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Mangiardi M, Magliozzi A, Colosimo C, Marsili L. Dropped Head Syndrome: The Importance of Neurophysiology in Distinguishing Myasthenia Gravis from Parkinson's Disease. Biomedicines 2024; 12:1833. [PMID: 39200297 PMCID: PMC11352080 DOI: 10.3390/biomedicines12081833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 08/02/2024] [Accepted: 08/07/2024] [Indexed: 09/02/2024] Open
Abstract
Dropped head syndrome (DHS) is characterized by severe forward flexion of the cervical spine due to an imbalance in neck muscle tone. This condition can be linked to various neuromuscular diseases, including myasthenia gravis (MG). On the other hand, Parkinson's disease (PD) patients may show a clinically indistinguishable picture named antecollis, which is caused by increased axial tone, but without muscle weakness. Differentiating between DHS and antecollis is crucial due to their distinct treatment requirements. We present the case of a 71-year-old White male with a one-month history of severe neck flexion, mild dysphagia, and dysphonia. His medical history included diabetes mellitus, coronary artery disease, arterial hypertension, and mild cervical spondylosis. Neurological examination revealed features of Parkinsonism, including hypomimia, asymmetric rigidity, and reduced arm swing. There was significant weakness in his neck extensor muscles, with no signs of ptosis or diplopia. Brain/spine MRI scans were unremarkable, but electromyography showed a reduced compound muscle action potentials amplitude in repetitive nerve stimulation, consistent with MG. High-titer acetylcholine receptor antibodies confirmed the diagnosis. Treatment with pyridostigmine (60 to 120 mg/day) and plasma exchange (daily, for five consecutive days) improved the patient's general condition and neck posture. Concurrently, the patient was diagnosed with PD based on established clinical criteria and improved with carbidopa/levodopa therapy (up to 150/600 mg/daily). This case highlights the rare co-occurrence of MG and PD, emphasizing the need for thorough clinical, neurophysiological, and laboratory evaluations in complex DHS presentations. Managing MG's life-threatening aspects and addressing PD symptoms requires a tailored approach, showcasing the critical role of neurophysiology in accurate diagnosis and effective treatment.
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Affiliation(s)
| | | | - Carlo Colosimo
- Department of Neurology, Santa Maria University Hospital, 05100 Terni, Italy
| | - Luca Marsili
- Gardner Family Center for Parkinson’s Disease and Movement Disorders, Department of Neurology, University of Cincinnati, Cincinnati, OH 45219, USA
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Saccà F, Salort‐Campana E, Jacob S, Cortés‐Vicente E, Schneider‐Gold C. Refocusing generalized myasthenia gravis: Patient burden, disease profiles, and the role of evolving therapy. Eur J Neurol 2024; 31:e16180. [PMID: 38117543 PMCID: PMC11236062 DOI: 10.1111/ene.16180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 11/06/2023] [Accepted: 11/27/2023] [Indexed: 12/21/2023]
Abstract
BACKGROUND AND PURPOSE Generalized myasthenia gravis (gMG) continues to present significant challenges for clinical management due to an unpredictable disease course, frequent disease fluctuations, and varying response to therapy. The recent availability of new pharmacologic therapies presents a valuable opportunity to reevaluate how this disease is classified, assessed, and managed and identify new ways to improve the clinical care of patients with gMG. METHODS Narrative review was made of publications identified via searches of PubMed and selected congresses (January 2000-September 2022). RESULTS New consensus definitions are required to ensure consistency, to better characterize patients, and to identify patients who will benefit from specific drugs and earlier use of these agents. There is a need for more frequent, standardized patient assessment to identify the cause of motor function deficits, provide a clearer picture of the disease burden and its impact on daily living and quality of life (QoL), and better support treatment decision-making. Novel approaches that target different components of the immune system will play a role in more precise treatment of patients with gMG, alongside the development of new algorithms to guide individualized patient management. CONCLUSIONS gMG has a physical, mental, and social impact, resulting in a considerable burden of disease and substantially decreased QoL, despite standard treatments. The availability of novel, targeted treatments that influence key pathological mediators of gMG, together with new biomarkers, offers the potential to optimize patient management and ultimately enables a greater number of patients to achieve minimal manifestation status and a reduced burden of disease.
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Affiliation(s)
- Francesco Saccà
- Department of Neuroscience, Reproductive Science and OdontostomatologyFederico II UniversityNaplesItaly
| | - Emmanuelle Salort‐Campana
- Reference Center of Neuromuscular Disorders and ALS, Timone University HospitalAssistance Publique–Hopitaux de MarseilleMarseilleFrance
| | - Saiju Jacob
- Institute of Immunology and ImmunotherapyUniversity of BirminghamBirminghamUK
| | - Elena Cortés‐Vicente
- Neuromuscular Diseases Unit, Department of NeurologyHospital de la Santa Creu i Sant Pau and Biomedical Research Institute Sant PauBarcelonaSpain
- Centro de Investigación Biomédica en Red de Enfermedades RarasInstituto de Salud Carlos IIIMadridSpain
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Fan YF, Tu SJ, Liu Y, Li XM, Liu TJ, Zhou LY. Investigation of the differential susceptibility of extraocular muscles in patients diagnosed with ocular myasthenia gravis based on the computerized diplopia test and the Ocular Motor Nerve Palsy Scale. Front Neurol 2024; 15:1353248. [PMID: 38872815 PMCID: PMC11169849 DOI: 10.3389/fneur.2024.1353248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 05/17/2024] [Indexed: 06/15/2024] Open
Abstract
Introduction The pattern of extraocular muscle involvement in ocular myasthenia gravis varies across different reports, diverging from our own observations. Thus, we employed two novel tools to discern this pattern. Methods A retrospective analysis was conducted to collect and organize clinical data from 43 patients diagnosed with ocular myasthenia gravis. Each patient underwent both the computerized diplopia test and the Ocular Motor Nerve Palsy Scale assessment to evaluate the involvement of extraocular muscles. Results Among the patients, there were 30 male and 13 female individuals, with a total of 113 affected extraocular muscles identified. Among all the affected extraocular muscles, the involvement of the levator palpebrae superioris muscle accounted for 35.40%, medial rectus muscle 7.7%, lateral rectus muscle 16.81%, superior rectus muscle 13.27%, inferior rectus muscle 12.39%, superior oblique muscle 1.77%, and inferior oblique muscle 2.65% of the total affected extraocular muscles. The positivity rates of the Neostigmine test were 89.19%, AChR antibody detection was 59.38%, and repetitive nerve stimulation was 34.38%. The AChR antibody positive rate among patients with only diplopia was 100%; among those with only ptosis, it was 80%; and among those with both diplopia and ptosis, it was 86.67%. Conclusion The involvement of the extraocular muscles is not uniform. The levator palpebrae superioris exhibits the highest incidence rate, followed by the four rectus muscles and two oblique muscles. The inferior oblique involvement typically occurs when four or more EOMs are affected. Moreover, the levator palpebrae superioris and medial rectus show a higher tendency for bilateral involvement compared with other extraocular muscles.
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Affiliation(s)
- Yi-fei Fan
- Ocular Motility Disorder Treatment & Rehabilitation Center, Department of Acupuncture, Harbin Medical University, Harbin, Heilongjiang, China
| | - Sai-jun Tu
- Ocular Motility Disorder Treatment & Rehabilitation Center, Department of Acupuncture, Harbin Medical University, Harbin, Heilongjiang, China
| | - Yani Liu
- Ocular Motility Disorder Treatment & Rehabilitation Center, Department of Acupuncture, Harbin Medical University, Harbin, Heilongjiang, China
| | - Xue-mei Li
- The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Tie-juan Liu
- The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Ling-yun Zhou
- The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
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Wang H, van de Bovenkamp FS, Dijkstra DJ, Abendstein L, Borggreven NV, Pool J, Zuijderduijn R, Gstöttner C, Gelderman KA, Damelang T, Vidarsson G, Blom AM, Domínguez-Vega E, Parren PWHI, Sharp TH, Trouw LA. Targeted complement inhibition using bispecific antibodies that bind local antigens and endogenous complement regulators. Front Immunol 2024; 15:1288597. [PMID: 38817607 PMCID: PMC11137741 DOI: 10.3389/fimmu.2024.1288597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 04/17/2024] [Indexed: 06/01/2024] Open
Abstract
Complement activation protects against infection but also contributes to pathological mechanisms in a range of clinical conditions such as autoimmune diseases and transplant rejection. Complement-inhibitory drugs, either approved or in development, usually act systemically, thereby increasing the risk for infections. We therefore envisioned a novel class of bispecific antibodies (bsAbs) which are capable of site-directed complement inhibition by bringing endogenous complement regulators in the vicinity of defined cell surface antigens. Here, we analyzed a comprehensive set of obligate bsAbs designed to crosslink a specific target with either complement regulator factor H (FH) or C4b-binding protein (C4BP). The bsAbs were assessed for their capacity to inhibit complement activation and cell lysis in an antigen-targeted manner. We observed that the bsAbs inhibited classical, lectin, and alternative pathway complement activation in which sufficient endogenous serum FH and C4BP could be recruited to achieve local inhibition. Importantly, the bsAbs effectively protected antigen-positive liposomes, erythrocytes, and human leukocytes from complement-mediated lysis. In conclusion, localized complement inhibition by bsAbs capable of recruiting endogenous human complement regulators (such as FH or C4BP) to cell surfaces potentially provides a novel therapeutic approach for the targeted treatment of complement-mediated diseases.
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Affiliation(s)
- Haiyu Wang
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Douwe J. Dijkstra
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Leoni Abendstein
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | | | - Jos Pool
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Rob Zuijderduijn
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
| | - Christoph Gstöttner
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, Netherlands
| | | | - Timon Damelang
- Sanquin Research, Department of Experimental Immunohematology, Amsterdam, Netherlands
- Department of Biomolecular Mass Spectrometry and Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Gestur Vidarsson
- Sanquin Research, Department of Experimental Immunohematology, Amsterdam, Netherlands
- Department of Biomolecular Mass Spectrometry and Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands
| | - Anna M. Blom
- Department of Translational Medicine, Section of Medical Protein Chemistry, Lund University, Malmö, Sweden
| | - Elena Domínguez-Vega
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, Netherlands
| | - Paul W. H. I. Parren
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
- Gyes BV, Utrecht, Netherlands
| | - Thomas H. Sharp
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Leendert A. Trouw
- Department of Immunology, Leiden University Medical Center, Leiden, Netherlands
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Benlghazi A, Messaoudi H, Belouad M, Bouhtouri Y, Benali S, Rachid AB, El Mangoub F, Elhassani MM, Kouach J. Myasthenia gravis and pregnancy: Lessons learned from a complex a case report. SAGE Open Med Case Rep 2024; 12:2050313X241253998. [PMID: 38764915 PMCID: PMC11100404 DOI: 10.1177/2050313x241253998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 04/23/2024] [Indexed: 05/21/2024] Open
Abstract
Myasthenia gravis primarily affects young adults, with a higher incidence in women, particularly between the ages of 20 and 30. When a young woman with myasthenia gravis contemplates pregnancy, healthcare providers must consider the potential implications. The interplay between hormonal factors and changes in the immune system establishes a complex relationship between myasthenia gravis and pregnancy. On one hand, pregnancy can alter the course of the disease, while on the other hand, the disease can impact the progression of the pregnancy and the well-being of the fetus. In this case report, we present the case of a 28-year-old woman suffering from myasthenia gravis who had undergone a thymectomy 5 years ago and was being treated with an acetylcholinesterase inhibitor. After a planned conception, the patient presented a relapse of her disease during the third trimester of pregnancy, with the onset of severe hydramnios. This observation highlights a specific case of decompensation of myasthenia gravis during pregnancy, associated with the presence of severe hydramnios. Subsequently, we delve into the existing literature to examine the reciprocal influence between myasthenia gravis and pregnancy, as well as the effects of anti-myasthenic treatments on pregnancy outcomes.
