demonstrate that thymic alterations are associated with increased incidence and severity of ICI myotoxicities. First, using the international pharmacovigilance database VigiBase, the Assistance Publique Hôpitaux de Paris-Sorbonne University data warehouse (Paris, France) and a meta-analysis of clinical trials, we show that ICI treatment of thymic epithelial tumors (TET, and particularly thymoma) was more frequently associated with ICI myotoxicities than other ICI-treated cancers. Second, in an international ICI myocarditis registry, we established that myocarditis occurred earlier after ICI initiation in patients with TET (including active or prior history of TET) compared to other cancers and was more severe in terms of life-threatening arrythmias and concurrent myositis, leading to respiratory muscle failure and death. Lastly, we show that presence of anti-acetylcholine-receptor antibodies (a biological proxy of thymic-associated autoimmunity) was more prevalent in patients with ICI myocarditis than in ICI-treated control patients. Altogether, our results highlight that thymic alterations are associated with incidence and seriousness of ICI myotoxicities. Clinico-radio-biological workup evaluating the thymus may help in predicting ICI myotoxicities.
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Affiliation(s)
- Charlotte Fenioux
- Sorbonne Université, INSERM, CIC-1901 Paris-Est, Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Pharmacology, Paris, France
- Hôpitaux de Paris, Henri Mondor Hospital, Department of Oncology, Créteil, France
| | - Baptiste Abbar
- Sorbonne Université, INSERM, CIC-1901 Paris-Est, Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Pharmacology, Paris, France
- Hôpitaux de Paris, Pitié Salpêtrière Hospital, Department of Oncology, Paris, France
| | - Samia Boussouar
- Hôpitaux de Paris, Pitié Salpêtrière Hospital, Department of Radiology, Paris, France
| | - Marie Bretagne
- Sorbonne Université, INSERM, CIC-1901 Paris-Est, Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Pharmacology, Paris, France
| | - John R Power
- Department of Medecine, University of California, San Diego, San Diego, CA, USA
| | - Javid J Moslehi
- Department of Medecine, University of California, San Francisco, San Francisco, CA, USA
| | - Paul Gougis
- Sorbonne Université, INSERM, CIC-1901 Paris-Est, Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Pharmacology, Paris, France
| | - Damien Amelin
- Sorbonne Université, INSERM, Association Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
| | - Agnès Dechartres
- Sorbonne Université, INSERM, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Département de Santé Publique, Centre de Pharmacoépidémiologie (Cephepi), Unité de Recherche Clinique PSL-CFX, CIC-1901, AP-HP, Hôpital Pitié Salpêtrière, Paris, France
| | - Lorenz H Lehmann
- Department of Cardiology, University Hospital Heidelberg; German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Pierre-Yves Courand
- Fédération de Cardiologie, IMMUCARE, Hôpital de La Croix-Rousse Et Hôpital Lyon Sud, Hospices Civils de Lyon; Université de Lyon, CREATIS UMR INSERM U1044, INSA, Lyon, France
| | - Jennifer Cautela
- Aix-Marseille University, University Mediterranean Center of Cardio-Oncology, Unit of Heart Failure and Valvular Heart Diseases, Center for Cardiovascular and Nutrition Research, INSERM 1263, INRAE 1260, Nord Hospital, Assistance Publique-Hôpitaux de Marseille, Paris, France
| | - Joachim Alexandre
- CHU de Caen Normandie, Department of Pharmacology, Pharmacoepidemiology Unit; Normandie Université, UNICAEN, INSERM U1086 ANTICIPE Centre François Baclesse, Caen, France
| | - Adrien Procureur
- Sorbonne Université, INSERM, CIC-1901 Paris-Est, Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Pharmacology, Paris, France
| | - Antoine Rozes
- Sorbonne Université, INSERM, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Département de Santé Publique, Centre de Pharmacoépidémiologie (Cephepi), Unité de Recherche Clinique PSL-CFX, CIC-1901, AP-HP, Hôpital Pitié Salpêtrière, Paris, France
| | - Sarah Leonard-Louis
- Hôpitaux de Paris, Pitié Salpêtrière Hospital, Laboratoire de Neuropathologie, Paris, France
| | - Juan Qin
- Department of Medecine, University of California, San Francisco, San Francisco, CA, USA
| | - Rémi Cheynier
- Université Paris Cité, CNRS, INSERM, Institut Cochin, Paris, France
| | | | - Alban Redheuil
- Hôpitaux de Paris, Pitié Salpêtrière Hospital, Department of Radiology, Paris, France
| | - Florence Tubach
- Sorbonne Université, INSERM, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Département de Santé Publique, Centre de Pharmacoépidémiologie (Cephepi), Unité de Recherche Clinique PSL-CFX, CIC-1901, AP-HP, Hôpital Pitié Salpêtrière, Paris, France
| | - Jacques Cadranel
- Hôpitaux de Paris, Tenon Hospital, Department of Pulmonology and Thoracic Oncology and GRC Theranoscan Sorbonne University, Paris, France
| | - Audrey Milon
- Hôpitaux de Paris, Tenon Hospital, Department of Radiology, Paris, France
| | - Stéphane Ederhy
- Hôpitaux de Paris, Saint-Antoine Hospital, Department of Cardiology, Paris, France
| | - Thomas Similowski
- Sorbonne Université, INSERM, UMRS 1158 Neurophysiologie respiratoire expérimentale et clinique'; Assistance Publique -Hôpitaux de Paris, Pitié-Salpêtrière Hospital, 'Département R3S', Paris, France
| | - Douglas B Johnson
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ian Pizzo
- Department of Internal Medicine, Division of Cardiology, University of Michigan, Ann Arbor, MI, USA
| | - Toniemarie Catalan
- Department of Internal Medicine, Division of Cardiology, University of Michigan, Ann Arbor, MI, USA
| | - Olivier Benveniste
- Department of Internal Medicine, Sorbonne University, AP-HP, INSERM UMRS 974, Pitié-Salpêtrière Hospital, Paris, France
| | - Salim S Hayek
- Department of Internal Medicine, Division of Cardiology, University of Michigan, Ann Arbor, MI, USA
| | - Yves Allenbach
- Department of Internal Medicine, Sorbonne University, AP-HP, INSERM UMRS 974, Pitié-Salpêtrière Hospital, Paris, France
| | - Michelle Rosenzwajg
- Hôpitaux de Paris, Pitié Salpêtrière Hospital, Department of Immunology, Paris, France
| | - Charles Dolladille
- Sorbonne Université, INSERM, CIC-1901 Paris-Est, Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Pharmacology, Paris, France
| | - Joe-Elie Salem
- Sorbonne Université, INSERM, CIC-1901 Paris-Est, Assistance Publique - Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Department of Pharmacology, Paris, France.
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
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9
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Nair SS, Jacob S. Novel Immunotherapies for Myasthenia Gravis. Immunotargets Ther 2023; 12:25-45. [PMID: 37038596 PMCID: PMC10082579 DOI: 10.2147/itt.s377056] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 03/03/2023] [Indexed: 04/07/2023] Open
Abstract
Myasthenia gravis (MG), a prototype autoimmune neurological disease, had its therapy centred on corticosteroids, non-steroidal broad-spectrum immunotherapy and cholinesterase inhibitors for several decades. Treatment-refractory MG and long-term toxicities of the medications have been major concerns with the conventional therapies. Advances in the immunology and pathogenesis of MG have ushered in an era of newer therapies which are more specific and efficacious. Complement inhibitors and neonatal Fc receptor blockers target disease-specific pathogenic mechanisms linked to myasthenia and have proven their efficacy in pivotal clinical studies. B cell-depleting agents, specifically rituximab, have also emerged as useful for the treatment of severe MG. Many more biologicals are in the pipeline and in diverse stages of development. This review discusses the evidence for the novel therapies and the specific issues related to their clinical use.
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Affiliation(s)
- Sruthi S Nair
- Department of Neurology, University Hospitals Birmingham, Birmingham, B15 2TH, UK
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | - Saiju Jacob
- Department of Neurology, University Hospitals Birmingham, Birmingham, B15 2TH, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, B15 2TT, UK
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10
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Gong L, Tian J, Zhang W, Huang G. ASO Author Reflections: A Possible New Etiology of Thymoma-Associated Myasthenia Gravis-Human Parvovirus B19. Ann Surg Oncol 2023; 30:1656-1657. [PMID: 36542247 DOI: 10.1245/s10434-022-12958-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022]
Affiliation(s)
- Li Gong
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi'an, People's Republic of China
| | - Jing Tian
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi'an, People's Republic of China
| | - Wei Zhang
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi'an, People's Republic of China
| | - Gaosheng Huang
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi'an, People's Republic of China. .,State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Air Force Medical University, Xi'an, People's Republic of China.
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11
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Sikorski PM, Kusner LL, Kaminski HJ. Myasthenia Gravis. Clin Immunol 2023. [DOI: 10.1016/b978-0-7020-8165-1.00065-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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12
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Payet CA, You A, Fayet OM, Hemery E, Truffault F, Bondet V, Duffy D, Michel F, Fadel E, Guihaire J, Demeret S, Berrih-Aknin S, Le Panse R. Central Role of Macrophages and Nucleic Acid Release in Myasthenia Gravis Thymus. Ann Neurol 2022; 93:643-654. [PMID: 36571580 DOI: 10.1002/ana.26590] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 12/23/2022] [Accepted: 12/23/2022] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Myasthenia gravis (MG) is a neuromuscular disease mediated by antibodies against the acetylcholine receptor (AChR). The thymus plays a primary role in AChR-MG and is characterized by a type I interferon (IFN) signature linked to IFN-β. We investigated if AChR-MG was characterized by an IFN-I signature in the blood, and further investigated the chronic thymic IFN-I signature. METHODS Serum levels of IFN-β and IFN-α subtypes, and mRNA expression for IFN-I subtypes and IFN-stimulated genes in peripheral mononuclear blood cells (PBMCs) were analyzed. The contribution of endogenous nucleic acids in thymic expression of IFN-I subtypes was investigated in human thymic epithelial cell cultures and the mouse thymus. By immunohistochemistry, thymic CD68+ and CD163+ macrophages were analyzed in AChR-MG. To investigate the impact of a decrease in thymic macrophages, mice were treated with an anti-CSF1R antibody. RESULTS No IFN-I signature was observed in the periphery emphasizing that the IFN-I signature is restricted to the MG thymus. Molecules mimicking endogenous dsDNA signalization (Poly(dA:dT) and 2'3'-cGAMP), or dexamethasone-induced necrotic thymocytes increased IFN-β and α-AChR expression by thymic epithelial cells, and in the mouse thymus. A significant decrease in thymic macrophages was demonstrated in AChR-MG. In mice, a decrease in thymic macrophages led to an increase of necrotic thymocytes associated with IFN-β and α-AChR expression. INTERPRETATION These results suggest that the decrease of thymic macrophages in AChR-MG impairs the elimination of apoptotic thymocytes favoring the release of endogenous nucleic acids from necrotic thymocytes. In this inflammatory context, thymic epithelial cells may overexpress IFN-β, which specifically induces α-AChR, resulting in self-sensitization and thymic changes leading to AChR-MG. ANN NEUROL 2023.
