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Sanderson NSR. Complement and myasthenia gravis. Mol Immunol 2022; 151:11-18. [PMID: 36063582 DOI: 10.1016/j.molimm.2022.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/26/2022] [Accepted: 08/28/2022] [Indexed: 11/17/2022]
Abstract
Myasthenia gravis is a neuromuscular disease associated with antibodies against components of the neuromuscular junction, most often against the acetylcholine receptor (AChR). Although several mechanisms have been postulated to explain how these autoantibodies can lead to the pathology of the disease, convincing evidence suggests that destruction of the receptor-bearing postsynaptic membrane by complement membrane attack complex is of central importance. In this review, evidence for the importance of complement, and possible relationships between autoantigen, autoantibodies, complement activation, and the destruction of the membrane are discussed. More recent insights from the results of the complement-inhibiting therapeutic antibody eculizumab are also described, and the mechanisms connecting antibody binding to complement activation are considered from a structural viewpoint.
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Verschuuren JJGM, Palace J, Murai H, Tannemaat MR, Kaminski HJ, Bril V. Advances and ongoing research in the treatment of autoimmune neuromuscular junction disorders. Lancet Neurol 2022; 21:189-202. [DOI: 10.1016/s1474-4422(21)00463-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 11/16/2021] [Accepted: 12/17/2021] [Indexed: 12/14/2022]
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Jiang L, Xu P, Zhang D, Lu J, Chang T, Zhang Y, Wang J. Treatment of myasthenia gravis with the method of tonifying spleen and replenishing qi in traditional Chinese medicine: A protocol for systematic review and meta-analysis. Medicine (Baltimore) 2022; 101:e28530. [PMID: 35060508 PMCID: PMC8772699 DOI: 10.1097/md.0000000000028530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Myasthenia gravis (MG) is an autoimmune disease that is associated with the production of autoantibodies. The symptoms of MG are mainly mediated by pathogenic antibodies directed against nicotinic acetylcholine receptors, resulting in a decrease in the number of acetylcholine receptors molecules on the postsynaptic membrane of the neuromuscular junction endplate, leading to clinical symptoms of muscle fatigue and weakness. At present, traditional Chinese medicine (TCM) treatment of MG has a better effect by tonifying spleen and replenishing qi. The purpose of this study was to systematically evaluate the efficacy and safety of TCM therapy for tonifying spleen and replenishing qi in the treatment of myasthenia gravis. METHODS We searched the following databases from their establishment until December 2021: PubMed, Cochrane Library, EMBASE, Web of Science, Springer, CNKI, Wanfang, China Biomedical Database, China Science and Technology Journal Database, Chinese Knowledge Infrastructure, China Clinical Trial Registry, and Baidu Scholars. The literature search language was limited to Chinese and English, and publication time and status were not limited. Randomized controlled trials (RCTs) were included. Two researchers independently searched and screened the articles, assessed their quality, and used the RevMan 5.4.1 software to perform a meta-analysis of the included literature. RESULTS This study compared the main outcome indicators: efficacy rate, recurrence rate, quality of life, and quantitative myasthenia gravis (QMG). Secondary outcome indicators were the clinical absolute score, TCM syndrome score, serum acetylcholine receptor antibody level, and electromyogram low-frequency repetitive nerve stimulation. CONCLUSION This study aimed to evaluate whether the TCM method of tonifying spleen and replenishing qi is effective in the treatment of MG and to provide evidence-based data. ETHICS AND DISSEMINATION The protocol of the systematic review did not require ethical approval because it did not involve human subjects. This article will be published in peer-reviewed journals and will be presented at conferences.