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Affiliation(s)
- Abdelhamid Benlghazi
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Hamza Messaoudi
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Moad Belouad
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Yassine Bouhtouri
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Saad Benali
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Ait Bouhou Rachid
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Fatima El Mangoub
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Moulay Mehdi Elhassani
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - Jaouad Kouach
- Department of Gynecology-Obstetrics, Mohammed V Military University Hospital, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
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Zhou G, Wang S, Lin L, Lu K, Lin Z, Zhang Z, Zhang Y, Cheng D, Szeto K, Peng R, Luo C. Screening for immune-related biomarkers associated with myasthenia gravis and dilated cardiomyopathy based on bioinformatics analysis and machine learning. Heliyon 2024; 10:e28446. [PMID: 38571624 PMCID: PMC10988011 DOI: 10.1016/j.heliyon.2024.e28446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/05/2024] Open
Abstract
Background We aim to investigate genes associated with myasthenia gravis (MG), specifically those potentially implicated in the pathogenesis of dilated cardiomyopathy (DCM). Additionally, we seek to identify potential biomarkers for diagnosing myasthenia gravis co-occurring with DCM. Methods We obtained two expression profiling datasets related to DCM and MG from the Gene Expression Omnibus (GEO). Subsequently, we conducted differential gene expression analysis and weighted gene co-expression network analysis (WGCNA) on these datasets. The genes exhibiting differential expression common to both DCM and MG were employed for protein-protein interaction (PPI), Gene Ontology (GO) enrichment analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Additionally, machine learning techniques were employed to identify potential biomarkers and develop a diagnostic nomogram for predicting MG-associated DCM. Subsequently, the machine learning results underwent validation using an external dataset. Finally, gene set enrichment analysis (GSEA) and machine algorithm analysis were conducted on pivotal model genes to further elucidate their potential mechanisms in MG-associated DCM. Results In our analysis of both DCM and MG datasets, we identified 2641 critical module genes and 11 differentially expressed genes shared between the two conditions. Enrichment analysis disclosed that these 11 genes primarily pertain to inflammation and immune regulation. Connectivity map (CMAP) analysis pinpointed SB-216763 as a potential drug for DCM treatment. The results from machine learning indicated the substantial diagnostic value of midline 1 interacting protein1 (MID1IP1) and PI3K-interacting protein 1 (PIK3IP1) in MG-associated DCM. These two hub genes were chosen as candidate biomarkers and employed to formulate a diagnostic nomogram with optimal diagnostic performance through machine learning. Simultaneously, single-gene GSEA results and immune cell infiltration analysis unveiled immune dysregulation in both DCM and MG, with MID1IP1 and PIK3IP1 showing significant associations with invasive immune cells. Conclusion We have elucidated the inflammatory and immune pathways associated with MG-related DCM and formulated a diagnostic nomogram for DCM utilizing MID1IP1/PIK3IP1. This contribution offers novel insights for prospective diagnostic approaches and therapeutic interventions in the context of MG coexisting with DCM.
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Affiliation(s)
- Guiting Zhou
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Shushu Wang
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Liwen Lin
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Kachun Lu
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhichao Lin
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ziyan Zhang
- Zhongshan Traditional Chinese Medicine Hospital, Zhongshan, China
| | - Yuling Zhang
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Danling Cheng
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - KaMan Szeto
- The First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Rui Peng
- Shunde Hospital of Guangzhou University of Chinese Medicine, Foshan, China
| | - Chuanjin Luo
- Cardiology Center, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangdong Clinical Research Academy of Chinese Medicine, Guangzhou, China
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Sheng D, Wang S, Li P, Li J, Xiao Z, Lv H, Liu W, Xiao B, Zhou L. Evidence for genetic causal relationships between gut microbiome, metabolites, and myasthenia gravis: a bidirectional Mendelian randomization study. Front Immunol 2023; 14:1279845. [PMID: 38179043 PMCID: PMC10764630 DOI: 10.3389/fimmu.2023.1279845] [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: 09/06/2023] [Accepted: 12/11/2023] [Indexed: 01/06/2024] Open
Abstract
Background Myasthenia gravis (MG) is an autoimmune disease observed to have connections with gut microbiome. We aimed to systematically assess the causal relationships between gut microbiome, gut microbiome-derived metabolites, and MG using Mendelian randomization (MR) approach. Methods Summary-level genetic datasets from large-scale genome-wide association studies regarding 196 gut microbial taxa from the MiBioGen consortium (n=18,340), 72 derived metabolites from the TwinsUK and KORA studies (n=7,824), and antiacetylcholine receptor (AChR) antibody-positive MG (case=1,873, control=36,370) were employed for MR causal estimates. The inverse-variance weighted (IVW) method was utilized as the main analysis with MR-Egger, maximum likelihood, simple mode, and weighted median as complements. The tests of Cochran's Q, MR-Egger intercept, Steiger, MR-PRESSO and leave-one-out were implemented for sensitivity analyses. Results The forward MR estimates of IVW revealed significant causal associations of the abundance of phylum Actinobacteria, class Gammaproteobacteria, family Defluviitaleac, family Family XIII, and family Peptococcaceae with a reduced risk of MG. Conversely, the abundance of phylum Lentisphaerae, order Mollicutes RF9, order Victivallales, and genus Faecalibacterium was causally associated with an increased risk of MG. The reversed MR analysis proved negative causal correlations between the MG and the abundance of family Peptostreptococcaceae, genus Romboutsia, and genus Subdoligranulum. Regarding the derived metabolites, the IVW estimates revealed that elevated levels of beta-hydroxyisovalerate and methionine were causally associated with a decreased risk of MG, while increased levels of choline and kynurenine were linked to an increased risk of MG. Furthermore, genetically predicted MG was associated with a decreased level of cholesterol. The results obtained from complementary MR methods were similar. These findings remained robust in all sensitivity analyses. Conclusion Our MR findings support the causal effects of specific gut microbiome taxa and derived metabolites on AChR antibody-positive MG, and vice versa, yielding novel insights into prevention and therapy targets of MG. Future studies may be warranted for validation and pursuing the precise mechanisms.
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Affiliation(s)
- Dandan Sheng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Medical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan, China
| | - Song Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Medical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan, China
| | - Peihong Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jiaxin Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zheng Xiao
- Department of Pathology, First Hospital of Changsha, Changsha, Hunan, China
| | - Hui Lv
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Weiping Liu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Luo Zhou
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- National Clinical Medical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan, China
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Saccà F, Pane C, Espinosa PE, Sormani MP, Signori A. Efficacy of innovative therapies in myasthenia gravis: A systematic review, meta-analysis and network meta-analysis. Eur J Neurol 2023; 30:3854-3867. [PMID: 37204031 DOI: 10.1111/ene.15872] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/17/2023] [Accepted: 05/15/2023] [Indexed: 05/20/2023]
Abstract
BACKGROUND AND PURPOSE Therapy for myasthenia gravis (MG) is undergoing a profound change, with new treatments being tested. These include complement inhibitors and neonatal Fc receptor (FcRn) blockers. The aim of this study was to perform a meta-analysis and network meta-analysis of randomized and placebo-controlled trials of innovative therapies in MG with available efficacy data. METHODS We assessed statistical heterogeneity across trials based on the Cochrane Q test and I2 values, and mean differences were pooled using the random-effects model. Treatment efficacy was assessed after 26 weeks of eculizumab and ravulizumab, 28 days of efgartigimod, 43 days of rozanolixizumab, 12 weeks of zilucoplan, and 16, 24 or 52 weeks of rituximab treatment. RESULTS We observed an overall mean Myasthenia Gravis-Activities of Daily Living scale (MG-ADL) score change of -2.17 points (95% confidence interval [CI] -2.67, -1.67; p < 0.001) as compared to placebo. No significant difference emerged between complement inhibitors and anti-FcRn treatment (p = 0.16). The change in Quantitative Myasthenia Gravis scale (QMG) score was -3.46 (95% CI -4.53, -2.39; p < 0.001), with a higher reduction with FcRns (-4.78 vs. -2.60; p < 0.001). Rituximab did not significantly improve the MG-ADL (-0.92 [95% CI -2.24, 0.39]; p = 0.17) or QMG scores (-1.9 [95% CI -3.97, 0.18]; p = 0.07). In the network meta-analysis, efgartigimod had the highest probability of being the best treatment, followed by rozanolixizumab. CONCLUSION Anti-complement and FcRn treatments both proved to be effective in MG patients, whereas rituximab did not show a significant benefit for patients. Within the limitations of this meta-analysis, including efficacy time points, FcRn treatments showed a greater effect on QMG score in the short term. Real-life studies with long-term measurements are needed to confirm our results.
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Affiliation(s)
- Francesco Saccà
- Department of Neurosciences and Reproductive and Odontostomatological Sciences, University "Federico II", Naples, Italy
| | - Chiara Pane
- Department of Neurosciences and Reproductive and Odontostomatological Sciences, University "Federico II", Naples, Italy
| | | | | | - Alessio Signori
- Department of Health Sciences, University of Genoa, Genoa, Italy
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Golfinopoulou R, Giudicelli V, Manso T, Kossida S. Delving into Molecular Pathways: Analyzing the Mechanisms of Action of Monoclonal Antibodies Integrated in IMGT/mAb-DB for Myasthenia Gravis. Vaccines (Basel) 2023; 11:1756. [PMID: 38140161 PMCID: PMC10747390 DOI: 10.3390/vaccines11121756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND Myasthenia Gravis (MG) is a rare autoimmune disease presenting with auto-antibodies that affect the neuromuscular junction. In addition to symptomatic treatment options, novel therapeutics include monoclonal antibodies (mAbs). IMGT®, the international ImMunoGeneTics information system®, extends the characterization of therapeutic antibodies with a systematic description of their mechanisms of action (MOA) and makes them available through its database for mAbs and fusion proteins, IMGT/mAb-DB. METHODS Using available literature data combined with amino acid sequence analyses from mAbs managed in IMGT/2Dstructure-DB, the IMGT® protein database, biocuration allowed us to define in a standardized way descriptions of MOAs of mAbs that target molecules towards MG treatment. RESULTS New therapeutic targets include FcRn and molecules such as CD38, CD40, CD19, MS4A1, and interleukin-6 receptor. A standardized graphical representation of the MOAs of selected mAbs was created and integrated within IMGT/mAb-DB. The main mechanisms involved in these mAbs are either blocking or neutralizing. Therapies directed to B cell depletion and plasma cells have a blocking MOA with an immunosuppressant effect along with Fc-effector function (MS4A1, CD38) or FcγRIIb engager effect (CD19). Monoclonal antibodies targeting the complement also have a blocking MOA with a complement inhibitor effect, and treatments targeting T cells have a blocking MOA with an immunosuppressant effect (CD40) and Fc-effector function (IL6R). On the other hand, FcRn antagonists present a neutralizing MOA with an FcRn inhibitor effect. CONCLUSION The MOA of each new mAb needs to be considered in association with the immunopathogenesis of each of the subtypes of MG in order to integrate the new mAbs as a viable and safe option in the therapy decision process. In IMGT/mAb-DB, mAbs for MG are characterized by their sequence, domains, and chains, and their MOA is described.
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Affiliation(s)
- Rebecca Golfinopoulou
- IMGT, The International ImMunoGeneTics Information System, National Center for Scientific Research (CNRS), Institute of Human Genetics (IGH), University of Montpellier (UM), 34090 Montpellier, France; (R.G.); (V.G.)
- Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 11855 Athens, Greece
| | - Véronique Giudicelli
- IMGT, The International ImMunoGeneTics Information System, National Center for Scientific Research (CNRS), Institute of Human Genetics (IGH), University of Montpellier (UM), 34090 Montpellier, France; (R.G.); (V.G.)
| | - Taciana Manso
- IMGT, The International ImMunoGeneTics Information System, National Center for Scientific Research (CNRS), Institute of Human Genetics (IGH), University of Montpellier (UM), 34090 Montpellier, France; (R.G.); (V.G.)
| | - Sofia Kossida
- IMGT, The International ImMunoGeneTics Information System, National Center for Scientific Research (CNRS), Institute of Human Genetics (IGH), University of Montpellier (UM), 34090 Montpellier, France; (R.G.); (V.G.)
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Chen H, Qiu Y, Yin Z, Wang Z, Tang Y, Ni H, Lu J, Chen Z, Kong Y, Wang Z. Efficacy and safety of the innovative monoclonal antibodies in adults with generalized myasthenia gravis: a Bayesian network analysis. Front Immunol 2023; 14:1280226. [PMID: 38022544 PMCID: PMC10663412 DOI: 10.3389/fimmu.2023.1280226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Accepted: 10/26/2023] [Indexed: 12/01/2023] Open
Abstract
Background A series of clinical trials support the effectiveness of monoclonal antibodies for generalized myasthenia gravis (MG) compared to the placebo, but the priority among drugs remains unclear. Therefore, we conduct a frequentist network meta-analysis (NMA) to compare the relative effects of different drugs for generalized MG. Methods PubMed, Embase, Cochrane Library, and clinicaltrials.gov were systematically searched for eligible studies up to 1 June 2023. The primary outcome was efficacy (Myasthenia Gravis Activities of Daily Living [MG-ADL] score and Quantitative Myasthenia Gravis [QMG] score) and safety (adverse events [AEs]). Mean difference (MD) and risk ratio (RR) with their 95% credible intervals (95%CrIs) were used to show the effect size of continuous and categorical variables, respectively. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results Thirteen studies involving 1167 individuals were identified for NMA. For efficacy outcomes, belimumab, efgartigimod, mezagitamab 600mg, and nipocalimab 60mg/kg were inferior to rozanolixzumab 7mg/kg (MD ranged from 2 to 3.69) and rozanolixzumab 10mg/kg (MD ranged from 2.04 to 3.72) in MG-ADL score, and rozanolixzumab had the highest rank probability (83%) according to the subjective surface under the curve ranking area (SUCRA). For QMG score, batoclimab 340mg (MD ranged from 4.32 to 8.52) and batoclimab 680mg (MD ranged from 4.11 to 9.31) were more effective than placebo and other monoclonal antibodies except for rozanolixzumab, with the highest SUCRA value (93% and 97% respectively). For safety outcomes, belimumab achieved the highest SUCRA value (89.8%) with significant statistical difference compared to rozanolixzumab 7mg/kg (RR 0.08, 95%CrI 0.01 to 0.94) and rozanolixzumab 10mg/kg (RR 0.08, 95%CrI 0.01 to 0.86). Conclusion While all monoclonal antibodies were superior to the placebo, rozanolixzumab and batoclimab might be the most effective for generalized MG. However, rozanolixzumab was associated with higher incidence of AEs. Given the limitations inherent in indirect comparisons, further head-to-head and extensive observational studies are necessary to confirm our findings. Systematic review registration https://inplasy.com/?s=202370112, identifier 202370112.