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Affiliation(s)
- Cloé A Payet
- Sorbonne University, INSERM, Association Institute of Myology, Center of Research in Myology, UMRS, Paris, France
| | - Axel You
- Sorbonne University, INSERM, Association Institute of Myology, Center of Research in Myology, UMRS, Paris, France
| | - Odessa-Maud Fayet
- Sorbonne University, INSERM, Association Institute of Myology, Center of Research in Myology, UMRS, Paris, France
| | - Edouard Hemery
- Sorbonne University, INSERM, Association Institute of Myology, Center of Research in Myology, UMRS, Paris, France
| | - Frederique Truffault
- Sorbonne University, INSERM, Association Institute of Myology, Center of Research in Myology, UMRS, Paris, France
| | - Vincent Bondet
- Translational Immunology Unit, Institut Pasteur, Université Paris Cité, Paris, France
| | - Darragh Duffy
- Translational Immunology Unit, Institut Pasteur, Université Paris Cité, Paris, France
| | - Frédérique Michel
- Cytokine signaling unit, INSERM U1224, Institut Pasteur, Paris, France
| | - Elie Fadel
- Marie Lannelongue Hospital, Paris-Sud University, Le Plessis-Robinson, France
| | - Julien Guihaire
- Marie Lannelongue Hospital, Paris-Sud University, Le Plessis-Robinson, France
| | - Sophie Demeret
- Department of Neurology, Neuro Intensive Care Unit, Hôpital Pitié-Salpêtrière, APHP, Paris, France
| | - Sonia Berrih-Aknin
- Sorbonne University, INSERM, Association Institute of Myology, Center of Research in Myology, UMRS, Paris, France
| | - Rozen Le Panse
- Sorbonne University, INSERM, Association Institute of Myology, Center of Research in Myology, UMRS, Paris, France
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13
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Gong L, Tian J, Zhang Y, Feng Z, Wang Q, Wang Y, Zhang F, Zhang W, Huang G. Human Parvovirus B19 May Be a Risk Factor in Myasthenia Gravis with Thymoma. Ann Surg Oncol 2022; 30:1646-1655. [PMID: 36509875 PMCID: PMC9744379 DOI: 10.1245/s10434-022-12936-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 11/22/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE Our previous studies have demonstrated that human parvovirus B19 (B19V) is involved in the pathogenesis of thymic hyperplasia-associated myasthenia gravis (MG). However, more cases need to be assessed to further elucidate the relationship between this virus and thymoma-associated MG. MATERIALS AND METHODS The clinicopathological characteristics, presence of B19V DNA, and B19V VP2 capsid protein expression of 708 cases of thymomas were investigated using nested polymerase chain reaction (PCR), TaqMan quantitative (q) PCR, immunohistochemistry, fluorescent multiplex immunohistochemistry, and electron microscopy. RESULTS Patients with MG or ectopic germinal centers (GCs) were significantly younger than those without MG (P < 0.0001) or GCs (P = 0.0001). Moreover, significantly more GCs were detected in thymomas associated with MG than in those without MG (P < 0.0001). The results of nested PCR and TaqMan qPCR were consistent, and B19V DNA positivity was only associated with presence of GCs (P = 0.011). Immunohistochemically, positive staining was primarily detected in neoplastic thymic epithelial cells (TECs) and ectopic GCs. The positive rate of B19V VP2 was significantly higher in thymoma with MG or GCs than in thymoma without MG (P = 0.004) or GCs (P = 0.006). Electron microscopy showed B19V particles in the nuclei of neoplastic TECs and B cells from GCs. CONCLUSIONS We conclude that the pathogenesis of MG is closely associated with the presence of GCs, and B19V infection is plausibly an essential contributor to formation of ectopic GCs in thymoma. To the best of the authors' knowledge, this is the first study to elucidate the role of B19V in thymoma-associated MG and provide new ideas for exploring the etiopathogenic mechanism of MG.
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Affiliation(s)
- Li Gong
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi’an, People’s Republic of China
| | - Jing Tian
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi’an, People’s Republic of China
| | - Yan Zhang
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi’an, People’s Republic of China
| | - Zheng Feng
- Department of Thoracic Surgery, Tangdu Hospital, Air Force Medical University, Xi’an, People’s Republic of China
| | - Qiannan Wang
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi’an, People’s Republic of China
| | - Yan Wang
- Department of Stomatology, Tangdu Hospital, Air Force Medical University, Xi’an, People’s Republic of China
| | - Fuqin Zhang
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi’an, People’s Republic of China
| | - Wei Zhang
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi'an, People's Republic of China.
| | - Gaosheng Huang
- Department of Pathology, Helmholtz Sina-German Research Laboratory for Cancer, Tangdu Hospital, Air Force Medical University, Xi'an, People's Republic of China. .,State Key Laboratory of Cancer Biology, Department of Pathology, Xijing Hospital, Air Force Medical University, Xi'an, People's Republic of China.
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14
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Keller CW, Chuquisana O, Derdelinckx J, Gross CC, Berger K, Robinson J, Nimmerjahn F, Wiendl H, Willcox N, Lünemann JD. Impaired B cell Expression of the Inhibitory Fcγ Receptor IIB in Myasthenia Gravis. Ann Neurol 2022; 92:1046-1051. [PMID: 36094152 DOI: 10.1002/ana.26507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/08/2022]
Abstract
Myasthenia gravis (MG) is an autoimmune disease in which pathogenic immunoglobulin G (IgG) antibodies (Abs) bind to acetylcholine receptors (AChR) or to functionally related molecules at the neuromuscular junction. B cell expression of the inhibitory IgG receptor, FcγRIIB, maintains peripheral immune tolerance and its absence renders B cells hyperresponsive to autoantigen. Here, we report that FcγRIIB expression levels are substantially reduced in B lineage cells derived from immunotherapy-naïve patients with AChR-Ab+ early-onset MG (EOMG). In contrast, genetic variants associated with impaired FcγRIIB expression are not enriched in MG, indicating post-transcriptional dysregulation. FcγR-targeted therapies could have therapeutic benefits in MG. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Christian W Keller
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Omar Chuquisana
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Judith Derdelinckx
- Department of Neurology, Faculty of Medicine and Health Sciences, Antwerp University Hospital, Antwerp, Belgium.,Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (VaxInfectio), Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Catharina C Gross
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Klaus Berger
- Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
| | - James Robinson
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT Laboratories, Leeds, UK.,National Institute of Health Research-Leeds Biomedical Research Centre, Chapel Allerton Hospital, Leeds, LS7 4SA, UK
| | - Falk Nimmerjahn
- Chair of Genetics, Department of Biology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany.,Medical Immunology Campus Erlangen, Erlangen, Germany
| | - Heinz Wiendl
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Nick Willcox
- Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Jan D Lünemann
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
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15
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Chen K, Li Y, Yang H. Poor responses and adverse outcomes of myasthenia gravis after thymectomy: Predicting factors and immunological implications. J Autoimmun 2022; 132:102895. [PMID: 36041292 DOI: 10.1016/j.jaut.2022.102895] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 08/09/2022] [Accepted: 08/11/2022] [Indexed: 10/15/2022]
Abstract
Myasthenia gravis (MG) has been recognized as a series of heterogeneous but treatable autoimmune conditions. As one of the indispensable therapies, thymectomy can achieve favorable prognosis especially in early-onset generalized MG patients with seropositive acetylcholine receptor antibody. However, poor outcomes, including worsening or relapse of MG, postoperative myasthenic crisis and even post-thymectomy MG, are also observed in certain scenarios. The responses to thymectomy may be associated with the general characteristics of patients, disease conditions of MG, autoantibody profiles, native or ectopic thymic pathologies, surgical-related factors, pharmacotherapy and other adjuvant modalities, and the presence of comorbidities and complications. However, in addition to these variations among individuals, pathological remnants and the abnormal immunological milieu and responses potentially represent major mechanisms that underlie the detrimental neurological outcomes after thymectomy. We underscore these plausible risk factors and discuss the immunological implications therein, which may be conducive to better managing the indications for thymectomy, to avoiding modifiable risk factors of poor responses and adverse outcomes, and to developing post-thymectomy preventive and therapeutic strategies for MG.
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Affiliation(s)
- Kangzhi Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yi Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.
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16
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Yoshioka N, Naito Y, Sano K, Sano C, Ohta R. Seronegative Ocular Myasthenia Gravis in an Older Woman With Transient Dizziness and Diplopia. Cureus 2022; 14:e27826. [PMID: 36106280 PMCID: PMC9456555 DOI: 10.7759/cureus.27826] [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] [Accepted: 08/09/2022] [Indexed: 11/25/2022] Open
Abstract
Myasthenia gravis (MG) is a neuromuscular junction disease caused by an autoimmune response against cholinergic receptors. The challenge in diagnosing MG in older patients is the variety of symptoms and clinical manifestations. Clinical reasoning, precise history, and physical examination leading to a logical diagnosis should be performed to diagnose seronegative MG. We report a case of seronegative MG with the chief complaint of dizziness in a 91-year-old female. Despite the complicated clinical course, continuous clinical reasoning and testing can lead to appropriate diagnosis and treatment. As the dizziness symptoms in this older patient could not be explained by chronic or peripheral symptoms alone, ocular MG was considered as a possible diagnosis based on her history and physical examination findings. Appropriate diagnosis of seronegative ocular MG reactivated older patients with a good quality of life. In community medicine, where the behavior of elderly patients varies, it is important to improve the accuracy of diagnosis and treatment through appropriate history and physical examination, which will lead to longer home life in older patients.
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17
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Thapa L, Thapa M, Bhattarai S, Shrestha AM, Sharma N, Rai N, Pokharel M, Paudel R. D-penicillamine Induced Myasthenia Gravis in Wilson's Disease: A Case Report. JNMA J Nepal Med Assoc 2022; 60:644-647. [PMID: 36705187 PMCID: PMC9297353 DOI: 10.31729/jnma.7607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 06/25/2022] [Indexed: 01/31/2023] Open
Abstract
Myasthenia gravis is a neuromuscular junction disorder characterised by fluctuating muscle weakness, improved by using anti-cholinesterase drugs. In addition to the autoimmune aetiology, various factors such as infections, surgery, and drugs are known to precipitate the condition. We report a case of a 15-year-old boy with D-penicillamine-induced myasthenia gravis who presented with facial diplegia, dysphagia, and drooling of saliva, 6 years after the initiation of treatment for Wilson's disease. Therefore, clinicians should be more vigilant while prescribing patients with chelating drugs like D-penicillamine with regular monitoring of the new symptoms and keeping a very low threshold for the suspicion of myasthenia gravis. Keywords d-penicillamine; myasthenia gravis; pyridostigmine; Wilson's disease.