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Affiliation(s)
- Li Jiang
- College of Traditional Chinese Medicine, Changchun University of Traditional Chinese Medicine, Changchun, Jilin Province, China
| | - Peng Xu
- Brain Disease Center, Affiliated Hospital of Changchun University of Traditional Chinese Medicine, Changchun, Jilin Province, China
| | - Dongmei Zhang
- Scientific Research Department of Affiliated Hospital of Changchun University of Traditional Chinese Medicine, Changchun, Jilin Province, China
| | - Jing Lu
- Research Center of Traditional Chinese Medicine Affiliated to Changchun University of Traditional Chinese Medicine, Changchun, Jilin Province, China
| | - Tianying Chang
- Clinical Trial Center of Affiliated Medicine of Changchun University of Traditional Chinese Medicine, Changchun, Jilin Province, China
| | - Yinbin Zhang
- College of Traditional Chinese Medicine, Changchun University of Traditional Chinese Medicine, Changchun, Jilin Province, China
| | - Jian Wang
- Brain Disease Center, Affiliated Hospital of Changchun University of Traditional Chinese Medicine, Changchun, Jilin Province, China
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Wang Q, Liu Y, Kuang S, Li R, Weng N, Zhou Z. miR-181a Ameliorates the Progression of Myasthenia Gravis by Regulating TRIM9. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2021; 2021:1303375. [PMID: 34925522 PMCID: PMC8677396 DOI: 10.1155/2021/1303375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 09/30/2021] [Indexed: 11/29/2022]
Abstract
Abnormally activated CD4+ T cells are considered to be an important factor in the pathogenesis of myasthenia gravis (MG). In the pathogenesis of MG, the imbalance of proinflammatory cytokines and immune cells maintains the imbalance of immune response and inflammatory microenvironment. Studies have shown that miRNA is involved in the pathogenesis of MG. In our experiment, we extracted peripheral blood mononuclear cells (PBMCs) from MG patients and detected the expression of miR-181a and TRIM9 in PBMCs by qRT-PCR. In vitro experiments were conducted to explore the regulatory mechanism of miR-181a on target genes and its influence on inflammatory factors related to MG disease. Experimental autoimmune myasthenia gravis (EAMG) model mice are established, and the effects of miR-181a on EAMG symptoms and inflammatory factors are explored through in vivo experiments. According to a total of 40 EAMG mice that were successfully modeled, all EAMG mice showed symptoms of muscle weakness; their diet was reduced; their weight gain was slow; and even weight loss occurred. In MG patients and EAMG mice, the expression of miR-181a was low and TRIM9 was highly expressed. Bioinformatics website and dual-luciferase report analysis of miR-181a had a targeting relationship with TRIM9, and miR-181a could target the expression of TRIM9. After upregulating miR-181a or interfering with TRIM9, serum miR-181a in EAMG mice was significantly upregulated; TRIM9 was significantly downregulated; its clinical symptoms were reduced; and the expression of inflammatory factors was reduced. The study finally learned that miR-181a can reduce the level of MG inflammatory factors by targeting the expression of TRIM9 and has the effect of improving the symptoms of MG.
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Affiliation(s)
- Qiang Wang
- The Second Clinical Medical College of Guizhou University of Traditional Chinese Medicine, Guiyang 550002, Guizhou, China
| | - Yunquan Liu
- The Second Clinical Medical College of Guizhou University of Traditional Chinese Medicine, Guiyang 550002, Guizhou, China
| | - Shixiang Kuang
- The Second Clinical Medical College of Guizhou University of Traditional Chinese Medicine, Guiyang 550002, Guizhou, China
| | - Ruozhao Li
- The Second Clinical Medical College of Guizhou University of Traditional Chinese Medicine, Guiyang 550002, Guizhou, China
| | - Ning Weng
- The Second Clinical Medical College of Guizhou University of Traditional Chinese Medicine, Guiyang 550002, Guizhou, China
| | - Zhichao Zhou
- Department of Neurology, Zhuji Affiliated Hospital of Shaoxing University, Zhuji 311800, Zhejiang, China
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Evoli A, Spagni G, Monte G, Damato V. Heterogeneity in myasthenia gravis: considerations for disease management. Expert Rev Clin Immunol 2021; 17:761-771. [PMID: 34043932 DOI: 10.1080/1744666x.2021.1936500] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Introduction: Myasthenia gravis is a rare disease of the neuromuscular junction and a prototype of B cell-driven immunopathology. Pathogenic antibodies target post-synaptic transmembrane proteins, most commonly the nicotinic acetylcholine receptor and the muscle-specific tyrosine kinase, inducing end-plate alterations and neuromuscular transmission impairment. Several clinical subtypes are distinct on the basis of associated antibodies, age at symptom onset, thymus pathology, genetic factors, and weakness distribution. These subtypes have distinct pathogenesis that can account for different responses to treatment. Conventional therapy is based on the use of symptomatic agents, steroids, immunosuppressants and thymectomy. Of late, biologics have emerged as effective therapeutic options.Areas covered: In this review, we will discuss the management of myasthenia gravis in relation to its phenotypic and biological heterogeneity, in the light of recent advances in the disease immunopathology, new diagnostic tools, and results of clinical trialsExpert opinion: Clinical management is shaped on serological subtype, and patient age at onset, lifestyle and comorbidities, balancing therapeutic needs and safety. Although reliable biomarkers predictive of clinical and biologic outcome are still lacking, recent developments promise a more effective and safe treatment. Disease subtyping according to serological testing and immunopathology is crucial to the appropriateness of clinical management.