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Affiliation(s)
- Huiru Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Youjia Qiu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Ziqian Yin
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Zilan Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Yanbing Tang
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu, China
| | - Hanyu Ni
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu, China
| | - Jiaye Lu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Zhouqing Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Yan Kong
- Department of Neurology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Zhong Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
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Pietris J, Madike R, Lam A, Al Sharifi A, Bacchi S, Gupta AK, Kovoor JG, Chan W. Cogan's Lid Twitch for Myasthenia Gravis: A Systematic Review. Semin Ophthalmol 2023; 38:727-736. [PMID: 37166275 DOI: 10.1080/08820538.2023.2211134] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/12/2023]
Abstract
INTRODUCTION Myasthenia gravis is an autoimmune condition affecting the neuromuscular junction of skeletal muscles and may be difficult to diagnose. Several clinical signs may have diagnostic utility, including Cogan's lid twitch. This systematic review aims to synthesise the literature on the accuracy of Cogan's lid twitch for diagnosing myasthenia gravis. METHODS A systematic search of the databases PubMed/MEDLINE, Embase and CENTRAL was performed from inception to August 2022. Risk of bias analysis and data extraction were performed in accordance with the PRISMA 2020 guidelines. RESULTS Seven articles satisfied the inclusion criteria. The results showed that for the diagnosis of myasthenia gravis, Cogan's lid twitch has a sensitivity between 50% and 99% and specificity between 75% and 100%. CONCLUSIONS Cogan's lid twitch is a physical examination finding with moderate diagnostic performance in the diagnosis of myasthenia gravis with ocular involvement. Future studies may seek to evaluate the performance of Cogan's lid twitch in conjunction with other signs of myasthenia gravis with ocular involvements, such as fatigable ptosis or a positive icepack test.
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Affiliation(s)
- James Pietris
- Faculty of Medicine, University of Queensland, Herston, Australia
- Princess Alexandra Hospital, Woolloongabba, Australia
| | - Reema Madike
- Faculty of Medicine, University of Adelaide, Adelaide, SA, Australia
- Department of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA, Australia
| | - Antoinette Lam
- Faculty of Medicine, University of Adelaide, Adelaide, SA, Australia
- Department of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA, Australia
| | - Ali Al Sharifi
- Faculty of Medicine, University of Adelaide, Adelaide, SA, Australia
- Department of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA, Australia
| | - Stephen Bacchi
- Faculty of Medicine, University of Adelaide, Adelaide, SA, Australia
- Department of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA, Australia
| | - Aashray K Gupta
- Faculty of Medicine, University of Adelaide, Adelaide, SA, Australia
- Gold Coast University Hospital, Southport, Australia
| | - Joshua G Kovoor
- Faculty of Medicine, University of Adelaide, Adelaide, SA, Australia
- Department of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA, Australia
| | - WengOnn Chan
- Faculty of Medicine, University of Adelaide, Adelaide, SA, Australia
- Department of Ophthalmology, Royal Adelaide Hospital, Adelaide, SA, Australia
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12
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Leng Y, Li X, Zheng F, Liu H, Wang C, Wang X, Liao Y, Liu J, Meng K, Yu J, Zhang J, Wang B, Tan Y, Liu M, Jia X, Li D, Li Y, Gu Z, Fan Y. Advances in In Vitro Models of Neuromuscular Junction: Focusing on Organ-on-a-Chip, Organoids, and Biohybrid Robotics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2211059. [PMID: 36934404 DOI: 10.1002/adma.202211059] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/18/2023] [Indexed: 06/18/2023]
Abstract
The neuromuscular junction (NMJ) is a peripheral synaptic connection between presynaptic motor neurons and postsynaptic skeletal muscle fibers that enables muscle contraction and voluntary motor movement. Many traumatic, neurodegenerative, and neuroimmunological diseases are classically believed to mainly affect either the neuronal or the muscle side of the NMJ, and treatment options are lacking. Recent advances in novel techniques have helped develop in vitro physiological and pathophysiological models of the NMJ as well as enable precise control and evaluation of its functions. This paper reviews the recent developments in in vitro NMJ models with 2D or 3D cultures, from organ-on-a-chip and organoids to biohybrid robotics. Related derivative techniques are introduced for functional analysis of the NMJ, such as the patch-clamp technique, microelectrode arrays, calcium imaging, and stimulus methods, particularly optogenetic-mediated light stimulation, microelectrode-mediated electrical stimulation, and biochemical stimulation. Finally, the applications of the in vitro NMJ models as disease models or for drug screening related to suitable neuromuscular diseases are summarized and their future development trends and challenges are discussed.
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Affiliation(s)
- Yubing Leng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Xiaorui Li
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Fuyin Zheng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Hui Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Chunyan Wang
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Xudong Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Yulong Liao
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Jiangyue Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Kaiqi Meng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Jiaheng Yu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Jingyi Zhang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Binyu Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Yingjun Tan
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Meili Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Xiaoling Jia
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Deyu Li
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Yinghui Li
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Zhongze Gu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, and with the School of Engineering Medicine, Beihang University, Beijing, 100083, China
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Almodovar JL, Mehrabyan A. Disease-Based Prognostication: Myasthenia Gravis. Semin Neurol 2023; 43:799-806. [PMID: 37751854 DOI: 10.1055/s-0043-1775791] [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: 09/28/2023]
Abstract
Myasthenia gravis (MG) is an acquired autoimmune neuromuscular junction transmission disorder that clinically presents as fluctuating or persistent weakness in various skeletal muscle groups. Neuroprognostication in MG begins with some basic observations on the natural history of the disease and known treatment outcomes. Our objective is to provide a framework that can assist a clinician who encounters the MG patient for the first time and attempts to prognosticate probable outcomes in individual patients. In this review article, we explore clinical type, age of onset, antibody status, severity of disease, thymus pathology, autoimmune, and other comorbidities as prognostic factors in MG.
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Affiliation(s)
- Jorge L Almodovar
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Anahit Mehrabyan
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
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14
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Vinciguerra C, Bevilacqua L, Lupica A, Ginanneschi F, Piscosquito G, Rini N, Rossi A, Barone P, Brighina F, Di Stefano V. Diagnosis and Management of Seronegative Myasthenia Gravis: Lights and Shadows. Brain Sci 2023; 13:1286. [PMID: 37759888 PMCID: PMC10526522 DOI: 10.3390/brainsci13091286] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/30/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Myasthenia gravis (MG) is an antibody-mediated neuromuscular disease affecting the neuromuscular junction. In most cases, autoantibodies can be detected in the sera of MG patients, thus aiding in diagnosis and allowing for early screening. However, there is a small proportion of patients who have no detectable auto-antibodies, a condition termed "seronegative MG" (SnMG). Several factors contribute to this, including laboratory test inaccuracies, decreased antibody production, immunosuppressive therapy, immunodeficiencies, antigen depletion, and immune-senescence. The diagnosis of SnMG is more challenging and is based on clinical features and neurophysiological tests. The early identification of these patients is needed in order to ensure early treatment and prevent complications. This narrative review aims to examine the latest updates on SnMG, defining the clinical characteristics of affected patients, diagnostic methods, management, and therapeutic scenarios.
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Affiliation(s)
- Claudia Vinciguerra
- Neurology Unit, Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, 84131 Salerno, Italy; (C.V.)
| | - Liliana Bevilacqua
- Neurology Unit, Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, 84131 Salerno, Italy; (C.V.)
| | - Antonino Lupica
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy (V.D.S.)
| | - Federica Ginanneschi
- Department of Medical, Surgical and Neurological Sciences, University of Siena, 53100 Siena, Italy; (F.G.)
| | - Giuseppe Piscosquito
- Neurology Unit, Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, 84131 Salerno, Italy; (C.V.)
| | - Nicasio Rini
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy (V.D.S.)
| | - Alessandro Rossi
- Department of Medical, Surgical and Neurological Sciences, University of Siena, 53100 Siena, Italy; (F.G.)
| | - Paolo Barone
- Neurology Unit, Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, 84131 Salerno, Italy; (C.V.)
| | - Filippo Brighina
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy (V.D.S.)
| | - Vincenzo Di Stefano
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy (V.D.S.)
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15
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Pham MC, Masi G, Patzina R, Obaid AH, Oxendine SR, Oh S, Payne AS, Nowak RJ, O'Connor KC. Individual myasthenia gravis autoantibody clones can efficiently mediate multiple mechanisms of pathology. Acta Neuropathol 2023; 146:319-336. [PMID: 37344701 PMCID: PMC11380498 DOI: 10.1007/s00401-023-02603-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/23/2023]
Abstract
Serum autoantibodies targeting the nicotinic acetylcholine receptor (AChR) in patients with autoimmune myasthenia gravis (MG) can mediate pathology via three distinct molecular mechanisms: complement activation, receptor blockade, and antigenic modulation. However, it is unclear whether multi-pathogenicity is mediated by individual or multiple autoantibody clones. Using an unbiased B cell culture screening approach, we generated a library of 11 human-derived AChR-specific recombinant monoclonal autoantibodies (mAb) and assessed their binding properties and pathogenic profiles using specialized cell-based assays. Five mAbs activated complement, three blocked α-bungarotoxin binding to the receptor, and seven induced antigenic modulation. Furthermore, two clonally related mAbs derived from one patient were each highly efficient at more than one of these mechanisms, demonstrating that pathogenic mechanisms are not mutually exclusive at the monoclonal level. Using novel Jurkat cell lines that individually express each monomeric AChR subunit (α2βδε), these two mAbs with multi-pathogenic capacity were determined to exclusively bind the α-subunit of AChR, demonstrating an association between mAb specificity and pathogenic capacity. These findings provide new insight into the immunopathology of MG, demonstrating that single autoreactive clones can efficiently mediate multiple modes of pathology. Current therapeutic approaches targeting only one autoantibody-mediated pathogenic mechanism may be evaded by autoantibodies with multifaceted capacity.
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Affiliation(s)
- Minh C Pham
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
| | - Gianvito Masi
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Rosa Patzina
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Abeer H Obaid
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
- Institute of Biomedical Studies, Baylor University, Waco, TX, 76706, USA
| | - Seneca R Oxendine
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Sangwook Oh
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Aimee S Payne
- Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Richard J Nowak
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Kevin C O'Connor
- Department of Immunobiology, Yale University School of Medicine, 300 George Street-Room 353J, New Haven, CT, 06511, USA.
- Department of Neurology, Yale University School of Medicine, New Haven, CT, 06511, USA.
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Yang J, Wu J, Han T, Lu H, Li F, Li L, Su S, Jiang P, Hou Z. Global research hotspots and frontiers of myasthenia gravis from 2002 to 2021: A bibliometric study. Medicine (Baltimore) 2023; 102:e34002. [PMID: 37327308 PMCID: PMC10270528 DOI: 10.1097/md.0000000000034002] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 05/24/2023] [Indexed: 06/18/2023] Open
Abstract
The objective of this study is to utilize bibliometric and visual analysis techniques to identify hotspots and frontiers of research in myasthenia gravis (MG) and provide valuable references for future research. The Web of Science Core Collection (WoSCC) database was used to retrieve literature data related to MG research, which was then analyzed using VOSviewer 1.6.18, CiteSpace 6.1.R3, and the Online Platform for Bibliometric Analysis. The analysis revealed 6734 publications distributed across 1612 journals and contributed by as many as 24,024 authors affiliated with 4708 institutions across 107 countries/regions. The number of annual publications and citations for MG research has steadily increased over the past 2 decades, with the last 2 years alone witnessing a remarkable increase in annual publications and citations to over 600 and 17,000, respectively. In terms of productivity, the United States emerged as the top producing country, while the University of Oxford ranked first in terms of research institutions. Vincent A was identified as the top contributor in terms of publications and citations. Muscle & Nerve and Neurology ranked first in publications and citations respectively, with clinical neurology and neurosciences among the main subject categories explored. The study also identified pathogenesis, eculizumab, thymic epithelial cells, immune checkpoint inhibitors, thymectomy, MuSK antibodies, risk, diagnosis, and management as the current hot research topics in MG, while burst keywords like quality of life, immune-related adverse events (irAEs), rituximab, safety, nivolumab, cancer, and classification indicated the frontiers of MG research. This study effectively identifies the hotspots and frontiers of MG research, and offers valuable references for researchers interested in this area.