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Affiliation(s)
- Lekhjung Thapa
- Department of Neurology, National Neuro Center, Maharajgunj, Chakrapath, Kathmandu, Nepal,Correspondence: Dr Lekhjung Thapa, Department of Neurology, National Neuro Centre, Maharajgunj, Kathmandu, Nepal. , Phone: +977-9749370390
| | - Monika Thapa
- Department of Neurology, National Neuro Center, Maharajgunj, Chakrapath, Kathmandu, Nepal
| | - Suman Bhattarai
- Department of Neurology, National Neuro Center, Maharajgunj, Chakrapath, Kathmandu, Nepal
| | - Abhishek Man Shrestha
- Department of Neurology, National Neuro Center, Maharajgunj, Chakrapath, Kathmandu, Nepal
| | - Nooma Sharma
- Department of Neurology, National Neuro Center, Maharajgunj, Chakrapath, Kathmandu, Nepal
| | - Nilshan Rai
- KIST Medical College and Teaching Hospital, Imadol, Lalitpur, Nepal
| | - Merina Pokharel
- Department of Neurology, National Neuro Center, Maharajgunj, Chakrapath, Kathmandu, Nepal
| | - Raju Paudel
- Department of Neurology, National Neuro Center, Maharajgunj, Chakrapath, Kathmandu, Nepal
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18
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Zhou Y, Chen J, Li Z, Tan S, Yan C, Luo S, Zhou L, Song J, Huan X, Wang Y, Zhao C, Zeng W, Xi J. Clinical Features of Myasthenia Gravis With Antibodies to MuSK Based on Age at Onset: A Multicenter Retrospective Study in China. Front Neurol 2022; 13:879261. [PMID: 35463138 PMCID: PMC9033288 DOI: 10.3389/fneur.2022.879261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 03/18/2022] [Indexed: 11/14/2022] Open
Abstract
Introduction Antibodies to MuSK identify a rare subtype of myasthenia gravis (MuSK-MG). In western countries, the onset age of MuSK-MG peaks in the late 30's while it is unknown in Chinese population. Methods In this retrospective multicenter study, we screened 69 MuSK-MG patients from 2042 MG patients in five tertiary referral centers in China from October 2016 to October 2021 and summarized the clinical features and treatment outcomes. Then we subgrouped the patients into early-onset (<50 years old), late-onset (50–64 years old), and very-late-onset (≥65 years old) MG and compared the differences in weakness distribution, disease progression and treatment outcomes among three subgroups. Results The patients with MuSK-MG were female-dominant (55/69) and their mean age at onset was 44.70 ± 15.84 years old, with a broad range of 17–81 years old. At disease onset, 29/69 patients were classified as MGFA Type IIb and the frequency of bulbar and extraocular involvement was 53.6 and 69.6%, respectively. There was no difference in weakness distribution. Compared with early-onset MuSK-MG, very-late-onset patients had a higher proportion of limb muscle involvement (12/15 vs.16/40, p = 0.022) 3 months after onset. Six months after onset, more patients with bulbar (14/15 vs. 26/39, p = 0.044) and respiratory involvement (6/15 vs. 0/13, p = 0.013) were seen in very-late-onset than in late-onset subgroup. The very-late-onset subgroup had the highest frequency of limb weakness (86.7%, p < 0.001). One year after onset, very-late-onset patients demonstrated a higher frequency of respiratory involvement than early-onset patients (4/12 vs. 2/35, p = 0.036). 39/64 patients reached MSE. Among 46 patients who received rituximab, very-late-onset patients started earlier than late-onset patients [6 (5.5–7.5) vs. 18 (12–65) months, p = 0.039], but no difference in the time and rate to achieving MSE was identified. Conclusion MuSK-MG patients usually manifested as acute onset and predominant bulbar and respiratory involvement with female dominance. Very-late-onset patients displayed an early involvement of limb, bulbar and respiratory muscles in the disease course, which might prompt their earlier use of rituximab. The majority MuSK-MG patients can benefit from rituximab treatment regardless of age at onset.
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Affiliation(s)
- Yufan Zhou
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Diseases, Shanghai, China
| | - Jialin Chen
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Zunbo Li
- Department of Neurology, Xi'an Gaoxin Hospital, Xi'an, China
| | - Song Tan
- Department of Neurology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Chong Yan
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Diseases, Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Diseases, Shanghai, China
| | - Lei Zhou
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Diseases, Shanghai, China
| | - Jie Song
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Diseases, Shanghai, China
| | - Xiao Huan
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Diseases, Shanghai, China
| | - Ying Wang
- Department of Pharmacy, Huashan Hospital, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Diseases, Shanghai, China
| | - Wenshuang Zeng
- Department of Neurology, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China
- Wenshuang Zeng
| | - Jianying Xi
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
- Huashan Rare Disease Center, Huashan Hospital, Fudan University, Shanghai, China
- National Center for Neurological Diseases, Shanghai, China
- *Correspondence: Jianying Xi
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19
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Payet CA, You A, Fayet OM, Dragin N, Berrih-Aknin S, Le Panse R. Myasthenia Gravis: An Acquired Interferonopathy? Cells 2022; 11:cells11071218. [PMID: 35406782 PMCID: PMC8997999 DOI: 10.3390/cells11071218] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/23/2022] [Accepted: 03/28/2022] [Indexed: 01/12/2023] Open
Abstract
Myasthenia gravis (MG) is a rare autoimmune disease mediated by antibodies against components of the neuromuscular junction, particularly the acetylcholine receptor (AChR). The thymus plays a primary role in AChR-MG patients. In early-onset AChR-MG and thymoma-associated MG, an interferon type I (IFN-I) signature is clearly detected in the thymus. The origin of this chronic IFN-I expression in the thymus is not yet defined. IFN-I subtypes are normally produced in response to viral infection. However, genetic diseases called interferonopathies are associated with an aberrant chronic production of IFN-I defined as sterile inflammation. Some systemic autoimmune diseases also share common features with interferonopathies. This review aims to analyze the pathogenic role of IFN-I in these diseases as compared to AChR-MG in order to determine if AChR-MG could be an acquired interferonopathy.
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Affiliation(s)
- Cloé A Payet
- Sorbonne University, INSERM, Institute of Myology, Center of Research in Myology, F-75013 Paris, France
| | - Axel You
- Sorbonne University, INSERM, Institute of Myology, Center of Research in Myology, F-75013 Paris, France
| | - Odessa-Maud Fayet
- Sorbonne University, INSERM, Institute of Myology, Center of Research in Myology, F-75013 Paris, France
| | - Nadine Dragin
- Sorbonne University, INSERM, Institute of Myology, Center of Research in Myology, F-75013 Paris, France
| | - Sonia Berrih-Aknin
- Sorbonne University, INSERM, Institute of Myology, Center of Research in Myology, F-75013 Paris, France
| | - Rozen Le Panse
- Sorbonne University, INSERM, Institute of Myology, Center of Research in Myology, F-75013 Paris, France
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20
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Bortone F, Scandiffio L, Cavalcante P, Mantegazza R, Bernasconi P. Epstein-Barr Virus in Myasthenia Gravis: Key Contributing Factor Linking Innate Immunity with B-Cell-Mediated Autoimmunity. Infect Dis (Lond) 2021. [DOI: 10.5772/intechopen.93777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Epstein-Barr virus (EBV), a common human herpes virus latently infecting most of the world’s population with periodic reactivations, is the main environmental factor suspected to trigger and/or sustain autoimmunity by its ability to disrupt B-cell tolerance checkpoints. Myasthenia gravis (MG) is a prototypic autoimmune disorder, mostly caused by autoantibodies to acetylcholine receptor (AChR) of the neuromuscular junction, which cause muscle weakness and fatigability. Most patients display hyperplastic thymus, characterized by ectopic germinal center formation, chronic inflammation, exacerbated Toll-like receptor activation, and abnormal B-cell activation. After an overview on MG clinical features and intra-thymic pathogenesis, in the present chapter, we describe our main findings on EBV presence in MG thymuses, including hyperplastic and thymoma thymuses, in relationship with innate immunity activation and data from other autoimmune conditions. Our overall data strongly indicate a critical contribution of EBV to innate immune dysregulation and sustained B-cell-mediated autoimmune response in the pathological thymus of MG patients.
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21
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Greaves RB, Chen D, Green EA. Thymic B Cells as a New Player in the Type 1 Diabetes Response. Front Immunol 2021; 12:772017. [PMID: 34745148 PMCID: PMC8566354 DOI: 10.3389/fimmu.2021.772017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/01/2021] [Indexed: 12/27/2022] Open
Abstract
Type 1 diabetes (T1d) results from a sustained autoreactive T and B cell response towards insulin-producing β cells in the islets of Langerhans. The autoreactive nature of the condition has led to many investigations addressing the genetic or cellular changes in primary lymphoid tissues that impairs central tolerance- a key process in the deletion of autoreactive T and B cells during their development. For T cells, these studies have largely focused on medullary thymic epithelial cells (mTECs) critical for the effective negative selection of autoreactive T cells in the thymus. Recently, a new cellular player that impacts positively or negatively on the deletion of autoreactive T cells during their development has come to light, thymic B cells. Normally a small population within the thymus of mouse and man, thymic B cells expand in T1d as well as other autoimmune conditions, reside in thymic ectopic germinal centres and secrete autoantibodies that bind selective mTECs precipitating mTEC death. In this review we will discuss the ontogeny, characteristics and functionality of thymic B cells in healthy and autoimmune settings. Furthermore, we explore how in silico approaches may help decipher the complex cellular interplay of thymic B cells with other cells within the thymic microenvironment leading to new avenues for therapeutic intervention.
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Affiliation(s)
- Richard B Greaves
- Centre for Experimental Medicine and Biomedicine, Hull York Medical School, University of York, York, United Kingdom
| | - Dawei Chen
- Centre for Experimental Medicine and Biomedicine, Hull York Medical School, University of York, York, United Kingdom
| | - E Allison Green
- Centre for Experimental Medicine and Biomedicine, Hull York Medical School, University of York, York, United Kingdom
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22
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Zhao R, Luo S, Zhao C. The role of innate immunity in myasthenia gravis. Autoimmun Rev 2021; 20:102800. [PMID: 33722749 DOI: 10.1016/j.autrev.2021.102800] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 12/19/2022]
Abstract
Myasthenia gravis (MG) is a T cell-driven, B cell-mediated and autoantibody-dependent autoimmune disorder against neuromuscular junctions (NMJ). Accumulated evidence has emerged regarding the role of innate immunity in the pathogenesis of MG. In this review, we proposed two hypothesis underlying the pathological mechanism. In the context of gene predisposition, on the one hand, Toll-like receptors (TLRs) pathways were initiated by viral infection in the thymus with MG to generate chemokines and pro-inflammatory cytokines such as Type I interferon (IFN), which facilitate the thymus to function as a tertiary lymphoid organ (TLO). On the another hand, the antibodies against acetylcholine receptors (AChR) generated by thymus then activated the classical pathways on thymus and neuromuscular junction (NMJ). Futher, we also highlight the role of innate immune cells in the pathogenic response. Finally, we provide some future perspectives in developing new therapeutic approaches particularly targeting the innate immunity for MG.
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Affiliation(s)
- Rui Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China.