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Affiliation(s)
- Amelia Evoli
- Dipartimento di Neuroscienze, Università Cattolica Del Sacro Cuore, Rome, Italy.,Unità Operativa Complessa di Neurologia, Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Rome, Italy
| | - Gregorio Spagni
- Dipartimento di Neuroscienze, Università Cattolica Del Sacro Cuore, Rome, Italy
| | - Gabriele Monte
- Dipartimento di Neuroscienze, Università Cattolica Del Sacro Cuore, Rome, Italy
| | - Valentina Damato
- Dipartimento di Neuroscienze, Università Cattolica Del Sacro Cuore, Rome, Italy
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Lazaridis K, Tzartos SJ. Myasthenia Gravis: Autoantibody Specificities and Their Role in MG Management. Front Neurol 2020; 11:596981. [PMID: 33329350 PMCID: PMC7734299 DOI: 10.3389/fneur.2020.596981] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/30/2020] [Indexed: 12/11/2022] Open
Abstract
Myasthenia gravis (MG) is the most common autoimmune disorder affecting the neuromuscular junction, characterized by skeletal muscle weakness and fatigability. It is caused by autoantibodies targeting proteins of the neuromuscular junction; ~85% of MG patients have autoantibodies against the muscle acetylcholine receptor (AChR-MG), whereas about 5% of MG patients have autoantibodies against the muscle specific kinase (MuSK-MG). In the remaining about 10% of patients no autoantibodies can be found with the classical diagnostics for AChR and MuSK antibodies (seronegative MG, SN-MG). Since serological tests are relatively easy and non-invasive for disease diagnosis, the improvement of methods for the detection of known autoantibodies or the discovery of novel autoantibody specificities to diminish SN-MG and to facilitate differential diagnosis of similar diseases, is crucial. Radioimmunoprecipitation assays (RIPA) are the staple for MG antibody detection, but over the past years, using cell-based assays (CBAs) or improved highly sensitive RIPAs, it has been possible to detect autoantibodies in previously SN-MG patients. This led to the identification of more patients with antibodies to the classical antigens AChR and MuSK and to the third MG autoantigen, the low-density lipoprotein receptor-related protein 4 (LRP4), while antibodies against other extracellular or intracellular targets, such as agrin, Kv1.4 potassium channels, collagen Q, titin, the ryanodine receptor and cortactin have been found in some MG patients. Since the autoantigen targeted determines in part the clinical manifestations, prognosis and response to treatment, serological tests are not only indispensable for initial diagnosis, but also for monitoring treatment efficacy. Importantly, knowing the autoantibody profile of MG patients could allow for more efficient personalized therapeutic approaches. Significant progress has been made over the past years toward the development of antigen-specific therapies, targeting only the specific immune cells or autoantibodies involved in the autoimmune response. In this review, we will present the progress made toward the development of novel sensitive autoantibody detection assays, the identification of new MG autoantigens, and the implications for improved antigen-specific therapeutics. These advancements increase our understanding of MG pathology and improve patient quality of life by providing faster, more accurate diagnosis and better disease management.
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Affiliation(s)
| | - Socrates J Tzartos
- Tzartos NeuroDiagnostics, Athens, Greece.,Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece
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Jia X, Gong L, Zhang J, Lin F, Zhang F, Dong K, Wang S, Lan M, Huang G, Zhang W. Detection of IgM and IgG Antibodies to Human Parvovirus B19 in Sera of Patients with Thymoma-Associated Myasthenia Gravis. Viral Immunol 2020; 34:213-217. [PMID: 33124969 DOI: 10.1089/vim.2020.0126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Much uncertainty still exists about the viral etiology of myasthenia gravis (MG). To address this, we explored the relationship between human parvovirus B19 (PVB19) infection and MG by investigating the presence of PVB19-specific antibodies in serum. A total of 131 patients with MG (including 47 with thymoma-associated MG, 14 with hyperplasia-associated MG, and 70 with unknown thymic lesions) and 172 healthy volunteers were enrolled in this study. Enzyme linked immunosorbent assay was conducted to detect virus-specific antibodies in cell-free serum. The data were analyzed using Pearson chi-square (χ2) and Fisher's exact tests. In the 131 patients with MG, there was no significant difference between male (53.41 ± 14.65 years) and female (50.19 ± 15.28 years) groups regarding mean age (p > 0.05). Among all MG subgroups, the largest age group comprised participants aged 30-60 years. We found that the frequency of detecting immunoglobulin G (IgG) antibodies against PVB19 VP1 and VP2 was significantly higher among patients with MG (68.70%) than in healthy controls (41.86%) (p < 0.001). In particular, the positive rate for anti-PVB19 IgG in patients with thymoma-associated MG (35/47, 74.47%) was significantly higher than that in healthy participants (72/172, 41.86%; p < 0.001). The findings of this study indicate that PVB19 infection may play a role in the etiopathogenesis of MG, particularly in patients with thymoma-associated MG. The study protocol was registered at ClinicalTrials.gov with the identifier ChiCTR-1900023338.