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Affiliation(s)
- Jiali Yang
- Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, China
| | - Jiaojiao Wu
- Xiangyu Pharmaceutical Co., Ltd., Linyi, China
| | - Tingliang Han
- Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, China
| | - Hua Lu
- Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, China
| | - Fangcun Li
- Guilin Municipal Hospital of Traditional Chinese Medicine, Guilin, China
| | - Leilei Li
- Guangxi University of Chinese Medicine, Nanning, China
| | - Shaoting Su
- Guangxi University of Chinese Medicine, Nanning, China
| | - Ping Jiang
- Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhaomeng Hou
- Yancheng TCM Hospital Affiliated to Nanjing University of Chinese Medicine, Yancheng, China
- Guangxi University of Chinese Medicine, Nanning, China
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17
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Kapoor B, Gulati M, Gupta R, Singla RK. Microbiota dysbiosis and myasthenia gravis: Do all roads lead to Rome? Autoimmun Rev 2023; 22:103313. [PMID: 36918089 DOI: 10.1016/j.autrev.2023.103313] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/09/2023] [Indexed: 03/14/2023]
Abstract
Dysregulated immune system with a failure to recognize self from non-self-antigens is one of the common pathogeneses seen in autoimmune diseases. The complex interplay of genetic and environmental factors is important for the occurrence and development of the disease. Among the environmental factors, disturbed gut microbiota (gut dysbiosis) has recently attracted particular attention, especially with advancement in human microbiome research. Although the alterations in microbiota have been seen in various autoimmune diseases, including those of nervous system, there is paucity of information on neuromuscular system diseases. Myasthenia gravis (MG) is one such rare autoimmune disease of neuromuscular junction, and is caused by generation of pathogenic autoantibodies to components of the postsynaptic muscle endplate. In the recent years, accumulating evidences have endorsed the key role of host microbiota, particularly those of gut, in the pathogenesis of MG. Differential microbiota composition, characterized by increased abundance of Fusobacteria, Bacteroidetes, and Proteobacteria, and decreased abundance of Actinobacteria and Firmicutes, has been seen in MG patients in comparison to healthy subjects. Disturbance of microbiota composition, particularly reduced ratio of Firmicutes/Bacteroidetes, alter the gut permeability, subsequently triggering the immunological response. Resultant reduction in levels of short chain fatty acids (SCFAs) is another factor contributing to the immunological response in MG patients. Modulation of gut microbiota via intervention of probiotics, prebiotics, synbiotics, postbiotics (metabiotics), and fecal microbiota transplantation (FMT) is considered to be the futuristic approach for the management of MG. This review summarizes the role of gut microbiota and their metabolites (postbiotics) in the progression of MG. Also, various bacteriotherapeutic approaches involving gut microbiota are discussed for the prevention of MG progression.
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Affiliation(s)
- Bhupinder Kapoor
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, India.
| | - Monica Gulati
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, India; Faculty of Health, Australian Research Centre in Complementary and Integrative Medicine, University of Technology Sydney, NSW 2007, Australia.
| | - Reena Gupta
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, India
| | - Rajeev K Singla
- Institutes for Systems Genetics, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital, Sichuan University, Xinchuan Road, 2222, Chengdu, Sichuan, China; iGlobal Research and Publishing Foundation, New Delhi, India
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18
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Oculomotor fatigability with decrements of saccade and smooth pursuit for diagnosis of myasthenia gravis. J Neurol 2023; 270:2743-2755. [PMID: 36856847 PMCID: PMC10129983 DOI: 10.1007/s00415-023-11611-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/03/2023] [Accepted: 02/04/2023] [Indexed: 03/02/2023]
Abstract
BACKGROUND AND OBJECTIVES As the efficacy of current diagnostic methods for myasthenia gravis (MG) remains suboptimal, there is ongoing interest in developing more effective diagnostic models. As oculomotor fatigability is one of the most common and diagnostic symptoms in MG, we aimed to investigate whether quantitative saccadic and smooth-pursuit fatigability analyses with video-oculography (VOG) are useful for diagnosis of MG. METHODS A convenience cohort of 46 MG patients was recruited prospectively, including 35 with ocular and 11 with generalized MG (mean age, 50.9 ± 14.5 years; 17 females); 24 healthy controls (HCs) (mean age, 50.6 ± 16.3 years; 13 females) also were enrolled. Seventy-five repetitive saccades and smooth pursuits were recorded in ranges of 20° (horizontal plane) and 15° (vertical plane) using a three-dimensional VOG system. Based on the oculomotor range of the second saccade and smooth pursuit and the mean ranges of the last five of each, the estimated decrements (%) reflecting oculomotor fatigability were calculated. RESULTS The baseline oculomotor ranges did not show significant difference between the MG and HCs groups. However, following repetitive saccades and pursuits, the oculomotor ranges were decreased substantially during the last five cycles compared to baseline in the MG group. No such decrements were observed in the HC group (p < 0.01, Mann-Whitney U test). Receiver operating characteristic (ROC) analysis revealed that repetitive vertical saccades yielded the best differentiation between the MG and HC groups, with a sensitivity of 78.3% and specificity of 95.8% when using a decrement with an amplitude of 6.4% as the cutoff. CONCLUSION This study presents an objective and reproducible method for measuring decrements of oculomotor ranges after repetitive saccadic and pursuit movements. Quantification of oculomotor fatigability using VOG could be a sensitive and specific diagnostic tool for MG and allows easy, cost-effective, accurate, and non-invasive measurements. CLASSIFICATION OF EVIDENCE This study provides class III evidence that VOG-based quantification of saccadic and pursuit fatigability accurately identifies patients with MG.
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Kwon YN, Woodhall M, Sung JJ, Kim KK, Lim YM, Kim H, Kim JE, Baek SH, Kim BJ, Park JS, Seok HY, Kim DS, Kwon O, Park KH, Sohn E, Bae JS, Yoon BN, Kim NH, Ahn SW, Choi K, Oh J, Park HJ, Shin KJ, Lee S, Park J, Kim SH, Seok JI, Bae DW, An JY, Joo IS, Choi SJ, Nam TS, Kim S, Park KJ, Kwon KH, Waters P, Hong YH. Clinical pitfalls and serological diagnostics of MuSK myasthenia gravis. J Neurol 2023; 270:1478-1486. [PMID: 36396811 PMCID: PMC9971039 DOI: 10.1007/s00415-022-11458-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/22/2022] [Accepted: 10/25/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUND We aimed to evaluate the diagnostic accuracy of enzyme-linked immunosorbent assay (ELISA) for anti-muscle specific tyrosine kinase (MuSK) antibody (Ab) in a large cohort of anti-acetylcholine receptor (AChR) Ab-negative generalized myasthenia gravis (MG), and also to investigate clinical contexts for the diagnosis of MuSK MG. METHODS A retrospective study of 160 patients with a clinical suspicion of AChR Ab-negative generalized MG was performed. The serum samples were tested for anti-clustered AChR Ab by cell-based assay (CBA), anti-MuSK Ab by ELISA, CBA and/or radioimmunoprecipitation assay (RIPA). Clinical data were compared between anti-MuSK Ab-positive MG and double seronegative (AChR and MuSK) MG groups. RESULTS After excluding non-MG and clustered AChR Ab-positive patients, we identified 89 patients as a cohort of AChR Ab-negative generalized MG. Anti-MuSK Ab was positive by ELISA in 22 (24.7%) patients. While CBA identified five additional anti-MuSK Ab-positive patients, the results of ELISA were mostly consistent with CBA and RIPA with Cohen's kappa of 0.80 and 0.90, respectively (p < 0.001). The most frequent differential diagnosis was motor neuron disease particularly of bulbar onset which showed remarkably overlapping clinical and electrophysiological features with MuSK MG at presentation. CONCLUSION While confirming the highest sensitivity of CBA for detecting anti-MuSK Ab, our results highlight the clinical pitfalls in making a diagnosis of MuSK MG and may support a diagnostic utility of MuSK-ELISA in clinical practice.
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Affiliation(s)
- Young Nam Kwon
- Department of Neurology, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Republic of Korea
- Department of Neurology, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Mark Woodhall
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, Neuroimmunology Group, University of Oxford, John Radcliffe Hospital, Level 5, West Wing, Headley Way, Oxford, OX3 9DU, UK
| | - Jung-Joon Sung
- Department of Neurology, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Neurology, Seoul National University College of Medicine, Neuroscience Research Institute, Seoul National University Medical Research Council, 20 Boramae-Ro 5-Gil, Dongjak-Gu, Seoul, 07061, Republic of Korea
| | - Kwang-Kuk Kim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Young-Min Lim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Hyunjin Kim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jee-Eun Kim
- Department of Neurology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
| | - Seol-Hee Baek
- Department of Neurology, Korea University College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - Byung-Jo Kim
- Department of Neurology, Korea University College of Medicine, Korea University Anam Hospital, Seoul, Republic of Korea
| | - Jin-Sung Park
- Department of Neurology, School of Medicine, Kyungpook National University, Kyungpook National University Chilgok Hospital, Daegu, Republic of Korea
| | - Hung Youl Seok
- Department of Neurology, Dongsan Hospital, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Dae-Seong Kim
- Department of Neurology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Ohyun Kwon
- Department of Neurology, Uijeongbu Eulji Medical Center, Eulji University School of Medicine, Uijeongbu, Republic of Korea
| | - Kee Hong Park
- Department of Neurology, Seoul Medical Center, Seoul, Republic of Korea
| | - Eunhee Sohn
- Department of Neurology, Chungnam National University College of Medicine, Chungnam National University Hospital, Daejeon, Republic of Korea
| | - Jong Seok Bae
- Department of Neurology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea
| | - Byung-Nam Yoon
- Department of Neurology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Republic of Korea
| | - Nam-Hee Kim
- Department of Neurology, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
| | - Suk-Won Ahn
- Department of Neurology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Kyomin Choi
- Department of Neurology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Jeeyoung Oh
- Department of Neurology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Hyung Jun Park
- Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Kyong Jin Shin
- Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea
| | - Sanggon Lee
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Jinseok Park
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Seung Hyun Kim
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Jung Im Seok
- Department of Neurology, School of Medicine, Catholic University of Daegu, Daegu, Republic of Korea
| | - Dae Woong Bae
- Department of Neurology, College of Medicine, St. Vincent Hospital, The Catholic University of Korea, Suwon, Republic of Korea
| | - Jae Young An
- Department of Neurology, College of Medicine, St. Vincent Hospital, The Catholic University of Korea, Suwon, Republic of Korea
| | - In Soo Joo
- Department of Neurology, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Seok-Jin Choi
- Department of Neurology, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Tai-Seung Nam
- Department of Neurology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Sunyoung Kim
- Department of Neurology, University of Ulsan College of Medicine, Ulsan, Republic of Korea
| | - Ki-Jong Park
- Department of Neurology, College of Medicine, Gyeongsang National University, Gyeonsang Institute of Health Science, Jinju, Republic of Korea
| | - Ki-Han Kwon
- Department of Neurology, Hallym University Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Republic of Korea
| | - Patrick Waters
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, Neuroimmunology Group, University of Oxford, John Radcliffe Hospital, Level 5, West Wing, Headley Way, Oxford, OX3 9DU, UK.
| | - Yoon-Ho Hong
- Department of Neurology, Seoul National University Seoul Metropolitan Government Boramae Medical Center, Seoul, Republic of Korea.
- Department of Neurology, Seoul National University College of Medicine, Neuroscience Research Institute, Seoul National University Medical Research Council, 20 Boramae-Ro 5-Gil, Dongjak-Gu, Seoul, 07061, Republic of Korea.
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Long-Term Remission With Low-Dose Rituximab in Myasthenia Gravis: A Retrospective Study. J Clin Neuromuscul Dis 2022; 24:18-25. [PMID: 36005470 DOI: 10.1097/cnd.0000000000000420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJETIVE Rituximab (RTX) is a therapeutic option, for patients with myasthenia gravis (MG) not responding to conventional immunosuppressive treatment. In this cohort, we evaluated long-term efficacy of RTX in the treatment of refractory generalized MG. METHODS A retrospective study was performed in adult patients with refractory generalized MG and at least 24 months of follow-up, between January/2015 and October/2021. The Myasthenia Gravis Status and Treatment Intensity Score was used to assess outcomes, and CD19/CD20+ B-cell counts were monitored. RESULTS Sixteen patients with MG (8 antiacetylcholine receptor+ and 8 muscle-specific antikinase+; mean age 45.5 ± 16.2 years) treated with low-dose RTX protocols were included. CD19/CD20 levels remained undetectable 12 months after induction, and no new relapses were observed during follow-up. CONCLUSIONS Low-dose RTX infusions were sufficient to achieve undetectable CD19/20 cell counts and sustained clinical remission. In low and middle-income countries, the impact of low-dose RTX therapy represents a paradigm shift in decision-making for long-term treatment.
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Zouvelou V, Michail M, Belimezi M, Haroniti A, Zisimopoulou P. Characterization of the nicotinic acetylcholine receptor antibodies after an unexpected increase of antibody titer in thymoma associated myasthenia gravis patients. Neuromuscul Disord 2022; 32:847-850. [PMID: 36028368 DOI: 10.1016/j.nmd.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/25/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022]
Abstract
Two thymoma-associated myasthenia gravis patients with chronic well-controlled disease but an unexpected increase in anti-nAChR autoantibodies titer are reported. The specificity of anti-nAChR autoantibodies directed against extracellular parts of the receptor was studied in order to investigate the discrepancy between clinical and immunological status. Analysis of the anti-nAChR autoantibodies recognizing the extracellular parts of the nAChR revealed that when the concentration of anti-nAChR autoantibodies titer increased both patients had non-anti-α1 autoantibodies. Since the clinical profile of both patients remained unchanged, the increase of non-anti-α1 autoantibodies did not affect the 2 patients' disease progression. Thus, immunotherapy modification due to an increase of anti-nAChR autoantibodies titer could be erroneous and potentially harmful.