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Marx A, Yamada Y, Simon-Keller K, Schalke B, Willcox N, Ströbel P, Weis CA. Thymus and autoimmunity. Semin Immunopathol 2021; 43:45-64. [PMID: 33537838 PMCID: PMC7925479 DOI: 10.1007/s00281-021-00842-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/12/2021] [Indexed: 12/19/2022]
Abstract
The thymus prevents autoimmune diseases through mechanisms that operate in the cortex and medulla, comprising positive and negative selection and the generation of regulatory T-cells (Tregs). Egress from the thymus through the perivascular space (PVS) to the blood is another possible checkpoint, as shown by some autoimmune/immunodeficiency syndromes. In polygenic autoimmune diseases, subtle thymic dysfunctions may compound genetic, hormonal and environmental cues. Here, we cover (a) tolerance-inducing cell types, whether thymic epithelial or tuft cells, or dendritic, B- or thymic myoid cells; (b) tolerance-inducing mechanisms and their failure in relation to thymic anatomic compartments, and with special emphasis on human monogenic and polygenic autoimmune diseases and the related thymic pathologies, if known; (c) polymorphisms and mutations of tolerance-related genes with an impact on positive selection (e.g. the gene encoding the thymoproteasome-specific subunit, PSMB11), promiscuous gene expression (e.g. AIRE, PRKDC, FEZF2, CHD4), Treg development (e.g. SATB1, FOXP3), T-cell migration (e.g. TAGAP) and egress from the thymus (e.g. MTS1, CORO1A); (d) myasthenia gravis as the prototypic outcome of an inflamed or disordered neoplastic ‘sick thymus’.
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Affiliation(s)
- Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
| | - Yosuke Yamada
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
- Department of Diagnostic Pathology, Kyoto University Hospital, Kyoto, 606-8507, Japan
| | - Katja Simon-Keller
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Berthold Schalke
- Department of Neurology, Bezirkskrankenhaus, University of Regensburg, 93042, Regensburg, Germany
| | - Nick Willcox
- Neurosciences Group, Nuffield Department of Clinical Neurology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Philipp Ströbel
- Institute of Pathology, University Medical Center Göttingen, University of Göttigen, 37075, Göttingen, Germany
| | - Cleo-Aron Weis
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
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Farrugia ME, Goodfellow JA. A Practical Approach to Managing Patients With Myasthenia Gravis-Opinions and a Review of the Literature. Front Neurol 2020; 11:604. [PMID: 32733360 PMCID: PMC7358547 DOI: 10.3389/fneur.2020.00604] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/25/2020] [Indexed: 12/14/2022] Open
Abstract
When the diagnosis of myasthenia gravis (MG) has been secured, the aim of management should be prompt symptom control and the induction of remission or minimal manifestations. Symptom control, with acetylcholinesterase inhibitors such as pyridostigmine, is commonly employed. This may be sufficient in mild disease. There is no single universally accepted treatment regimen. Corticosteroids are the mainstay of immunosuppressive treatment in patients with more than mild MG to induce remission. Immunosuppressive therapies, such as azathioprine are prescribed in addition to but sometimes instead of corticosteroids when background comorbidities preclude or restrict the use of steroids. Rituximab has a role in refractory MG, while plasmapheresis and immunoglobulin therapy are commonly prescribed to treat MG crisis and in some cases of refractory MG. Data from the MGTX trial showed clear evidence that thymectomy is beneficial in patients with acetylcholine receptor (AChR) antibody positive generalized MG, up to the age of 65 years. Minimally invasive thymectomy surgery including robotic-assisted thymectomy surgery has further revolutionized thymectomy and the management of MG. Ocular MG is not life-threatening but can be significantly disabling when diplopia is persistent. There is evidence to support early treatment with corticosteroids when ocular motility is abnormal and fails to respond to symptomatic treatment. Treatment needs to be individualized in the older age-group depending on specific comorbidities. In the younger age-groups, particularly in women, consideration must be given to the potential teratogenicity of certain therapies. Novel therapies are being developed and trialed, including ones that inhibit complement-induced immunological pathways or interfere with antibody-recycling pathways. Fatigue is common in MG and should be duly identified from fatigable weakness and managed with a combination of physical therapy with or without psychological support. MG patients may also develop dysfunctional breathing and the necessary respiratory physiotherapy techniques need to be implemented to alleviate the patient's symptoms of dyspnoea. In this review, we discuss various facets of myasthenia management in adults with ocular and generalized disease, including some practical approaches and our personal opinions based on our experience.
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Affiliation(s)
- Maria Elena Farrugia
- Neurology Department, Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, United Kingdom
| | - John A Goodfellow
- Neurology Department, Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, United Kingdom.,Neuroimmunology Laboratory, Laboratory Medicine and Facilities Building, Queen Elizabeth University Hospital, Glasgow, United Kingdom
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Çebi M, Durmus H, Aysal F, Özkan B, Gül GE, Çakar A, Hocaoglu M, Mercan M, Yentür SP, Tütüncü M, Yayla V, Akan O, Dogan Ö, Parman Y, Saruhan-Direskeneli G. CD4 + T Cells of Myasthenia Gravis Patients Are Characterized by Increased IL-21, IL-4, and IL-17A Productions and Higher Presence of PD-1 and ICOS. Front Immunol 2020; 11:809. [PMID: 32508812 PMCID: PMC7248174 DOI: 10.3389/fimmu.2020.00809] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/08/2020] [Indexed: 12/19/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease mediated by autoantibodies predominantly against the acetylcholine receptor (AChR). Specific T cell subsets are required for long-term antibody responses, and cytokines secreted mainly from CD4+ T cells regulate B cell antibody production. The aim of this study was to assess the differences in the cytokine expressions of CD4+ T cells in MG patients with AChR antibodies (AChR-MG) and the effect of immunosuppressive (IS) therapy on cytokine activity and to test these findings also in MG patients without detectable antibodies (SN-MG). Clinically diagnosed AChR-MG and SN-MG patients were included. The AChR-MG patients were grouped as IS-positive and -negative and compared with age- and sex-matched healthy controls. Peripheral blood mononuclear cells were used for ex vivo intracellular cytokine production, and subsets of CD4+ T cells and circulating follicular helper T (cTfh) cells were detected phenotypically by the expression of the chemokine and the costimulatory receptors. Thymocytes obtained from patients who had thymectomy were also analyzed. IL-21, IL-4, IL-10, and IL-17A productions in CD4+ T cells were increased in AChR-MG compared to those in healthy controls. IS treatment enhanced IL-10 and reduced IFN-γ production in AChR-MG patients compared to those in IS-negative patients. Increased IL-21 and IL-4 productions were also demonstrated in SN-MG patients. Among CD4+ T cells, Th17 cells were increased in both disease subgroups. Treatment induced higher proportions of Th2 cells in AChR-MG patients. Both CXCR5+ and CXCR5− CD4+ T cells expressed higher programmed cell death protein 1 (PD-1) and inducible costimulatory (ICOS) in AChR-MG and SN-MG groups, mostly irrespective of the treatment. Based on chemokine receptors on CXCR5+PD-1+ in CD4+ T (cTfh) cells, in AChR-MG patients without treatment, the proportions of Tfh17 cells were higher than those in the treated group, whereas the Tfh1 cells were decreased compared with those in the controls. The relevance of CXCR5 and PD-1 in the pathogenesis of AChR-MG was also suggested by the increased presence of these molecules on mature CD4 single-positive thymocytes from the thymic samples. The study provides further evidence for the importance of IL-21, IL-17A, IL-4, and IL-10 in AChR-MG. Disease-related CD4+T cells are identified mainly as PD-1+ or ICOS+ with or without CXCR5, resembling cTfh cells in the circulation or probably in the thymus. AChR-MG and SN-MG seem to have some similar characteristics. IS treatment has distinctive effects on cytokine expression.
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Affiliation(s)
- Merve Çebi
- Department of Physiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Hacer Durmus
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Fikret Aysal
- Department of Neurology, Medipol University, Istanbul, Turkey
| | - Berker Özkan
- Department of Thoracic Surgery, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | | | - Arman Çakar
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Mehmet Hocaoglu
- Department of Physiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Metin Mercan
- Bakirköy Sadi Konuk State Hospital, Istanbul, Turkey
| | - Sibel P Yentür
- Department of Physiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Melih Tütüncü
- Department of Neurology, Cerrahpaşa Medical Faculty, Istanbul University Cerrahpaşa, Istanbul, Turkey
| | - Vildan Yayla
- Bakirköy Sadi Konuk State Hospital, Istanbul, Turkey
| | - Onur Akan
- Okmeydani State Hospital, Istanbul, Turkey
| | - Öner Dogan
- Department of Pathology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Yeşim Parman
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
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26
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Angelopoulou E, Paudel YN, Piperi C. Unraveling the Role of Receptor for Advanced Glycation End Products (RAGE) and Its Ligands in Myasthenia Gravis. ACS Chem Neurosci 2020; 11:663-673. [PMID: 32017530 DOI: 10.1021/acschemneuro.9b00678] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune T cell-dependent B cell-mediated disorder of the neuromuscular junction (NMJ) characterized by fluctuating skeletal muscle weakness, most commonly attributed to pathogenic autoantibodies against postsynaptic nicotinic acetylcholine receptors (AChRs). Although MG pathogenesis is well-documented, there are no objective biomarkers that could effectively correlate with disease severity or MG clinical subtypes, and current treatment approaches are often ineffective. The receptor for advanced glycation end products (RAGE) is a multiligand cell-bound receptor highly implicated in proinflammatory responses and autoimmunity. Preclinical evidence demonstrates that RAGE and its ligand S100B are upregulated in rat models of experimental autoimmune myasthenia gravis (EAMG). S100B-mediated RAGE activation has been shown to exacerbate EAMG, by enhancing T cell proinflammatory responses, aggravating T helper (Th) subset imbalance, increasing AChR-specific T cell proliferative capacity, and promoting the production of antibodies against AChRs from the spleen. Soluble sRAGE and esRAGE, acting as decoys of RAGE ligands, are found to be significantly reduced in MG patients. Moreover, MG has been associated with increased serum levels of S100A12, S100B and HMGB1. Several studies have shown that the presence of thymic abnormalities, the onset age of MG, and the duration of the disease may affect the levels of these proteins in MG patients. Herein, we discuss the emerging role of RAGE and its ligands in MG immunopathogenesis, their clinical significance as promising biomarkers, as well as the potential therapeutic implications of targeting RAGE signaling in MG treatment.
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Affiliation(s)
- Efthalia Angelopoulou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Yam Nath Paudel
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, 46150 Selangor, Malaysia
| | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
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Myasthenia Gravis: Pathogenic Effects of Autoantibodies on Neuromuscular Architecture. Cells 2019; 8:cells8070671. [PMID: 31269763 PMCID: PMC6678492 DOI: 10.3390/cells8070671] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 06/26/2019] [Accepted: 06/28/2019] [Indexed: 12/13/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction (NMJ). Autoantibodies target key molecules at the NMJ, such as the nicotinic acetylcholine receptor (AChR), muscle-specific kinase (MuSK), and low-density lipoprotein receptor-related protein 4 (Lrp4), that lead by a range of different pathogenic mechanisms to altered tissue architecture and reduced densities or functionality of AChRs, reduced neuromuscular transmission, and therefore a severe fatigable skeletal muscle weakness. In this review, we give an overview of the history and clinical aspects of MG, with a focus on the structure and function of myasthenic autoantigens at the NMJ and how they are affected by the autoantibodies' pathogenic mechanisms. Furthermore, we give a short overview of the cells that are implicated in the production of the autoantibodies and briefly discuss diagnostic challenges and treatment strategies.