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Affiliation(s)
- Xueying Jia
- Department of Pathology and Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Li Gong
- Department of Pathology and Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Jiarui Zhang
- Department of Pathology and Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Fang Lin
- Department of Laboratory, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Fuqin Zhang
- Department of Pathology and Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Ke Dong
- Department of Laboratory, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Shumei Wang
- Department of Pathology and Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Miao Lan
- Department of Pathology and Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
| | - Gaosheng Huang
- Department of Pathology and Tangdu Hospital, The Fourth Military Medical University, Xi'an, China.,Department of Pathology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Wei Zhang
- Department of Pathology and Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
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Changeux JP. Discovery of the First Neurotransmitter Receptor: The Acetylcholine Nicotinic Receptor. Biomolecules 2020; 10:E547. [PMID: 32260196 PMCID: PMC7226243 DOI: 10.3390/biom10040547] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/04/2020] [Accepted: 03/10/2020] [Indexed: 11/16/2022] Open
Abstract
The concept of pharmacological receptor was proposed at the turn of the 20th century but it took almost 70 years before the first receptor for a neurotransmitter was isolated and identified as a protein. This review retraces the history of the difficulties and successes in the identification of the nicotinic acetylcholine receptor, the first neurotransmitter receptor to be identified.
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Affiliation(s)
- Jean-Pierre Changeux
- Department of Neuroscience, CNRS UMR 3571, Institut Pasteur & Collège de France, 75015 Paris, France
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Defects of CTLA-4 Are Associated with Regulatory T Cells in Myasthenia Gravis Implicated by Intravenous Immunoglobulin Therapy. Mediators Inflamm 2020; 2020:3645157. [PMID: 32148437 PMCID: PMC7042523 DOI: 10.1155/2020/3645157] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 01/24/2020] [Indexed: 12/12/2022] Open
Abstract
Myasthenia gravis (MG) is a CD4+ T cell-dependent autoimmune disease resulting from aberrant immune response mediated by circulating autoantibodies at the neuromuscular junction. Intravenous immunoglobulin (IVIg) is an expensive and commonly used immunotherapeutic approach to treat patients with MG. The mechanisms of actions involved in IVIg treatment, however, remain to be investigated. In an effort to examine the roles of various subsets of CD4+ T cells in the periphery blood of MG and uncover the mechanisms that contribute to the therapeutical effects of IVIg, we first demonstrated that a subset of CD4+ T cells, CTLA-4-expressing regulatory T (Treg) cells, were underrepresented and functionally defective in MG patients. The dynamic profiling during the IVIg therapy course further revealed an inverse relationship between the frequency of CTLA-4+ Treg and the quantitative MG (QMG) score that represents disease severity. Our mechanistic studies indicated that IVIg expands CTLA-4-Treg cells via modulating antigen-presenting dendritic cells (DCs). To determine the molecular defects of CTLA-4 in abnormities of Treg in MG patients, we demonstrated hypermethylation at -658 and -793 CpGs of CTLA-4 promoter in MG Tregs. Interestingly, IVIg therapy significantly reduced the methylation level at these two sites in MG patients. Overall, our study may suggest a role of CTLA-4 in functionally defected Treg cells in MG and its actions involved in IVIg therapy.
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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: 84] [Impact Index Per Article: 16.8] [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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Affiliation(s)
- Amelia Evoli
- Institute of Neurology, Università Cattolica del Sacro Cuore, Roma, Italy
- Fondazione Policlinico Gemelli, IRCCS, Roma, Italy
| | - Elisa Meacci
- Fondazione Policlinico Gemelli, IRCCS, Roma, Italy
- Institute of Thoracic Surgery, Università Cattolica del Sacro Cuore, Roma, Italy
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