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Affiliation(s)
- Vasiliki Zouvelou
- 1st Department of Neurology, Eginition Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Michail
- Laboratory of Molecular Neurobiology and Immunology, Hellenic Pasteur Institute, Athens, Greece; Department of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Belimezi
- Diagnostic Department, Hellenic Pasteur Institute, Athens, Greece
| | - Anna Haroniti
- Laboratory of Molecular Neurobiology and Immunology, Hellenic Pasteur Institute, Athens, Greece
| | - Paraskevi Zisimopoulou
- Laboratory of Molecular Neurobiology and Immunology, Hellenic Pasteur Institute, Athens, Greece.
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Risk for generalization in ocular onset myasthenia gravis: experience from a neuro-ophthalmology clinic. Acta Neurol Belg 2022; 122:337-344. [PMID: 33544334 DOI: 10.1007/s13760-020-01582-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/17/2020] [Indexed: 01/13/2023]
Abstract
Conversion to generalized myasthenia gravis (GMG) within the first 2 years has been reported in 18-85% of patients with ocular myasthenia gravis (OMG). The aim of the study was to investigate the risk factors for generalization in patients with OMG admitted to a neuro-ophthalmology clinic and to determine if there were differences between patients with GMG with predominant bulbar (GMG-B) or extremity muscle (GMG-E) involvement according to the 6th and 24th-month Myasthenia Gravis Foundation of America classification ranks. Patients with OMG who were followed-up for at least 24 months were retrospectively analyzed. Demographic, clinical, laboratory features and treatment strategies that can be associated with generalization and time to generalization were evaluated. Of the 139 patients with OMG, 54 (39%) showed generalization with a mean time of 10.3 (range 2-24) months. GMG-B and GMG-E were diagnosed in 31 (22.3%) and 23 patients (16.5%), respectively. Seropositivity for acetylcholine receptor and muscle-specific tyrosine kinase antibodies, abnormal single-fiber electromyography (SFEMG), and the presence of thymic abnormalities (thymoma and hyperplasia) were factors associated with generalization on multivariate analysis without a significant difference between the GMG-B and GMG-E groups. In addition, an abnormal repetitive nerve stimulation test was related to a shortened time to generalization. Bilateral ptosis at onset was found as a risk factor for generalization. In a neuro-ophthalmology clinic, bilateral ptosis as an initial feature of OMG must be approached cautiously because it may be the first sign of impending GMG.
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Salari N, Fatahi B, Bartina Y, Kazeminia M, Fatahian R, Mohammadi P, Shohaimi S, Mohammadi M. Global prevalence of myasthenia gravis and the effectiveness of common drugs in its treatment: a systematic review and meta-analysis. J Transl Med 2021; 19:516. [PMID: 34930325 PMCID: PMC8686543 DOI: 10.1186/s12967-021-03185-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/06/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Myasthenia gravis is a neuromuscular autoimmune disorder characterized by weakness and disability in the voluntary muscles. There have been several preliminary studies on the epidemiology of myasthenia gravis in different parts of the world and the effectiveness of common drugs in its treatment, but there has been no comprehensive study of the efficacy of common drugs in the treatment of myasthenia gravis. Therefore, this study aimed to determine the epidemiology of myasthenia gravis globally and the effectiveness of common drugs in its treatment using systematic review and meta-analysis. METHODS Research studies were extracted from IranDoc, MagIran, IranMedex, SID, ScienceDirect, Web of Sciences (WoS), ProQuest, Medline (PubMed), Scopus and Google Scholar based on Cochran's seven-step guidelines using existing keywords extracted in MeSH browser. The I2 test was used to calculate the heterogeneity of studies, and Begg and Mazumdar rank correlation tests were used to assess publication bias. Data were analyzed using Comprehensive Meta-Analysis software (Version 2). RESULTS In the search for descriptive studies based on the research question, 7374 articles were found. After deleting articles unrelated to the research question, finally, 63 articles with a sample size of 1,206,961,907 people were included in the meta-analysis. The prevalence of MG worldwide was estimated to be 12.4 people (95% CI 10.6-14.5) per 100,000 population. For analytical studies on the effectiveness of common myasthenia gravis drugs, 4672 articles were found initially, and after removing articles unrelated to the research question, finally, 20 articles with a sample size of 643 people in the drug group and 619 people in the placebo group were included in the study. As a result of the combination of studies, the difference between the mean QMGS score index after taking Mycophenolate and Immunoglobulin or plasma exchange drugs in the group of patients showed a significant decrease of 1.4 ± 0.77 and 0.62 ± 0.28, respectively (P < 0.01). CONCLUSION The results of systematic review of drug evaluation in patients with myasthenia gravis showed that Mycophenolate and Immunoglobulin or plasma exchange drugs have positive effects in the treatment of MG. It also represents the positive effect of immunoglobulin or plasma exchange on reducing SFEMG index and QMGS index and the positive effect of Mycophenolate in reducing MG-ADL index, SFEMG and Anti-AChR antibodies index. In addition, based on a meta-analysis of the random-effect model, the overall prevalence of MG in the world is 12.4 people per 100,000 population, which indicates the urgent need for attention to this disease for prevention and treatment.
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Affiliation(s)
- Nader Salari
- Department of Biostatistics, School of Health, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Behnaz Fatahi
- Student Research Committee, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Yalda Bartina
- Department of Translation Studies, Faculty of Literature, Istanbul University, Istanbul, Turkey
| | - Mohsen Kazeminia
- Student Research Committee, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Reza Fatahian
- Department of Neurosurgery, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Payam Mohammadi
- Department of Neurology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Shamarina Shohaimi
- Department of Biology, Faculty of Science, University Putra Malaysia, Serdang, Selangor Malaysia
| | - Masoud Mohammadi
- Cellular and Molecular Research Center, Gerash University of Medical Sciences, Gerash, Iran
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Decker P, Moulinet T, Pontille F, Cravat M, De Carvalho Bittencourt M, Jaussaud R. An updated review of anti-Ro52 (TRIM21) antibodies impact in connective tissue diseases clinical management. Autoimmun Rev 2021; 21:103013. [PMID: 34896652 DOI: 10.1016/j.autrev.2021.103013] [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: 11/05/2021] [Accepted: 12/08/2021] [Indexed: 01/22/2023]
Abstract
Anti-Ro52 (or anti-TRIM21) antibodies are part of the family of anti-Ro/SSA antibodies, historically markers of Sjögren syndrome and systemic lupus erythematosus. Anti-Ro52 antibodies represent one the most frequently encountered autoantibodies in patients with connective tissue disease (primary Sjögren syndrome, systemic lupus erythematosus, systemic sclerosis and idiopathic inflammatory myopathies). Because of their lack of specificity and detection in patients with non-autoimmune disorders, the usefulness of anti-Ro52 testing in connective tissue diseases is still matter of debate among clinicians and immunologists. Autoantibodies are mainly diagnostic markers for autoimmune diseases but some of them can also be directly involved in the generation of tissue damage. Over the past decade several authors reported associations of anti-Ro52 antibodies with some clinical features - especially interstitial lung disease - and survival in patients with connective tissue diseases. There is also a growing evidence of the role of anti-Ro52 antibodies in the pathogenesis of connective tissue diseases. In this review, we comprehensively discuss the clinical associations of anti-Ro52 antibodies in the different connective tissue diseases and the recent advances on their potential role in the inflammatory response.
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Affiliation(s)
- P Decker
- Department of Internal Medicine and Clinical Immunology, Regional Competence Center for Systemic and Autoimmune Rare Diseases, Nancy University Hospital, Lorraine University, Vandoeuvre-lès-Nancy, France.
| | - T Moulinet
- Department of Internal Medicine and Clinical Immunology, Regional Competence Center for Systemic and Autoimmune Rare Diseases, Nancy University Hospital, Lorraine University, Vandoeuvre-lès-Nancy, France; UMR7365, IMoPA, Lorraine University, CNRS, Nancy, France
| | - F Pontille
- Department of Internal Medicine and Clinical Immunology, Regional Competence Center for Systemic and Autoimmune Rare Diseases, Nancy University Hospital, Lorraine University, Vandoeuvre-lès-Nancy, France
| | - M Cravat
- Laboratory of Immunology, Nancy University Hospital, Lorraine University, Vandoeuvre-lès-Nancy, France; UMR7365, IMoPA, Lorraine University, CNRS, Nancy, France
| | - M De Carvalho Bittencourt
- Laboratory of Immunology, Nancy University Hospital, Lorraine University, Vandoeuvre-lès-Nancy, France; UMR7365, IMoPA, Lorraine University, CNRS, Nancy, France
| | - R Jaussaud
- Department of Internal Medicine and Clinical Immunology, Regional Competence Center for Systemic and Autoimmune Rare Diseases, Nancy University Hospital, Lorraine University, Vandoeuvre-lès-Nancy, France
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Comparative Analysis of BIOCHIP Mosaic-Based Indirect Immunofluorescence with Enzyme-Linked Immunosorbent Assay for Diagnosing Myasthenia Gravis. Diagnostics (Basel) 2021; 11:diagnostics11112098. [PMID: 34829445 PMCID: PMC8619605 DOI: 10.3390/diagnostics11112098] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/04/2021] [Accepted: 11/10/2021] [Indexed: 11/17/2022] Open
Abstract
Background: The detection of anti-acetylcholine receptor (AChR) and anti-muscle-specific tyrosine kinase (MuSK) antibodies is useful in myasthenia gravis (MG) diagnosis and management. BIOCHIP mosaic-based indirect immunofluorescence is a novel analytical method, which employs the simultaneous detection of anti-AChR and anti-MuSK antibodies in a single miniature incubation field. In this study, we compare, for the first time, the BIOCHIP MG mosaic with conventional enzyme-linked immunosorbent assay (ELISA) in the diagnosis of MG. Methods: A total of 71 patients with MG diagnosis were included in the study. Anti-AChR and anti-MuSK antibodies were measured separately by two different ELISA and simultaneously by BIOCHIP. The results were then compared. Results: The overall concordance between ELISA and BIOCHIP for anti-AChR reactivity was 74%. Cohen’s kappa was 0.51 (95% CI 0.32–0.71), which corresponds to 90% of the maximum possible kappa (0.57), given the observed marginal frequencies. The overall concordance for anti-MuSK reactivity was 84%. Cohen’s kappa was 0.11 (95% CI 0.00–0.36), which corresponds to 41% of the maximum possible kappa (0.27). Conclusion: The overall concordance among assays is not optimal.
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Nabe Y, Hashimoto T, Tanaka K, Fujita Y, Yoshimatsu K, Nemoto Y, Oyama R, Matsumiya H, Mori M, Kanayama M, Taira A, Shinohara S, Kuwata T, Takenaka M, Tashima Y, Kuroda K, Tanaka F. Relationship between anti-acetylcholine receptor antibodies and the development of post-thymectomy myasthenia gravis in patients with thymoma: a single-center experience. Gland Surg 2021; 10:2408-2413. [PMID: 34527552 DOI: 10.21037/gs-21-287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/16/2021] [Indexed: 12/14/2022]
Abstract
Background Approximately 15-29.6% of patients with thymoma have myasthenia gravis (MG). Some of these patients develop MG after thymectomy despite having no history of MG or related symptoms. Few previous studies have examined the risk factors for the development of post-thymectomy MG in patients with thymoma. Herein, we retrospectively reviewed our institutional experience with patients with thymoma who developed MG after thymectomy. Methods Twenty-six patients with thymoma but without MG, who were tested preoperatively for anti-acetylcholine receptor antibody (anti-AChR-Ab) levels, underwent surgical resection at our hospital between 2013 and 2020. Patients with thymic carcinoma were excluded from the study. We evaluated the association of outcomes with preoperative anti-AChR-Ab levels and post-thymectomy MG. We performed a χ2 test for bivariate analysis of categorical data. Differences were considered significant at P<0.05. Results The characteristics of the 26 patients (median age: 62 years; 8 men, 18 women) were as follows: World Health Organization (WHO) classifications AB (n=8), B1 (n=9), B2 (n=6), B3 (n=1), and others (n=2) and Masaoka stage I (n=12), II (n=9), III (n=3), and IVa (n=2). Among the 26 patients, only five had high (>0.3 nmol/L) preoperative anti-AChR-Ab levels. Post-thymectomy MG occurred in two of the five patients (40%) with high preoperative anti-AChR-Ab levels. A high preoperative serum anti-AChR-Ab titer was significantly associated with post-thymectomy MG (P=0.0267). The anti-AChR-Ab titer was also measured postoperatively in four of the five (80%) patients with high preoperative levels. The anti-AChR-Ab titer decreased in two of these four patients, and neither developed postoperative MG. Conclusions Preoperative and postoperative anti-AChR-Ab positivity might be associated with post-thymectomy MG. Therefore, regular measurement of anti-AChR-Ab levels after thymectomy is required.