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Paz ML, Barrantes FJ. Autoimmune Attack of the Neuromuscular Junction in Myasthenia Gravis: Nicotinic Acetylcholine Receptors and Other Targets. ACS Chem Neurosci 2019; 10:2186-2194. [PMID: 30916550 DOI: 10.1021/acschemneuro.9b00041] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The nicotinic acetylcholine receptor (nAChR) family, the archetype member of the pentameric ligand-gated ion channels, is ubiquitously distributed in the central and peripheral nervous systems, and its members are the targets for both genetic and acquired forms of neurological disorders. In the central nervous system, nAChRs contribute to the pathological mechanisms of neurodegenerative disorders, such as Alzheimer and Parkinson diseases. In the peripheral nerve-muscle synapse, the vertebrate neuromuscular junction, "classical" myasthenia gravis (MG) and other forms of neuromuscular transmission disorders are antibody-mediated autoimmune diseases. In MG, antibodies to the nAChR bind to the postsynaptic receptors and activate the classical complement pathway culminating in the formation of the membrane attack complex, with the subsequent destruction of the postsynaptic apparatus. Divalent nAChR-antibodies also cause internalization and loss of the nAChRs. Loss of receptors by either mechanism results in the muscle weakness and fatigability that typify the clinical manifestations of the disease. Other targets for antibodies, in a minority of patients, include muscle specific kinase (MuSK) and low-density lipoprotein related protein 4 (LRP4). This brief Review analyzes the current status of muscle-type nAChR in relation to the pathogenesis of autoimmune diseases affecting the peripheral cholinergic synapse.
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Affiliation(s)
- Mariela L. Paz
- Immunology Department, Faculty of Pharmacy and Biochemistry, IDEHU-CONICET, University of Buenos Aires, Junin 956, C1113AAD Buenos Aires, Argentina
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Biomedical Research Institute (BIOMED), UCA-CONICET, Av. Alicia Moreau de Justo 1600, C1107AFF Buenos Aires, Argentina
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29
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The enigmatic thymic myoid cells – their 130 years of history, embryonic origin, function and clinical significance. Biologia (Bratisl) 2019. [DOI: 10.2478/s11756-019-00214-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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30
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Cao YL, Dong W, Li YZ, Han W. MicroRNA-653 Inhibits Thymocyte Proliferation and Induces Thymocyte Apoptosis in Mice with Autoimmune Myasthenia Gravis by Downregulating TRIM9. Neuroimmunomodulation 2019; 26:7-18. [PMID: 30703767 DOI: 10.1159/000494802] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/23/2018] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Myasthenia gravis (MG) is an organ-specific autoimmune neuromuscular disorder that occurs as a result of the impairment in neuromuscular junction and autoantibody attack on the postsynaptic receptors. Increasing evidence suggests that microRNAs (miRs) might be involved in the development of MG. Therefore, the present study aimed to investigate the regulatory function of miR-653 on MG and its relationship with tripartite motif 9 (TRIM9). METHODS The thymic tissues obtained from MG patients with thymic hyperplasia were prepared for establishing an MG mouse model in BALB/c mice. Afterwards, the miR-653 and TRIM9 expressions were determined in thymic tissues. A dual-luciferase reporter assay was carried out to validate whether miR-653 directly targets TRIM9. Finally, the thymocytes were exposed to mimics or inhibitors of miR-653, or siRNA against TRIM9 with the use of MTT assays and flow cytometry for the verification of the gain or loss function of miR-653 and TRIM9 on viability, cell cycle progression, and apoptosis of thymocytes. RESULTS There was a decrease in thymocyte miR-653 and an increase in TRIM9 in thymic tissues of MG mice. miR-653 was found to negatively regulate TRIM9. Overexpression of miR-653 or depletion of TRIM9 resulted in the inhibition of cell viability, suppression of cell cycle progression, and induction of apoptosis rate in thymocytes. CONCLUSION The findings from the present study provided evidence that miR-653 impairs proliferation and promotes apoptosis of thymocytes of MG mice by suppressing TRIM9, indicating that miR-653 could be used as potential therapeutic target in the treatment of autoimmune MG.
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Affiliation(s)
- Yu-Ling Cao
- Department of Neurology, Jining No. 1 People's Hospital, Jining, China
| | - Wei Dong
- Department of Emergency, Jining No. 1 People's Hospital, Jining, China,
| | - Yu-Zhi Li
- Department of Neurology, Jining No. 1 People's Hospital, Jining, China
| | - Wei Han
- Department of Neurology, Jining No. 1 People's Hospital, Jining, China
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31
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Koneczny I, Rennspiess D, Marcuse F, Dankerlui N, Abdul Hamid M, Mané-Damas M, Maessen J, Van Schil P, Saxena A, Zisimopoulou P, Lazaridis K, Woodhall M, Karagiorgou K, Tzartos J, Tzartos S, De Baets MH, Molenaar PC, Marx A, Zur Hausen A, Losen M, Martinez-Martinez P. Characterization of the thymus in Lrp4 myasthenia gravis: Four cases. Autoimmun Rev 2018; 18:50-55. [PMID: 30414949 DOI: 10.1016/j.autrev.2018.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 07/24/2018] [Indexed: 12/20/2022]
Abstract
Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction. Most patients have pathogenic autoantibodies against the acetylcholine receptor (AChR). In the last years a novel subpopulation of MG patients has been described that harbors antibodies against low-density lipoprotein receptor-related protein 4 (Lrp4), another postsynaptic neuromuscular antigen. In early-onset AChR MG (EOMG), the thymus plays an important role in immunopathogenesis, and early thymectomy is beneficial. It is still unknown if the thymus plays any role in Lrp4-MG. In this pilot study, we compared thymus samples from four patients with Lrp4-MG (one pre-treated with immunosuppressive drugs), four non-MG controls and five EOMG patients (not pretreated with immunosuppressive drugs). Immunohistochemistry of the Lrp4-MG thymi revealed normal architecture, with normal numbers and distribution of B-cells, lymphoid follicles and Hassall's corpuscles. Primary CD23+ lymphoid follicles were similarly infrequent in Lrp4-MG and control thymic sections. In none of the control or Lrp4-MG thymi did we find secondary follicles with CD10+ germinal centers. These were evident in 2 of the 5 EOMG thymi, where primary lymphoid follicles were also more frequent on average, thus showing considerable heterogeneity between patients. Even if characteristic pathological thymic changes were not observed in the Lrp4 subgroup, we cannot exclude a role for the thymus in Lrp4-MG pathogenesis, since one Lrp4-MG patient went into clinical remission after thymectomy alone (at one year follow-up) and one more improved after thymectomy in combination with immunosuppressive therapy.
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Affiliation(s)
- Inga Koneczny
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, the Netherlands
| | - Dorit Rennspiess
- Department of Pathology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Florit Marcuse
- Department of Pathology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Nathalie Dankerlui
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, the Netherlands
| | - Myurgia Abdul Hamid
- Department of Pathology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Marina Mané-Damas
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, the Netherlands
| | - Jos Maessen
- Department of Pathology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Paul Van Schil
- Dept. of Thoracic and Vascular Surgery, University Hospital of Antwerp, Wilrijkstraat 10, Edegem (Antwerp), B- 2650, Belgium
| | - Abhishek Saxena
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, the Netherlands
| | - Paraskevi Zisimopoulou
- Department of Neurobiology, Hellenic Pasteur Institute, 127 Vas. Sofias Avenue, 11521 Athens, Greece
| | - Konstantinos Lazaridis
- Department of Neurobiology, Hellenic Pasteur Institute, 127 Vas. Sofias Avenue, 11521 Athens, Greece
| | - Mark Woodhall
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Level 6, West Wing, University of Oxford, Oxford OX3 9DU, UK
| | | | - John Tzartos
- Department of Neurobiology, Hellenic Pasteur Institute, 127 Vas. Sofias Avenue, 11521 Athens, Greece; Tzartos Neuro Diagnostics, 3 Eslin Street, 11523 Athens, Greece
| | - Socrates Tzartos
- Department of Neurobiology, Hellenic Pasteur Institute, 127 Vas. Sofias Avenue, 11521 Athens, Greece
| | - Marc H De Baets
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, the Netherlands
| | - Peter C Molenaar
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, the Netherlands
| | - Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim, Germany
| | - Axel Zur Hausen
- Department of Pathology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands; GROW: School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, the Netherlands
| | - Mario Losen
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, the Netherlands.
| | - Pilar Martinez-Martinez
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, the Netherlands.
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Abstract
Acquired Myasthenia Gravis (MG) is a neuromuscular disease caused by autoantibodies against components of the neuromuscular junction. It is a prototype organ-specific autoimmune disease with well-defined antigenic targets mainly the nicotinic acetylcholine receptor (AChR). Patients suffer from fluctuating, fatigable muscle weakness that worsens with activity and improves with rest. Various therapeutic strategies have been used over the years to alleviate MG symptoms. These strategies aim at improving the transmission of the nerve impulse to muscle or at lowering the immune system with steroids or immunosuppressant drugs. Nevertheless, MG remains a chronic disease and symptoms tend to persist in many patients, some being or becoming refractory over time. In this review, based on recent experimental data on MG or based on results from clinical trials for other autoimmune diseases, we explore new potential therapeutic approaches for MG patients, going from non-specific approaches with the use of stem cells with their anti-inflammatory and immunosuppressive properties to targeted therapies using monoclonal antibodies specific for cell-surface antigens or circulating molecules.
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Affiliation(s)
- Anthony Behin
- APHP, Centre de Référence des Maladies Neuromusculaires Nord/Est/Ile-de-France, Institut de Myologie, GH Pitié-Salpêtrière, Paris, France.,AIM, Institut de Myologie, Paris, France
| | - Rozen Le Panse
- INSERM U974, Paris, France.,UPMC Sorbonne Université, Paris, France.,AIM, Institut de Myologie, Paris, France
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33
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Detection of human parvovirus B19 infection in the thymus of patients with thymic hyperplasia-associated myasthenia gravis. Clin Microbiol Infect 2018; 25:109.e7-109.e12. [PMID: 29649594 DOI: 10.1016/j.cmi.2018.03.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 03/11/2018] [Accepted: 03/25/2018] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To investigate the association between myasthenia gravis (MG) and human parvovirus B19 (B19V) infection in the thymus. METHODS The presence of human B19V DNA and protein was assessed in 138 samples-including 68 thymic hyperplasias (39 with MG), 58 thymomas (23 with MG), and 12 normal thymus tissues-using a nested polymerase chain reaction, immunohistochemistry, laser capture microdissection, and sequencing in a double-blinded manner. RESULTS B19V DNA was detected mainly in thymic hyperplasia, and the positivity rate (41.18%, 28/68) was significantly higher than that in thymoma (3.45%, 2/58) (p <0.001) but not that in normal thymic tissues. Correspondingly, the positivity rate in thymic hyperplasia with MG (30.77%, 12/39) was significantly higher than that in thymoma with MG (4.35%, 1/23) (p=0.021). However, it was higher in thymic hyperplasia without MG (55.17%, 16/29) than in thymic hyperplasia with MG (30.77%, 12/39) (p=0.043). Cells in thymic hyperplasia positive for B19V VP1/VP2 protein (63.24%, 43/68) were identified mainly in ectopic germinal centres and thymic corpuscle epithelial cells, but were rare in thymomas (1.72%, 1/58) (p <0.001). Moreover, the positivity rate was significantly higher in thymic hyperplasia with MG (74.36%, 29/39) than in thymic hyperplasia without MG (48.28%, 14/29) (p=0.027). CONCLUSIONS To our knowledge, the present study is the first to show that human B19V infection is closely associated with thymic hyperplasia and thymic-hyperplasia-associated MG, but is not related to thymoma or thymoma-associated MG. The findings reveal a previously unrecognized aetiopathogenic mechanism of thymic-hyperplasia-associated MG, evoking numerous questions that require further investigation.
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Weis CA, Schalke B, Ströbel P, Marx A. Challenging the current model of early-onset myasthenia gravis pathogenesis in the light of the MGTX trial and histological heterogeneity of thymectomy specimens. Ann N Y Acad Sci 2018; 1413:82-91. [DOI: 10.1111/nyas.13563] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 10/23/2017] [Accepted: 10/26/2017] [Indexed: 12/28/2022]
Affiliation(s)
- Cleo-Aron Weis
- Institute of Pathology, University Medical Centre Mannheim; University of Heidelberg; Mannheim Germany
| | - Berthold Schalke
- Department of Neurology, University Hospital Regensburg; University of Regensburg; Regensburg Germany
| | - Philipp Ströbel
- Institute of Pathology, University Medical Center Göttingen; University of Göttingen; Göttingen Germany
| | - Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim; University of Heidelberg; Mannheim Germany
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Ayyar BV, Atassi MZ. Development of humanized scFv antibody fragment(s) that targets and blocks specific HLA alleles linked to myasthenia gravis. Appl Microbiol Biotechnol 2017; 101:8165-8179. [DOI: 10.1007/s00253-017-8557-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 01/13/2023]
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Romi F, Hong Y, Gilhus NE. Pathophysiology and immunological profile of myasthenia gravis and its subgroups. Curr Opin Immunol 2017; 49:9-13. [PMID: 28780294 DOI: 10.1016/j.coi.2017.07.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/07/2017] [Indexed: 01/11/2023]
Abstract
Myasthenia gravis (MG) is an autoimmune antibody-mediated disease characterized by muscle weakness and fatigability. It is believed that the initial steps triggering humoral immunity in MG take place inside thymic tissue and thymoma. The immune response against one or several epitopes expressed on thymic tissue cells spills over to neuromuscular junction components sharing the same epitope causing humoral autoimmunity and antibody production. The main cause of MG is acetylcholine receptor antibodies. However, many other neuromuscular junction membrane protein targets, intracellular and extracellular proteins are suggested to participate in MG pathophysiology. MG should be divided into subgroups based on clinical presentation and immunology. This includes onset age, clinical characteristics, thymic pathology and antibody profile. The immunological profile of these subgroups is determined by the antibodies present.
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Affiliation(s)
- Fredrik Romi
- Department of Neurology, Haukeland University Hospital, Norway.
| | - Yu Hong
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Nils Erik Gilhus
- Department of Neurology, Haukeland University Hospital, Norway; Department of Clinical Medicine, University of Bergen, Bergen, Norway
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Danikowski KM, Jayaraman S, Prabhakar BS. Regulatory T cells in multiple sclerosis and myasthenia gravis. J Neuroinflammation 2017; 14:117. [PMID: 28599652 PMCID: PMC5466736 DOI: 10.1186/s12974-017-0892-8] [Citation(s) in RCA: 241] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/29/2017] [Indexed: 01/09/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic debilitating disease of the central nervous system primarily mediated by T lymphocytes with specificity to neuronal antigens in genetically susceptible individuals. On the other hand, myasthenia gravis (MG) primarily involves destruction of the neuromuscular junction by antibodies specific to the acetylcholine receptor. Both autoimmune diseases are thought to result from loss of self-tolerance, which allows for the development and function of autoreactive lymphocytes. Although the mechanisms underlying compromised self-tolerance in these and other autoimmune diseases have not been fully elucidated, one possibility is numerical, functional, and/or migratory deficits in T regulatory cells (Tregs). Tregs are thought to play a critical role in the maintenance of peripheral immune tolerance. It is believed that Tregs function by suppressing the effector CD4+ T cell subsets that mediate autoimmune responses. Dysregulation of suppressive and migratory markers on Tregs have been linked to the pathogenesis of both MS and MG. For example, genetic abnormalities have been found in Treg suppressive markers CTLA-4 and CD25, while others have shown a decreased expression of FoxP3 and IL-10. Furthermore, elevated levels of pro-inflammatory cytokines such as IL-6, IL-17, and IFN-γ secreted by T effectors have been noted in MS and MG patients. This review provides several strategies of treatment which have been shown to be effective or are proposed as potential therapies to restore the function of various Treg subsets including Tr1, iTr35, nTregs, and iTregs. Strategies focusing on enhancing the Treg function find importance in cytokines TGF-β, IDO, interleukins 10, 27, and 35, and ligands Jagged-1 and OX40L. Likewise, strategies which affect Treg migration involve chemokines CCL17 and CXCL11. In pre-clinical animal models of experimental autoimmune encephalomyelitis (EAE) and experimental autoimmune myasthenia gravis (EAMG), several strategies have been shown to ameliorate the disease and thus appear promising for treating patients with MS or MG.
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Affiliation(s)
- K M Danikowski
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - S Jayaraman
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - B S Prabhakar
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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Hong Y, Skeie GO, Zisimopoulou P, Karagiorgou K, Tzartos SJ, Gao X, Yue YX, Romi F, Zhang X, Li HF, Gilhus NE. Juvenile-onset myasthenia gravis: autoantibody status, clinical characteristics and genetic polymorphisms. J Neurol 2017; 264:955-962. [PMID: 28364296 DOI: 10.1007/s00415-017-8478-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 03/27/2017] [Accepted: 03/28/2017] [Indexed: 01/10/2023]
Abstract
Myasthenia gravis (MG) is an autoimmune disorder mediated by antibodies against proteins at the neuromuscular junction. Juvenile-onset MG (JMG) has been reported to have special characteristics. It is still unclear whether there are any pathogenic and genetic differences between juvenile and adult MG. In this study, we evaluated the clinical characteristics, autoantibody status (antibodies against AChR, MuSK, LRP4, titin and RyR) and genetic susceptibility (CHRNA1, CTLA4 and AIRE) in 114 Chinese JMG patients, and compared with 207 young adult MG patients (onset age 18-40 years). JMG patients were classified into two subgroups: the very early onset group (<8 years) and puberty onset group (8-18 years). The very early onset MG patients had a higher proportion of ocular MG and thymus hyperplasia, compared with puberty onset MG and young adult MG (P < 0.05). AChR antibodies were found in majority of JMG patients and were associated with more severe disease (P < 0.05), while other antibodies were rare in JMG. Moreover, the very early onset MG had a more prominent genetic predisposition than puberty and adult MG, affecting the susceptible genes CHRNA1 and CTLA4. JMG has the same pathogenic background as adult MG, but has typical clinical features and a prominent genetic predisposition in very early onset patients (<8 years). Specific therapeutic considerations are needed.
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Affiliation(s)
- Yu Hong
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Geir Olve Skeie
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Neurology, Haukeland University Hospital, 5021, Bergen, Norway
| | | | - Katerina Karagiorgou
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
- Tzartos NeuroDiagnostics, Athens, Greece
| | - Socrates J Tzartos
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
- Tzartos NeuroDiagnostics, Athens, Greece
| | - Xiang Gao
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Yao-Xian Yue
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, 250012, China
| | - Fredrik Romi
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Neurology, Haukeland University Hospital, 5021, Bergen, Norway
| | - Xu Zhang
- Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Hai-Feng Li
- Department of Neurology, Qilu Hospital of Shandong University, Jinan, 250012, China.
| | - Nils Erik Gilhus
- Department of Clinical Medicine, University of Bergen, Bergen, Norway.
- Department of Neurology, Haukeland University Hospital, 5021, Bergen, Norway.
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Wu X, Tüzün E. Are linear AChR epitopes the real culprit in ocular myasthenia gravis? Med Hypotheses 2017; 99:26-28. [DOI: 10.1016/j.mehy.2016.11.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 11/23/2016] [Indexed: 10/20/2022]
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Karni A, Asmail A, Drory VE, Kolb H, Kesler A. Thymus involvement in myasthenia gravis: Epidemiological and clinical impacts of different self-tolerance breakdown mechanisms. J Neuroimmunol 2016; 298:58-62. [DOI: 10.1016/j.jneuroim.2016.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/02/2016] [Accepted: 07/06/2016] [Indexed: 01/24/2023]
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41
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Hu B, Simon-Keller K, Küffer S, Ströbel P, Braun T, Marx A, Porubsky S. Myf5 and Myogenin in the development of thymic myoid cells - Implications for a murine in vivo model of myasthenia gravis. Exp Neurol 2015; 277:76-85. [PMID: 26708556 DOI: 10.1016/j.expneurol.2015.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 11/24/2015] [Accepted: 12/15/2015] [Indexed: 01/24/2023]
Abstract
Myasthenia gravis (MG) is caused by autoantibodies against the neuromuscular junction of striated muscle. Most MG patients have autoreactive T- and B-cells directed to the acetylcholine receptor (AChR). To achieve immunologic tolerance, developing thymocytes are normally eliminated after recognition of self-antigen-derived peptides. Presentation of muscle-specific antigens is likely achieved through two pathways: on medullary thymic epithelial cells and on medullary dendritic cells cross-presenting peptides derived from a unique population of thymic myoid cells (TMC). Decades ago, it has been hypothesized that TMC play a key role in the induction of immunological tolerance towards skeletal muscle antigens. However, an experimental model to address this postulate has not been available. To generate such a model, we tested the hypothesis that the development of TMC depends on myogenic regulatory factors. To this end, we utilized Myf5-deficient mice, which lack the first wave of muscle cells but form normal skeletal muscles later during development, and Myogenin-deficient mice, which fail to form differentiated myofibers. We demonstrate for the first time that Myf5- and Myogenin-deficient mice showed a partial or complete, respectively, loss of TMC in an otherwise regularly structured thymus. To overcome early postnatal lethality of muscle-deficient, Myogenin-knockout mice we transplanted Myogenin-deficient fetal thymuses into Foxn1(nu/nu) mice that lack their own thymus anlage. We found that the transplants are functional but lack TMC. In combination with established immunization strategies (utilizing AChR or Titin), this model should enable us in the future testing the hypothesis that TMC play an indispensable role in the development of central tolerance towards striated muscle antigens.