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Affiliation(s)
- Yusuke Nabe
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Teppei Hashimoto
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Kanji Tanaka
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Yasuhiro Fujita
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Katsuma Yoshimatsu
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Yukiko Nemoto
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Rintaro Oyama
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Hiroki Matsumiya
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Masataka Mori
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Masatoshi Kanayama
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Akihiro Taira
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Shinji Shinohara
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Taiji Kuwata
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Masaru Takenaka
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Yuko Tashima
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Koji Kuroda
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Fumihiro Tanaka
- Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
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NKT and NKT-like Cells in Autoimmune Neuroinflammatory Diseases-Multiple Sclerosis, Myasthenia Gravis and Guillain-Barre Syndrome. Int J Mol Sci 2021; 22:ijms22179520. [PMID: 34502425 PMCID: PMC8431671 DOI: 10.3390/ijms22179520] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/27/2021] [Accepted: 08/27/2021] [Indexed: 12/14/2022] Open
Abstract
NKT cells comprise three subsets—type I (invariant, iNKT), type II, and NKT-like cells, of which iNKT cells are the most studied subset. They are capable of rapid cytokine production after the initial stimulus, thus they may be important for polarisation of Th cells. Due to this, they may be an important cell subset in autoimmune diseases. In the current review, we are summarising results of NKT-oriented studies in major neurological autoimmune diseases—multiple sclerosis, myasthenia gravis, and Guillain-Barre syndrome and their corresponding animal models.
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Odierna GL, Phillips WD. The Safety Factor for Neuromuscular Transmission: Effects of Dimethylsulphoxide, Cannabinoids and Synaptic Homeostasis. J Neuromuscul Dis 2021; 8:831-844. [PMID: 34334412 DOI: 10.3233/jnd-210654] [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: 11/15/2022]
Abstract
BackgroundIn myasthenia gravis, impaired postsynaptic sensitivity to acetylcholine results in failure of neuromuscular transmission and fatiguing muscle weakness.ObjectiveDevelop an ex vivo muscle contraction assay to test cannabinoids and other substances that might act on the myasthenic neuromuscular junction to restore control of the muscle.MethodsTubocurarine was added to an ex vivo, mouse phrenic nerve-hemidiaphragm muscle preparation to reduce acetylcholine sensitivity. This produced a myasthenia-like decrement in twitch force during a train of 10 nerve impulses (3 / sec). Endplate potential (EPP) recordings were used to confirm and extend the findings.ResultsSurprisingly, addition to the bath of dimethylsulphoxide (DMSO), at concentrations as low as 0.1%(v/v), partially reversed the decrement in nerve-evoked force. Intracellular electrophysiology, conducted in the presence of tubocurarine, showed that DMSO increased the amplitudes of both the spontaneous miniature EPP (MEPP) and the (nerve-evoked) EPP. In the absence of tubocurarine (synaptic potentials at physiological levels), an adaptive fall in quantal content negated the DMSO-induced rise in EPP amplitude. The effects of cannabinoid receptor agonists (solubilized with DMSO) in the contraction assay do not support their further exploration as useful therapeutic agents for myasthenia gravis. CP 55,940 (a dual agonist for cannabinoid receptor types 1 and 2) reversed the beneficial effects of DMSO.Conclusions:We demonstrate a powerful effect of DMSO upon quantal amplitude that might mislead pharmacological studies of synaptic function wherever DMSO is used as a drug vehicle. Our results also show that compounds targeting impaired neuromuscular transmission should be tested under myasthenic-like conditions, so as to avoid confounding effects of synaptic homeostasis.
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Affiliation(s)
- Gianmaria Lorenzo Odierna
- Discipline of Physiology and Bosch Institute, The University of Sydney, NSW, Australia.,Queensland Brain Institute, The University of Queensland, St Lucia, Queensland, Australia
| | - William Donald Phillips
- Discipline of Physiology and Bosch Institute, The University of Sydney, NSW, Australia.,School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
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Abudalou M, Malkowski M, Robles MR, Vega EA, Slama MCC. A Rare Presentation of a Rare Disease: Oropharyngeal Dysphagia as The Main Manifestation of Myasthenia Gravis. Cureus 2021; 13:e16880. [PMID: 34513455 PMCID: PMC8411993 DOI: 10.7759/cureus.16880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2021] [Indexed: 12/02/2022] Open
Abstract
Oropharyngeal dysphagia is defined as the inability or difficulty to initiate swallowing. It has a wide array of etiologies including structural and neurologic diseases. Myasthenia gravis (MG) is a rare autoimmune condition caused by antibodies against the post-synaptic membranes of the neuromuscular junction, leading to fatigable weakness of skeletal muscles. Bulbar symptoms are less prevalent than ocular symptoms or limb weakness but can be particularly morbid. Non-neurologists are more likely to be the first providers to evaluate patients with dysphagia and should be familiar with MG. We report a unique case of newly diagnosed MG with the initial presentation of solid food and liquid dysphagia.
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Affiliation(s)
- Mohammad Abudalou
- Internal Medicine, St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, USA
| | - Michael Malkowski
- Internal Medicine, St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, USA
| | - Marcel R Robles
- Internal Medicine, St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, USA
| | - Eduardo A Vega
- Surgery, St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, USA
| | - Michael C C Slama
- Neurology, St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, USA
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Ling J, Micieli A, Micieli JA. A Man Who Cannot Elevate His Right Eye or Abduct His Left Eye. JAMA Ophthalmol 2021; 139:1139-1140. [PMID: 34292301 DOI: 10.1001/jamaophthalmol.2021.0028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Jennifer Ling
- Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew Micieli
- Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan A Micieli
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada.,Kensington Vision and Research Centre, Toronto, Ontario, Canada.,Department of Ophthalmology, St Michael's Hospital, Toronto, Ontario, Canada
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Fc-Receptor Targeted Therapies for the Treatment of Myasthenia gravis. Int J Mol Sci 2021; 22:ijms22115755. [PMID: 34071155 PMCID: PMC8198115 DOI: 10.3390/ijms22115755] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/16/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease in which immunoglobulin G (IgG) antibodies (Abs) bind to acetylcholine receptors (AChR) or to functionally related molecules in the postsynaptic membrane at the neuromuscular junction. IgG crystallizable fragment (Fc)-mediated effector functions, such as antibody-dependent complement deposition, contribute to disease development and progression. Despite progress in understanding Ab-mediated disease mechanisms, immunotherapy of MG remained rather unspecific with corticosteroids and maintenance with immunosuppressants as first choice drugs for most patients. More specific therapeutic IgG Fc-based platforms that reduce serum half-life or effector functions of pathogenic MG-related Abs are currently being developed, tested in clinical trials or have recently been successfully translated into the clinic. In this review, we illustrate mechanisms of action and clinical efficacies of emerging Fc-mediated therapeutics such as neonatal Fc receptor (FcRn)-targeting agents. Furthermore, we evaluate prospects of therapies targeting classical Fc receptors that have shown promising therapeutic efficacy in other antibody-mediated conditions. Increased availability of Fc- and Fc receptor-targeting biologics might foster the development of personalized immunotherapies with the potential to induce sustained disease remission in patients with MG.
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Abstract
Introduction: Myasthenia gravis (MG) is an antibody-mediated disease with diverse serology and clinical presentation. Currently, MG is managed by untargeted immunomodulatory agents. About 15% patients are refractory to these therapies. Several novel and targeted treatments are on the horizon. Rituximab, a monoclonal antibody, is reported to be highly effective with widespread oof-label usage in MG, particularly in patients with antibody against muscle-specific kinase or refractory disease. However, a recent trial showed negative results. Compared to conventional oral immunosuppressive therapies used in MG, Rituximab has several benefits. Regular hematological monitoring is not required though serious side effects can occur. Current status of Rituximab in MG and newer immunosuppressants is discussed.Areas explored: Biologic features, clinical effectiveness, safety profile, and newer preparations of Rituximab.Expert opinion: Rituximab provides a promising option for management of MG, particularly in patients with muscle-specific kinase antibodies or those with refractory disease. Several knowledge gaps remain due to scarcity of data from randomized controlled studies. Despite lack of regulatory approval Rituximab has found widespread usage in MG. Large, well-designed studies are needed to assess the comparative efficacy of Rituximab and its optimal regimen in MG.
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Affiliation(s)
- Zaeem A Siddiqi
- Division of Neurology, Dept of Medicine, University of Alberta Hospital, Edmonton, Canada
| | - Wasim Khan
- Division of Neurology, Dept of Medicine, University of Alberta Hospital, Edmonton, Canada
| | - Faraz S Hussain
- Division of Neurology, Dept of Medicine, University of Alberta Hospital, Edmonton, Canada
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Barrantes FJ. Possible implications of dysregulated nicotinic acetylcholine receptor diffusion and nanocluster formation in myasthenia gravis. Neural Regen Res 2021; 16:242-246. [PMID: 32859770 PMCID: PMC7896218 DOI: 10.4103/1673-5374.290880] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Myasthenia gravis is a rare and invalidating disease affecting the neuromuscular junction of voluntary muscles. The classical form of this autoimmune disease is characterized by the presence of antibodies against the most abundant protein in the neuromuscular junction, the nicotinic acetylcholine receptor. Other variants of the disease involve autoimmune attack of non-receptor scaffolding proteins or enzymes essential for building or maintaining the integrity of this peripheral synapse. This review summarizes the participation of the above proteins in building the neuromuscular junction and the destruction of this cholinergic synapse by autoimmune aggression in myasthenia gravis. The review also covers the application of a powerful biophysical technique, superresolution optical microscopy, to image the nicotinic receptor in live cells and follow its motional dynamics. The hypothesis is entertained that anomalous nanocluster formation by antibody crosslinking may lead to accelerated endocytic internalization and elevated turnover of the receptor, as observed in myasthenia gravis.
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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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Threetong T, Poonyathalang A, Preechawat P, Jindahra P, Padungkiatsagul T, Vanikieti K. Initial Treatment Response in Ocular Myasthenia Gravis: A Comparison Between Low and Moderate Doses of Prednisolone. Clin Ophthalmol 2020; 14:2051-2056. [PMID: 32801613 PMCID: PMC7383101 DOI: 10.2147/opth.s261259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 06/23/2020] [Indexed: 11/23/2022] Open
Abstract
Purpose To evaluate the initial treatment response to low doses of prednisolone, compared with moderate doses, in ocular myasthenia gravis (OMG). Patients and Methods A retrospective chart review of patients with adult-onset (age ≥15 years old) OMG, who were treated with prednisolone, was conducted. Subjects were divided into two groups according to their prednisolone dosing regimen. The low-dose group was defined as those with an average 12-week cumulative dose of prednisolone <0.435 mg/kg/day and the moderate-dose group averaged 0.435–1.000 mg/kg/day. The primary outcome of interest was the comparison of clinical response to prednisolone at 12 weeks between the low-dose and moderate-dose groups. The secondary outcome was the difference in adverse events between treatment groups. Results Of 34 subjects, 16 subjects (47.1%) were male. The mean age at onset was 44.0±18.1 years. The most common presenting ocular feature was ptosis with ophthalmoplegia (22 subjects, 64.7%), followed by isolated ptosis (nine subjects, 26.5%) and isolated ophthalmoplegia (three subjects, 8.8%). Half of the subjects were treated with low-dose prednisolone and the other half were treated with moderate-dose prednisolone. There were no substantial differences in baseline characteristics between treatment groups. After 12 weeks of treatment, nine of 17 subjects (52.9%) and 13 of 17 subjects (76.5%) in the low- and moderate-dose groups, respectively, were regarded as responsive to the prednisolone treatment (P=0.28). Adverse events were exclusively observed in the moderate-dose group. Conclusion Treatment of OMG with an average 12-week cumulative dose of prednisolone <0.435 mg/kg/day (low dose) shows a comparable responsive outcome to 0.435–1.000 mg/kg/day of prednisolone (moderate dose). Treating OMG with low-dose prednisolone can minimize prednisolone-related adverse events. However, a prospective randomized controlled trial with a larger study population is warranted in order to gain more insight into the proper dosage of prednisolone for OMG.
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Affiliation(s)
- Thanatporn Threetong
- Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.,Department of Ophthalmology, Faculty of Medicine, Burapha University, Chonburi, Thailand
| | - Anuchit Poonyathalang
- Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Pisit Preechawat
- Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Panitha Jindahra
- Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Tanyatuth Padungkiatsagul
- Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Kavin Vanikieti
- Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
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Ojeda J, Bermedo-García F, Pérez V, Mella J, Hanna P, Herzberg D, Tejero R, López-Manzaneda M, Tabares L, Henríquez JP. The Mouse Levator Auris Longus Muscle: An Amenable Model System to Study the Role of Postsynaptic Proteins to the Maintenance and Regeneration of the Neuromuscular Synapse. Front Cell Neurosci 2020; 14:225. [PMID: 32848618 PMCID: PMC7405910 DOI: 10.3389/fncel.2020.00225] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 06/26/2020] [Indexed: 12/16/2022] Open
Abstract
The neuromuscular junction (NMJ) is the peripheral synapse that controls the coordinated movement of many organisms. The NMJ is also an archetypical model to study synaptic morphology and function. As the NMJ is the primary target of neuromuscular diseases and traumatic injuries, the establishment of suitable models to study the contribution of specific postsynaptic muscle-derived proteins on NMJ maintenance and regeneration is a permanent need. Considering the unique experimental advantages of the levator auris longus (LAL) muscle, here we present a method allowing for efficient electroporation-mediated gene transfer and subsequent detailed studies of the morphology and function of the NMJ and muscle fibers. Also, we have standardized efficient facial nerve injury protocols to analyze LAL muscle NMJ degeneration and regeneration. Our results show that the expression of a control fluorescent protein does not alter either the muscle structural organization, the apposition of the pre- and post-synaptic domains, or the functional neurotransmission parameters of the LAL muscle NMJs; in turn, the overexpression of MuSK, a major regulator of postsynaptic assembly, induces the formation of ectopic acetylcholine receptor clusters. Our NMJ denervation experiments showed complete reinnervation of LAL muscle NMJs four weeks after facial nerve injury. Together, these experimental strategies in the LAL muscle constitute effective methods to combine protein expression with accurate analyses at the levels of structure, function, and regeneration of the NMJ.
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Affiliation(s)
- Jorge Ojeda
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile.,Department of Medical Physiology and Biophysics, School of Medicine, Universidad de Sevilla, Sevilla, Spain.,Developmental Neurobiology Unit, Biomedical Sciences Research Laboratory, Basic Sciences Department, Faculty of Medicine, Universidad Católica de la Santísima Concepción, Concepción, Chile
| | - Francisca Bermedo-García
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
| | - Viviana Pérez
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
| | - Jessica Mella
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
| | - Patricia Hanna
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
| | - Daniel Herzberg
- Veterinary Sciences Clinic, Universidad de Concepción, Concepción, Chile
| | - Rocío Tejero
- Department of Medical Physiology and Biophysics, School of Medicine, Universidad de Sevilla, Sevilla, Spain
| | - Mario López-Manzaneda
- Department of Medical Physiology and Biophysics, School of Medicine, Universidad de Sevilla, Sevilla, Spain
| | - Lucia Tabares
- Department of Medical Physiology and Biophysics, School of Medicine, Universidad de Sevilla, Sevilla, Spain
| | - Juan Pablo Henríquez
- Neuromuscular Studies Laboratory (NeSt Lab), Department of Cell Biology, Faculty of Biological Sciences, Center for Advanced Microscopy (CMA BioBio), Universidad de Concepción, Concepción, Chile
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Takamori M. Myasthenia Gravis: From the Viewpoint of Pathogenicity Focusing on Acetylcholine Receptor Clustering, Trans-Synaptic Homeostasis and Synaptic Stability. Front Mol Neurosci 2020; 13:86. [PMID: 32547365 PMCID: PMC7272578 DOI: 10.3389/fnmol.2020.00086] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/28/2020] [Indexed: 12/18/2022] Open
Abstract
Myasthenia gravis (MG) is a disease of the postsynaptic neuromuscular junction (NMJ) where nicotinic acetylcholine (ACh) receptors (AChRs) are targeted by autoantibodies. Search for other pathogenic antigens has detected the antibodies against muscle-specific tyrosine kinase (MuSK) and low-density lipoprotein-related protein 4 (Lrp4), both causing pre- and post-synaptic impairments. Agrin is also suspected as a fourth pathogen. In a complex NMJ organization centering on MuSK: (1) the Wnt non-canonical pathway through the Wnt-Lrp4-MuSK cysteine-rich domain (CRD)-Dishevelled (Dvl, scaffold protein) signaling acts to form AChR prepatterning with axonal guidance; (2) the neural agrin-Lrp4-MuSK (Ig1/2 domains) signaling acts to form rapsyn-anchored AChR clusters at the innervated stage of muscle; (3) adaptor protein Dok-7 acts on MuSK activation for AChR clustering from “inside” and also on cytoskeleton to stabilize AChR clusters by the downstream effector Sorbs1/2; (4) the trans-synaptic retrograde signaling contributes to the presynaptic organization via: (i) Wnt-MuSK CRD-Dvl-β catenin-Slit 2 pathway; (ii) Lrp4; and (iii) laminins. The presynaptic Ca2+ homeostasis conditioning ACh release is modified by autoreceptors such as M1-type muscarinic AChR and A2A adenosine receptors. The post-synaptic structure is stabilized by: (i) laminin-network including the muscle-derived agrin; (ii) the extracellular matrix proteins (including collagen Q/perlecan and biglycan which link to MuSK Ig1 domain and CRD); and (iii) the dystrophin-associated glycoprotein complex. The study on MuSK ectodomains (Ig1/2 domains and CRD) recognized by antibodies suggested that the MuSK antibodies were pathologically heterogeneous due to their binding to multiple functional domains. Focussing one of the matrix proteins, biglycan which functions in the manner similar to collagen Q, our antibody assay showed the negative result in MG patients. However, the synaptic stability may be impaired by antibodies against MuSK ectodomains because of the linkage of biglycan with MuSK Ig1 domain and CRD. The pathogenic diversity of MG is discussed based on NMJ signaling molecules.
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A Case of Triple-Negative Myasthenia Gravis Lambert-Eaton Overlap Syndrome With Negative Agrin and LRP-4 Antibodies. J Clin Neuromuscul Dis 2020; 21:103-106. [PMID: 31743253 DOI: 10.1097/cnd.0000000000000189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A case of triple-negative myasthenia gravis Lambert-Eaton overlap syndrome with negative Agrin and LRP-4 antibodies. Myasthenia gravis (MG) is an autoimmune disorder that shares similar features with Lambert-Eaton myasthenic syndrome. The combined clinical and electrophysiological findings of MG and Lambert-Eaton myasthenic syndrome have been reported, these cases represent the so-called "myasthenia gravis Lambert-Eaton overlap syndrome" (MLOS). A total of 55 MLOS cases have been identified, 13 cases were reported before the acetylcholine receptor (AChR) antibody (ab) testing era, 14 during the AChR-ab era, 26 during the voltage-gated calcium channel (VGCC)-ab era, and 2 cases have been reported during the muscle-specific kinase (MuSK)-ab era, of these; only 1 patient tested negative for all 3 antibodies. New immunological markers have been identified in the study of MG [Agrin and the low-density lipopro-tein receptor-related protein 4 (LRP-4)]. We present a patient with MLOS who tested negative for all 5 (AChR, MuSK, VGCC, Agrin, and LRP-4) serologic markers.
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Gokuladhas S, Schierding W, Cameron-Smith D, Wake M, Scotter EL, O’Sullivan J. Shared Regulatory Pathways Reveal Novel Genetic Correlations Between Grip Strength and Neuromuscular Disorders. Front Genet 2020; 11:393. [PMID: 32391060 PMCID: PMC7194178 DOI: 10.3389/fgene.2020.00393] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
Muscle weakness is a common consequence of both aging (sarcopenia) and neuromuscular disorders (NMD). Whilst genome-wide association (GWA) studies have identified genetic variants associated with grip strength (GS; measure of muscle strength/weakness) and NMDs, including multiple sclerosis (MS), myasthenia gravis (MG) and amyotrophic lateral sclerosis (ALS), it is not known whether there are common mechanisms between these phenotypes. To examine this, we have integrated GS and NMD associated genetic variants (single nucleotide polymorphisms; SNPs) in a multimorbid analysis that leverages high-throughput chromatin interaction (Hi-C) data and expression quantitative trait loci data to identify target genes (i.e., SNP-mediated gene regulation). Biological pathways enriched by these genes were then identified using next-generation pathway enrichment analysis. Lastly, druggable genes were identified using drug gene interaction (DGI) database. We identified gene regulatory mechanisms associated with GS, MG, MS, and ALS. The SNPs associated with GS regulate a subset of genes that are also regulated by the SNPs of MS, MG, and ALS. Yet, we did not find any genes commonly regulated by all four phenotype associated SNPs. By contrast, we identified significant enrichment in three pathways (mTOR signaling, axon guidance, and alcoholism) that are commonly affected by the gene regulatory mechanisms associated with all four phenotypes. 13% of the genes we identified were known drug targets, and GS shares at least one druggable gene and pathway with each of the NMD phenotypes. We have identified significant biological overlaps between GS and NMD, demonstrating the potential for spatial genetic analysis to identify common mechanisms between potential multimorbid phenotypes. Collectively, our results form the foundation for a shift from a gene to a pathway-based approach to the rationale design of therapeutic interventions and treatments for NMD.
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Affiliation(s)
| | | | - David Cameron-Smith
- Liggins Institute, The University of Auckland, Auckland, New Zealand
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Melissa Wake
- Murdoch Children’s Research Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Emma L. Scotter
- Department of Pharmacology and Clinical Pharmacology, The University of Auckland, Auckland, New Zealand
- Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Justin O’Sullivan
- Liggins Institute, The University of Auckland, Auckland, New Zealand
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Visualization of autoantibodies and neutrophils in vivo identifies novel checkpoints in autoantibody-induced tissue injury. Sci Rep 2020; 10:4509. [PMID: 32161277 PMCID: PMC7066238 DOI: 10.1038/s41598-020-60233-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 11/21/2019] [Indexed: 12/29/2022] Open
Abstract
In several autoimmune diseases, e.g., pemphigoid disease (PD), autoantibodies are the direct cause of pathology. Albeit key requirements for antibody-mediated diseases were identified, their interactions and exact temporal and spatial interactions remained elusive. The skin is easily accessible for imaging. Thus, we selected epidermolysis bullosa acquisita (EBA), a PD with autoantibodies to type VII collagen (COL7), to visualize interactions of autoantibodies, target tissue and effector cells (neutrophils). Following injection into mice, anti-COL7 IgG bound to the dermal-epidermal junction (DEJ) within minutes. We unexpectedly observed an inhomogeneous distribution of autoantibodies along the DEJ. Thus, we hypothesized that specific external triggers may affect autoantibody distribution. Indeed, mechanical irritation led to an increased autoantibody binding along the DEJ. Subsequently, anti-COL7 IgG was injected into mice expressing green fluorescent protein under the LysM promoter (LysM-eGFP) mice. This allows to visualize myeloid cells in vivo in these animals. Using multiphoton imaging, we observed a limited extravasation of LysM-eGFP+ cells into skin was observed within 24 hours. Intriguingly, LysM-eGFP+ cells did not immediately co-localize with autoantibodies, which was only noted at later time points. Of note, interactions of LysM-eGFP+ with the autoantibodies at the DEJ were short-lived. Collectively, our results define the following checkpoints for autoantibody-induced tissue injury: (i) autoantibody egress to target tissue influenced by mechanical trigger factors, (ii) neutrophil recruitment into the vicinity of autoantibody deposits and (iii) short-term neutrophil localization to these deposits, as well as (iv) delayed recruitment of neutrophils with subsequent autoantibody-induced inflammation.
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Lazaridis K, Tzartos SJ. Autoantibody Specificities in Myasthenia Gravis; Implications for Improved Diagnostics and Therapeutics. Front Immunol 2020; 11:212. [PMID: 32117321 PMCID: PMC7033452 DOI: 10.3389/fimmu.2020.00212] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 01/27/2020] [Indexed: 12/13/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease characterized by muscle weakness and fatiguability of skeletal muscles. It is an antibody-mediated disease, caused by autoantibodies targeting neuromuscular junction proteins. In the majority of patients (~85%) antibodies against the muscle acetylcholine receptor (AChR) are detected, while in 6% antibodies against the muscle-specific kinase (MuSK) are detected. In ~10% of MG patients no autoantibodies can be found with the classical diagnostics for AChR and MuSK antibodies (seronegative MG, SN-MG), making the improvement of methods for the detection of known autoantibodies or the discovery of novel antigenic targets imperative. Over the past years, using cell-based assays or improved highly sensitive immunoprecipitation assays, it has been possible to detect autoantibodies in previously SN-MG patients, including the identification of the low-density lipoprotein receptor-related protein 4 (LRP4) as a third MG autoantigen, as well as AChR and MuSK antibodies undetectable by conventional methods. Furthermore, antibodies against other extracellular or intracellular targets, such as titin, the ryanodine receptor, agrin, collagen Q, Kv1.4 potassium channels and cortactin have been found in some MG patients, which can be useful biomarkers. In addition to the improvement of diagnosis, the identification of the patients' autoantibody specificity is important for their stratification into respective subgroups, which can differ in terms of clinical manifestations, prognosis and most importantly their response to therapies. The knowledge of the autoantibody profile of MG patients would allow for a therapeutic strategy tailored to their MG subgroup. This is becoming especially relevant as there is increasing progress toward the development of antigen-specific therapies, targeting only the specific autoantibodies or immune cells involved in the autoimmune response, such as antigen-specific immunoadsorption, which have shown promising results. We will herein review the advances made by us and others toward development of more sensitive detection methods and the identification of new antibody targets in MG, and discuss their significance in MG diagnosis and therapy. Overall, the development of novel autoantibody assays is aiding in the more accurate diagnosis and classification of MG patients, supporting the development of advanced therapeutics and ultimately the improvement of disease management and patient quality of life.