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Affiliation(s)
- Bo Hu
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Katja Simon-Keller
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Stefan Küffer
- Institute of Pathology, University of Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Philipp Ströbel
- Institute of Pathology, University of Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Thomas Braun
- Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Stefan Porubsky
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
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Marx A, Porubsky S, Belharazem D, Saruhan-Direskeneli G, Schalke B, Ströbel P, Weis CA. Thymoma related myasthenia gravis in humans and potential animal models. Exp Neurol 2015; 270:55-65. [PMID: 25700911 DOI: 10.1016/j.expneurol.2015.02.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 01/16/2015] [Accepted: 02/04/2015] [Indexed: 02/06/2023]
Abstract
Thymoma-associated Myasthenia gravis (TAMG) is one of the anti-acetylcholine receptor MG (AChR-MG) subtypes. The clinico-pathological features of TAMG and its pathogenesis are described here in comparison with pathogenetic models suggested for the more common non-thymoma AChR-MG subtypes, early onset MG and late onset MG. Emphasis is put on the role of abnormal intratumorous T cell selection and activation, lack of intratumorous myoid cells and regulatory T cells as well as deficient expression of the autoimmune regulator (AIRE) by neoplastic thymic epithelial cells. We review spontaneous and genetically engineered thymoma models in a spectrum of animals and the extensive clinical and immunological overlap between canine, feline and human TAMG. Finally, limitations and perspectives of the transplantation of human and murine thymoma tissue into nude mice, as potential models for TAMG, are addressed.
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Affiliation(s)
- Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 13, D-68167 Mannheim, Germany.
| | - Stefan Porubsky
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 13, D-68167 Mannheim, Germany
| | - Djeda Belharazem
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 13, D-68167 Mannheim, Germany
| | - Güher Saruhan-Direskeneli
- Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, Capa 34093, Istanbul, Turkey.
| | - Berthold Schalke
- Department of Neurology, Bezirkskrankenhaus, University of Regensburg, D-93042 Regensburg, Germany.
| | - Philipp Ströbel
- Institute of Pathology, University of Göttingen, Robert-Koch-Str. 40, D-37075 Göttingen, Germany.
| | - Cleo-Aron Weis
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 13, D-68167 Mannheim, Germany.
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Uzawa A, Kawaguchi N, Kanai T, Himuro K, Oda F, Yoshida S, Yoshino I, Kuwabara S. Two-year outcome of thymectomy in non-thymomatous late-onset myasthenia gravis. J Neurol 2015; 262:1019-23. [DOI: 10.1007/s00415-015-7673-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 02/06/2015] [Accepted: 02/08/2015] [Indexed: 11/24/2022]
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Kadota Y, Horio H, Mori T, Sawabata N, Goto T, Yamashita SI, Nagayasu T, Iwasaki A. Perioperative management in myasthenia gravis: republication of a systematic review and a proposal by the guideline committee of the Japanese Association for Chest Surgery 2014. Gen Thorac Cardiovasc Surg 2015; 63:201-15. [PMID: 25608954 DOI: 10.1007/s11748-015-0518-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Indexed: 01/21/2023]
Abstract
Thymectomy is regarded as a useful therapeutic option for myasthenia gravis (MG), though perioperative management in MG patients is largely empirical. While evidence-based medicine is limited in the perioperative management of MG patients, treatment guidelines are required as a benchmark. We selected issues faced by physicians in clinical practice in the perioperative management of extended thymectomy for MG, and examined them with a review of the literature. The present guidelines have reached the stage of consensus within the Japanese Association for Chest Surgery.
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Affiliation(s)
- Yoshihisa Kadota
- Guidelines Committees of Japanese Association for Chest Surgery, Kyoto, Japan,
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Verbeek S, Vanakker O, Mercelis R, Lipka AF, Haerynck F, Dullaers M, Verloo P, Van Coster R, Verhelst H. Lambert-Eaton myasthenic syndrome in a 13-year-old girl with Xp11.22-p11.23 duplication. Eur J Paediatr Neurol 2014; 18:439-43. [PMID: 24461257 DOI: 10.1016/j.ejpn.2014.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 12/07/2013] [Accepted: 01/05/2014] [Indexed: 01/29/2023]
Abstract
Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease of the presynaptic neuromuscular junction, typically occurring in adults as a paraneoplastic syndrome. Only rare cases have been reported in childhood. In most childhood cases, malignancies have not been detected but a propensity to autoimmune disease was noticed. Nevertheless, little is known about genetic factors that may contribute to the susceptibility of an individual to develop LEMS. We report on a 13-year-old girl, known with the Xp11.22-p11.23 duplication syndrome, who presented with severe non-paraneoplastic LEMS. The potential role of this microduplication syndrome in the development of LEMS is explored. Previous literature review of twelve Xp11.2 duplication syndrome patients showed that three of them suffered from various autoimmune diseases. The common duplicated region in those three patients and the presented case comprises 12 disease-associated genes including the FOXP3 (Forkhead Box P3) and WAS (Wiskott-Aldrich syndrome) gene, both implicated in immune function. However, it is unclear whether increased gene dosage of one or both of these genes can cause susceptibility to autoimmune diseases. In conclusion, the presented case emphasizes that autoimmune disease is a recurrent feature of the Xp11.2 duplication syndrome, which should be considered in the follow-up of these patients. The exact mechanism underlying this autoimmune propensity remains to be elucidated.
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Affiliation(s)
- Sabine Verbeek
- Department of Pediatrics, Division of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Olivier Vanakker
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Rudy Mercelis
- Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - A F Lipka
- Department of Neurology, Leiden University Medical Center, The Netherlands
| | - Filomeen Haerynck
- Department of Pediatrics, Division of Immunology, Ghent University Hospital, Ghent, Belgium
| | - Melissa Dullaers
- Department of Pneumology, Laboratory for Immunoregulation and Mucosal Immunology, Ghent University Hospital, Ghent, Belgium
| | - Patrick Verloo
- Department of Pediatrics, Division of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Rudy Van Coster
- Department of Pediatrics, Division of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium
| | - Helene Verhelst
- Department of Pediatrics, Division of Pediatric Neurology and Metabolism, Ghent University Hospital, Ghent, Belgium.
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Nogales-Gadea G, Ramos-Fransi A, Suárez-Calvet X, Navas M, Rojas-García R, Mosquera JL, Díaz-Manera J, Querol L, Gallardo E, Illa I. Analysis of serum miRNA profiles of myasthenia gravis patients. PLoS One 2014; 9:e91927. [PMID: 24637658 PMCID: PMC3956820 DOI: 10.1371/journal.pone.0091927] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 02/17/2014] [Indexed: 12/14/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease characterized by the presence of autoantibodies, mainly against the acetylcholine receptor (AChR). The mechanisms triggering and maintaining this chronic disease are unknown. MiRNAs are regulatory molecules that play a key role in the immune system and are altered in many autoimmune diseases. The aim of this study was to evaluate miRNA profiles in serum of 61 AChR MG patients. We studied serum from patients with early onset MG (n = 22), late onset MG (n = 27) and thymoma (n = 12), to identify alterations in the specific subgroups. In a discovery cohort, we analysed 381 miRNA arrays from 5 patients from each subgroup, and 5 healthy controls. The 15 patients had not received any treatment. We found 32 miRNAs in different levels in MG and analysed 8 of these in a validation cohort that included 46 of the MG patients. MiR15b, miR122, miR-140-3p, miR185, miR192, miR20b and miR-885-5p were in lower levels in MG patients than in controls. Our study suggests that different clinical phenotypes in MG share common altered mechanisms in circulating miRNAs, with no additional contribution of the thymoma. MG treatment intervention does not modify the profile of these miRNAs. Novel insights into the pathogenesis of MG can be reached by the analysis of circulating miRNAs since some of these miRNAs have also been found low in MG peripheral mononuclear cells, and have targets with important roles in B cell survival and antibody production.
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Affiliation(s)
- Gisela Nogales-Gadea
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Alba Ramos-Fransi
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Xavier Suárez-Calvet
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Miquel Navas
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Ricard Rojas-García
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Jordi Díaz-Manera
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Luis Querol
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Eduard Gallardo
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Isabel Illa
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autonoma de Barcelona, Barcelona, Spain
- CIBER de enfermedades neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
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Vrolix K, Fraussen J, Losen M, Stevens J, Lazaridis K, Molenaar PC, Somers V, Bracho MA, Le Panse R, Stinissen P, Berrih-Aknin S, Maessen JG, Van Garsse L, Buurman WA, Tzartos SJ, De Baets MH, Martinez-Martinez P. Clonal heterogeneity of thymic B cells from early-onset myasthenia gravis patients with antibodies against the acetylcholine receptor. J Autoimmun 2014; 52:101-12. [PMID: 24439114 DOI: 10.1016/j.jaut.2013.12.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 12/12/2013] [Indexed: 10/25/2022]
Abstract
Myasthenia gravis (MG) with antibodies against the acetylcholine receptor (AChR-MG) is considered as a prototypic autoimmune disease. The thymus is important in the pathophysiology of the disease since thymus hyperplasia is a characteristic of early-onset AChR-MG and patients often improve after thymectomy. We hypothesized that thymic B cell and antibody repertoires of AChR-MG patients differ intrinsically from those of control individuals. Using immortalization with Epstein-Barr Virus and Toll-like receptor 9 activation, we isolated and characterized monoclonal B cell lines from 5 MG patients and 8 controls. Only 2 of 570 immortalized B cell clones from MG patients produced antibodies against the AChR (both clones were from the same patient), suggesting that AChR-specific B cells are not enriched in the thymus. Surprisingly, many B cell lines from both AChR-MG and control thymus samples displayed reactivity against striated muscle proteins. Striational antibodies were produced by 15% of B cell clones from AChR-MG versus 6% in control thymus. The IgVH gene sequence analysis showed remarkable similarities, concerning VH family gene distribution, mutation frequency and CDR3 composition, between B cells of AChR-MG patients and controls. MG patients showed clear evidence of clonal B cell expansion in contrast to controls. In this latter aspect, MG resembles multiple sclerosis and clinically isolated syndrome, but differs from systemic lupus erythematosus. Our results support an antigen driven immune response in the MG thymus, but the paucity of AChR-specific B cells, in combination with the observed polyclonal expansions suggest a more diverse immune response than expected.
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Affiliation(s)
- Kathleen Vrolix
- Department of Neuroscience, School of Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Judith Fraussen
- Neuroimmunology group, Biomedical Research Institute and Transnationale Universiteit Limburg, School of Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Mario Losen
- Department of Neuroscience, School of Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Jo Stevens
- Department of Neuroscience, School of Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | | | - Peter C Molenaar
- Department of Neuroscience, School of Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Veerle Somers
- Neuroimmunology group, Biomedical Research Institute and Transnationale Universiteit Limburg, School of Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Maria Alma Bracho
- Centre Superior d'Investigació en Salut Pública (CSISP), Àrea de Genòmica i Salut, Conselleria de Sanitat, Generalitat Valenciana, València, Spain; Institut "Cavanilles" de Biodiversitat i Biologia Evolutiva (ICBiBE), Universitat de València, València, Spain; Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Ministerio de Ciencia e Innovación, Spain
| | - Rozen Le Panse
- UPMC UM 76/INSERM U974/CNRS UMR7215/Institute of Myology, 105 Bd de l'hôpital, Paris, France
| | - Piet Stinissen
- Neuroimmunology group, Biomedical Research Institute and Transnationale Universiteit Limburg, School of Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Sonia Berrih-Aknin
- UPMC UM 76/INSERM U974/CNRS UMR7215/Institute of Myology, 105 Bd de l'hôpital, Paris, France
| | - Jos G Maessen
- Department of Cardiothoracic Surgery, University Hospital, Maastricht, The Netherlands
| | - Leen Van Garsse
- Department of Cardiothoracic Surgery, University Hospital, Maastricht, The Netherlands
| | - Wim A Buurman
- Department of Neuroscience, School of Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands
| | - Socrates J Tzartos
- Department of Biochemistry, Hellenic Pasteur Institute, GR 11521 Athens, Greece
| | - Marc H De Baets
- Department of Neuroscience, School of Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands; Neuroimmunology group, Biomedical Research Institute and Transnationale Universiteit Limburg, School of Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Pilar Martinez-Martinez
- Department of Neuroscience, School of Mental Health and Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 50, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
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48
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Cufi P, Dragin N, Ruhlmann N, Weiss JM, Fadel E, Serraf A, Berrih-Aknin S, Le Panse R. Central role of interferon-beta in thymic events leading to myasthenia gravis. J Autoimmun 2014; 52:44-52. [PMID: 24393484 DOI: 10.1016/j.jaut.2013.12.016] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 12/12/2013] [Indexed: 12/30/2022]
Abstract
The thymus plays a primary role in early-onset Myasthenia Gravis (MG) mediated by anti-acetylcholine receptor (AChR) antibodies. As we recently showed an inflammatory and anti-viral signature in MG thymuses, we investigated in detail the contribution of interferon (IFN)-I and IFN-III subtypes in thymic changes associated with MG. We showed that IFN-I and IFN-III subtypes, but especially IFN-β, induced specifically α-AChR expression in thymic epithelial cells (TECs). We also demonstrated that IFN-β increased TEC death and the uptake of TEC proteins by dendritic cells. In parallel, we showed that IFN-β increased the expression of the chemokines CXCL13 and CCL21 by TECs and lymphatic endothelial cells, respectively. These two chemokines are involved in germinal center (GC) development and overexpressed in MG thymus with follicular hyperplasia. We also demonstrated that the B-cell activating factor (BAFF), which favors autoreactive B-cells, was overexpressed by TECs in MG thymus and was also induced by IFN-β in TEC cultures. Some of IFN-β effects were down-regulated when cell cultures were treated with glucocorticoids, a treatment widely used in MG patients that decreases the number of thymic GCs. Similar changes were observed in vivo. The injections of Poly(I:C) to C57BL/6 mice triggered a thymic overexpression of IFN-β and IFN-α2 associated with increased expressions of CXCL13, CCL21, BAFF, and favored the recruitment of B cells. These changes were not observed in the thymus of IFN-I receptor KO mice injected with Poly(I:C), even if IFN-β and IFN-α2 were overexpressed. Altogether, these results demonstrate that IFN-β could play a central role in thymic events leading to MG by triggering the overexpression of α-AChR probably leading to thymic DC autosensitization, the abnormal recruitment of peripheral cells and GC formation.
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Affiliation(s)
- Perrine Cufi
- INSERM U974, Paris, France; CNRS UMR 7215, Paris, France; UPMC Univ Paris 6, Paris, France; AIM, Institute of Myology, Paris, France
| | - Nadine Dragin
- INSERM U974, Paris, France; CNRS UMR 7215, Paris, France; UPMC Univ Paris 6, Paris, France; AIM, Institute of Myology, Paris, France
| | - Nathalie Ruhlmann
- INSERM U974, Paris, France; CNRS UMR 7215, Paris, France; UPMC Univ Paris 6, Paris, France
| | - Julia Miriam Weiss
- INSERM U974, Paris, France; CNRS UMR 7215, Paris, France; UPMC Univ Paris 6, Paris, France; AIM, Institute of Myology, Paris, France
| | - Elie Fadel
- Marie Lannelongue Hospital, Paris-Sud University, Le Plessis-Robinson, France
| | - Alain Serraf
- Marie Lannelongue Hospital, Paris-Sud University, Le Plessis-Robinson, France; Jacques Cartier Hospital, Massy, France
| | - Sonia Berrih-Aknin
- INSERM U974, Paris, France; CNRS UMR 7215, Paris, France; UPMC Univ Paris 6, Paris, France; AIM, Institute of Myology, Paris, France
| | - Rozen Le Panse
- INSERM U974, Paris, France; CNRS UMR 7215, Paris, France; UPMC Univ Paris 6, Paris, France; AIM, Institute of Myology, Paris, France.
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49
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Yi JS, Guidon A, Sparks S, Osborne R, Juel VC, Massey JM, Sanders DB, Weinhold KJ, Guptill JT. Characterization of CD4 and CD8 T cell responses in MuSK myasthenia gravis. J Autoimmun 2013; 52:130-8. [PMID: 24378287 DOI: 10.1016/j.jaut.2013.12.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 12/08/2013] [Indexed: 01/22/2023]
Abstract
Muscle specific tyrosine kinase myasthenia gravis (MuSK MG) is a form of autoimmune MG that predominantly affects women and has unique clinical features, including prominent bulbar weakness, muscle atrophy, and excellent response to therapeutic plasma exchange. Patients with MuSK MG have predominantly IgG4 autoantibodies directed against MuSK on the postsynaptic muscle membrane. Lymphocyte functionality has not been reported in this condition. The goal of this study was to characterize T cell responses in patients with MuSK MG. Intracellular production of IFN-gamma, TNF-alpha, IL-2, IL-17, and IL-21 by CD4+ and CD8+ T cells was measured by polychromatic flow cytometry in peripheral blood samples from 11 Musk MG patients and 10 healthy controls. Only one MuSK MG patient was not receiving immunosuppressive therapy. Regulatory T cells (Treg) were also included in our analysis to determine if changes in T cell function were due to altered Treg frequencies. CD8+ T cells from MuSK MG patients had higher frequencies of polyfunctional responses than controls, and CD4+ T cells had higher IL-2, TNF-alpha, and IL-17. MuSK MG patients had a higher percentage of CD4+ T cells producing combinations of IFN-gamma/IL-2/TNF-gamma, TNF-alpha/IL-2, and IFN-gamma/TNF-alpha. Interestingly, Treg numbers and CD39 expression were not different from control values. MuSK MG patients had increased frequencies of Th1 and Th17 cytokines and were primed for polyfunctional proinflammatory responses that cannot be explained by a defect in CD39 expression or Treg number.
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Affiliation(s)
- J S Yi
- Division of Surgical Sciences, Department of Surgery, Duke University Medical Center, 204 SORF (Bldg. 41), 915 S. LaSalle Street, Box 2926, Durham, NC 27710, USA
| | - A Guidon
- Neuromuscular Division, Department of Neurology, Duke University Medical Center, DUMC Box 3403, Durham, NC 27710, USA
| | - S Sparks
- Division of Surgical Sciences, Department of Surgery, Duke University Medical Center, 204 SORF (Bldg. 41), 915 S. LaSalle Street, Box 2926, Durham, NC 27710, USA
| | - R Osborne
- Division of Surgical Sciences, Department of Surgery, Duke University Medical Center, 204 SORF (Bldg. 41), 915 S. LaSalle Street, Box 2926, Durham, NC 27710, USA
| | - V C Juel
- Neuromuscular Division, Department of Neurology, Duke University Medical Center, DUMC Box 3403, Durham, NC 27710, USA
| | - J M Massey
- Neuromuscular Division, Department of Neurology, Duke University Medical Center, DUMC Box 3403, Durham, NC 27710, USA
| | - D B Sanders
- Neuromuscular Division, Department of Neurology, Duke University Medical Center, DUMC Box 3403, Durham, NC 27710, USA
| | - K J Weinhold
- Division of Surgical Sciences, Department of Surgery, Duke University Medical Center, 204 SORF (Bldg. 41), 915 S. LaSalle Street, Box 2926, Durham, NC 27710, USA
| | - J T Guptill
- Neuromuscular Division, Department of Neurology, Duke University Medical Center, DUMC Box 3403, Durham, NC 27710, USA.
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50
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Coppedè F, Ricciardi R, Denaro M, De Rosa A, Provenzano C, Bartoccioni E, Baggiani A, Lucchi M, Mussi A, Migliore L. Association of the DNMT3B -579G>T polymorphism with risk of thymomas in patients with myasthenia gravis. PLoS One 2013; 8:e80846. [PMID: 24260492 PMCID: PMC3834310 DOI: 10.1371/journal.pone.0080846] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/12/2013] [Indexed: 01/26/2023] Open
Abstract
Increasing evidence suggests a contribution of epigenetic processes in promoting cancer and autoimmunity. Myasthenia gravis (MG) is an autoimmune disease mediated, in approximately 80% of the patients, by antibodies against the nicotinic acetylcholine receptor (AChR+). Moreover, epithelial tumours (thymomas) are present in about 10-20% of the patients, and there is indication that changes in DNA methylation might contribute to the risk and progression of thymomas. However, the role of epigenetics in MG is still not completely clarified. In the present study we investigated if a common polymorphism (-579G>T: rs1569686) in the promoter of the DNMT3B gene coding for the DNA methyltransferase 3B, an enzyme that mediates DNA methylation, increases the risk to develop MG or MG-associated thymomas. The study polymorphism was selected based on recent reports and a literature meta-analysis suggesting association with increased risk of various types of cancer. We screened 324 AChR+ MG patients (140 males and 184 females, mean age 56.0 ± 16.5 years) and 735 healthy matched controls (294 males and 441 females, mean age 57.3 ± 15.6 years). 94 of the total MG patients had a thymoma. While there was no association with the whole cohort of MG patients, we found a statistically significant association of the DNMT3B-579T allele (OR = 1.51; 95% CI=1.1-2.1, P = 0.01) and the TT homozygous genotype (OR = 2.59; 95% CI=1.4-4.9, P = 0.006) with the risk of thymoma. No association was observed in MG patients without thymoma, even after stratification into clinical subtypes. Present results suggest that the DNMT3B-579T allele might contribute to the risk of developing thymoma in MG patients, particularly in homozygous TT subjects.
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Affiliation(s)
- Fabio Coppedè
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Roberta Ricciardi
- Division of Neurology, Department of Neuroscience, University of Pisa, Pisa, Italy
- Division of Thoracic Surgery, Cardiac and Thoracic Department, University of Pisa, Pisa, Italy
| | - Maria Denaro
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Anna De Rosa
- Division of Neurology, Department of Neuroscience, University of Pisa, Pisa, Italy
| | - Carlo Provenzano
- Institute of General Pathology, Catholic University of Rome, Rome, Italy
| | | | - Angelo Baggiani
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Marco Lucchi
- Division of Thoracic Surgery, Cardiac and Thoracic Department, University of Pisa, Pisa, Italy
| | - Alfredo Mussi
- Division of Thoracic Surgery, Cardiac and Thoracic Department, University of Pisa, Pisa, Italy
| | - Lucia Migliore
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
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