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Affiliation(s)
| | - Socrates J Tzartos
- Department of Neurobiology, Hellenic Pasteur Institute, Athens, Greece.,Tzartos NeuroDiagnostics, Athens, Greece
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Litchman T, Roy B, Kumar A, Sharma A, Njike V, Nowak RJ. Differential response to rituximab in anti-AChR and anti-MuSK positive myasthenia gravis patients: a single-center retrospective study. J Neurol Sci 2020; 411:116690. [PMID: 32028072 DOI: 10.1016/j.jns.2020.116690] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/20/2019] [Accepted: 01/17/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND B-cell targeted therapy with rituximab has shown durable response in treating refractory myasthenia gravis (MG). This study compares the response to rituximab between patients with acetylcholine receptor autoantibody positive (AChR+) and muscle-specific kinase autoantibody positive (MuSK+) MG. METHODS This retrospective study included 33 patients with either AChR+ or MuSK+ MG who were treated with rituximab from 05/31/2003 to 05/31/2017. Pretreatment and post-treatment immunotherapy regimens, clinical symptoms, and examination findings were evaluated. RESULTS Median MGFA Class of II at baseline improved to an asymptomatic median classification at 12-months and last follow-up (p-values <.001) post-rituximab. Improvement in MGFA class was not significantly different between the groups. Twenty-one patients achieved clinical remission (12/17 AChR+, 9/16 MuSK+) with time to remission of 441.4 ± 336.6 days for AChR+ versus 230 ± 180.8 days for MuSK+ patients (p-value 0.049). The mean prednisone dosage requirement decreased significantly in both groups post-rituximab. AChR+ patients required more hospitalizations for exacerbation post-rituximab (p-value 0.046). CONCLUSION Rituximab treatment response is observed in both AChR+ and MuSK+ patients supporting the role of B cell depletion in the management of MG. While there was no significant difference between these groups in terms of clinical improvement, symptom-free state, and prednisone burden, MuSK+ MG patients may experience greater benefits, including earlier time to remission, fewer exacerbations and hospitalizations post-treatment.
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Affiliation(s)
- Tess Litchman
- Yale School of Medicine, Department of Neurology, New Haven, CT, USA
| | - Bhaskar Roy
- Yale School of Medicine, Department of Neurology, New Haven, CT, USA
| | - Aditya Kumar
- Yale School of Medicine, Department of Neurology, New Haven, CT, USA
| | - Aditi Sharma
- Yale School of Medicine, Department of Neurology, New Haven, CT, USA
| | - Valentine Njike
- Griffin Hospital-Derby, Yale University Prevention Research Center, Derby, CT, USA
| | - Richard J Nowak
- Yale School of Medicine, Department of Neurology, New Haven, CT, USA.
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Zhang Y, Yang J, Chen Y, Lv J, Zhang J, Zhang Y, Zhao X, Fang H, Liu C, Zhang Q, Cui X, Wang X, Gao F. iTRAQ-Based Proteomics Analysis of Plasma of Myasthenia Gravis Patients Treated with Jia Wei Bu Zhong Yi Qi Decoction. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2019; 2019:9147072. [PMID: 31915455 PMCID: PMC6930785 DOI: 10.1155/2019/9147072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 09/04/2019] [Accepted: 10/01/2019] [Indexed: 11/18/2022]
Abstract
Myasthenia gravis (MG) is an autoimmune disease. A proportion of MG patients did not get satisfactory results after treatment with pyridostigmine and prednisone. Jia Wei Bu Zhong Yi Qi (Jia Wei BZYQ) decoction, a water extract from multiple herbs, has been demonstrated to be effective in the treatment of multiple "Qi deficiency type" diseases including MG in China. In this text, we investigated protein alterations in the plasma from healthy volunteers (C), MG patients without any treatment (T1), MG patients with routine western medical treatment (T2), and MG patients with combined treatments of Jia Wei BZYQ decoction and routine western medicines (T3) and identified some potential proteins involved in the pathogenesis and treatment of MG. iTRAQ (isobaric tags for relative and absolute quantitation) and 2D-LC-MS/MS (two-dimensional liquid chromatography-tandem mass spectrometry technologies) were employed to screen differentially expressed proteins. The identification, quantification, functional annotation, and interaction of proteins were analyzed by matching software and databases. In our project, 618 proteins were identified, among which 447 proteins had quantitative data. The number of differentially expressed proteins was 110, 117, 143, 115, 86, and 158 in T1 vs. C, T2 vs. C, T2 vs. T1, T3 vs. C, T3 vs. T1, and T3 vs. T2 groups, respectively. Functional annotation results showed that many differentially expressed proteins were closely associated with immune responses. For instance, some key proteins such as C-reactive protein, apolipoprotein C-III, apolipoprotein A-II, alpha-actinin-1, and thrombospondin-1 have been found to be abnormally expressed in T3 group compared to T1 group or T2 group. Interaction network analyses also provided some potential biomarkers or targets for MG management.
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Affiliation(s)
- Yunke Zhang
- School of Rehabilitation Medicine, Henan University of Chinese Medicine, No. 156 Jinshui East Road, Zhengzhou City, Henan Province 450008, China
| | - Junhong Yang
- Department of Neurology, The First Affiliated Hospital of Henan University of Chinese Medicine, No. 19, Renmin Road, Zhengzhou City, Henan Province 450000, China
| | - Yingzhe Chen
- Department of Neurology, Pingdingshan Traditional Chinese Medicine Hospital, Henan No. 4 Courtyard, North Section of Zhongxing Road, Pingdingshan City 467000, China
| | - Jie Lv
- Department of Neuroimmunology Research, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Henan, No. 40, University Road, Zhengzhou City, Henan Province 450052, China
| | - Jing Zhang
- Department of Neuroimmunology Research, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Henan, No. 40, University Road, Zhengzhou City, Henan Province 450052, China
| | - Yingna Zhang
- Department of Neuroimmunology Research, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Henan, No. 40, University Road, Zhengzhou City, Henan Province 450052, China
| | - Xue Zhao
- Department of Neuroimmunology Research, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Henan, No. 40, University Road, Zhengzhou City, Henan Province 450052, China
| | - Hua Fang
- Department of Neuroimmunology Research, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Henan, No. 40, University Road, Zhengzhou City, Henan Province 450052, China
| | - Chongchong Liu
- Beijing University of Chinese Medicine, No. 11, North Third Ring Road, Chaoyang District, Beijing 100029, China
| | - Qingyong Zhang
- Myasthenia Gravis Comprehensive Diagnosis and Treatment Center, Henan Provincial People's Hospital, No. 7, Weiwu Road, Zhengzhou City, Henan Province 450003, China
| | - Xinzheng Cui
- Myasthenia Gravis Comprehensive Diagnosis and Treatment Center, Henan Provincial People's Hospital, No. 7, Weiwu Road, Zhengzhou City, Henan Province 450003, China
| | - Xiaohan Wang
- Henan University of Chinese Medicine, No. 156 Jinshui East Road, Zhengzhou City, Henan Province 450008, China
| | - Feng Gao
- Department of Neuroimmunology Research, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Henan, No. 40, University Road, Zhengzhou City, Henan Province 450052, China
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Swenarchuk LE. Nerve, Muscle, and Synaptogenesis. Cells 2019; 8:cells8111448. [PMID: 31744142 PMCID: PMC6912269 DOI: 10.3390/cells8111448] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/06/2019] [Accepted: 11/06/2019] [Indexed: 12/21/2022] Open
Abstract
The vertebrate skeletal neuromuscular junction (NMJ) has long served as a model system for studying synapse structure, function, and development. Over the last several decades, a neuron-specific isoform of agrin, a heparan sulfate proteoglycan, has been identified as playing a central role in synapse formation at all vertebrate skeletal neuromuscular synapses. While agrin was initially postulated to be the inductive molecule that initiates synaptogenesis, this model has been modified in response to work showing that postsynaptic differentiation can develop in the absence of innervation, and that synapses can form in transgenic mice in which the agrin gene is ablated. In place of a unitary mechanism for neuromuscular synapse formation, studies in both mice and zebrafish have led to the proposal that two mechanisms mediate synaptogenesis, with some synapses being induced by nerve contact while others involve the incorporation of prepatterned postsynaptic structures. Moreover, the current model also proposes that agrin can serve two functions, to induce synaptogenesis and to stabilize new synapses, once these are formed. This review examines the evidence for these propositions, and concludes that it remains possible that a single molecular mechanism mediates synaptogenesis at all NMJs, and that agrin acts as a stabilizer, while its role as inducer is open to question. Moreover, if agrin does not act to initiate synaptogenesis, it follows that as yet uncharacterized molecular interactions are required to play this essential inductive role. Several alternatives to agrin for this function are suggested, including focal pericellular proteolysis and integrin signaling, but all require experimental validation.
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Geng G, Yu X, Jiang J, Yu X. Aetiology and pathogenesis of paraneoplastic autoimmune disorders. Autoimmun Rev 2019; 19:102422. [PMID: 31733369 DOI: 10.1016/j.autrev.2019.102422] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 06/21/2019] [Indexed: 12/15/2022]
Abstract
Paraneoplastic autoimmune disorders (PAD) represent a group of autoimmune diseases associated with neoplasms. As a consequence of a remote autoimmunity-mediated effect, PAD are found in multiple organs or tissues, including the skin, blood and nervous system. Compared with non-paraneoplastic autoimmune diseases, PAD have different aetiologies, pathologies, disease symptoms and treatment responses. There are two main origins of autoimmunity in PAD: neoplasm-mediated dysregulated homeostasis in immune cells/organs and in autoantigens. Pathologically, PAD are mediated predominantly by either autoantibodies or autoreactive T-cells. In the past decade, significant progress has been achieved in increasing our understanding of the aetiology and pathology of PAD. In this review article, we aim to provide a comprehensive overview of the recent advances in this field.
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Affiliation(s)
- Guojun Geng
- Department of Thoracic Surgery, the First Affiliated Hospital of Xiamen University, Xiamen 361003, China
| | - Xiuyi Yu
- Department of Thoracic Surgery, the First Affiliated Hospital of Xiamen University, Xiamen 361003, China
| | - Jie Jiang
- Department of Thoracic Surgery, the First Affiliated Hospital of Xiamen University, Xiamen 361003, China.
| | - Xinhua Yu
- Priority Area Asthma & Allergy, Research Center Borstel, 23845, Borstel, Germany.
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Souto EB, Lima B, Campos JR, Martins-Gomes C, Souto SB, Silva AM. Myasthenia gravis: State of the art and new therapeutic strategies. J Neuroimmunol 2019; 337:577080. [PMID: 31670062 DOI: 10.1016/j.jneuroim.2019.577080] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 10/04/2019] [Indexed: 12/11/2022]
Abstract
Myasthenia Gravis (MG) - an autoimmune neuromuscular disease - is known by the production of autoantibodies against components of the neuromuscular junction mainly to the acetylcholine receptor, which cause the destruction and compromises the synaptic transmission. This disease is characterized by fluctuating and fatigable muscle weakness, becoming more intensive with activity, but with an improvement under resting. There are many therapeutic strategies used to alleviate MG symptoms, either by improving the transmission of the nerve impulse or by ameliorating autoimmune reactions with e.g. steroids, immunosuppressant drugs, or monoclonal antibodies (rituximab and eculizumab). Many breakthroughs in the discovery of new therapeutic targets have been reported, but MG remains to be a chronic disease where the symptoms are kept in the majority of patients. In this review, we discuss the different therapeutic strategies that have been used over the years to alleviate MG symptoms, as well as innovative therapeutic approaches currently under study.
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Affiliation(s)
- Eliana B Souto
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra (FFUC), Pólo das Ciências da Saúde, 3000-548 Coimbra, Portugal; CEB - Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
| | - Bernardo Lima
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra (FFUC), Pólo das Ciências da Saúde, 3000-548 Coimbra, Portugal
| | - Joana R Campos
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra (FFUC), Pólo das Ciências da Saúde, 3000-548 Coimbra, Portugal
| | - Carlos Martins-Gomes
- Department of Biology and Environment, School of Life and Environmental Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - Selma B Souto
- Department of Endocrinology of S. João Hospital, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
| | - Amélia M Silva
- Department of Biology and Environment, School of Life and Environmental Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal; Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
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Jing S, Lu J, Song J, Luo S, Zhou L, Quan C, Xi J, Zhao C. Effect of low-dose rituximab treatment on T- and B-cell lymphocyte imbalance in refractory myasthenia gravis. J Neuroimmunol 2019; 332:216-223. [DOI: 10.1016/j.jneuroim.2019.05.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 05/04/2019] [Accepted: 05/04/2019] [Indexed: 01/09/2023]
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48
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Roda RH, Doherty L, Corse AM. Stopping oral steroid-sparing agents at initiation of rituximab in myasthenia gravis. Neuromuscul Disord 2019; 29:554-561. [DOI: 10.1016/j.nmd.2019.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 05/31/2019] [Accepted: 06/03/2019] [Indexed: 11/25/2022]
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Huang K, Luo YB, Yang H. Autoimmune Channelopathies at Neuromuscular Junction. Front Neurol 2019; 10:516. [PMID: 31156543 PMCID: PMC6533877 DOI: 10.3389/fneur.2019.00516] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 04/30/2019] [Indexed: 12/22/2022] Open
Abstract
The neuromuscular junction, also called myoneural junction, is a site of chemical communication between a nerve fiber and a muscle cell. There are many types of channels at neuromuscular junction that play indispensable roles in neuromuscular signal transmission, such as voltage-gated calcium channels and voltage-gated potassium channels on presynaptic membrane, and acetylcholine receptors on post-synaptic membrane. Over the last two decades, our understanding of the role that autoantibodies play in neuromuscular junction disorders has been greatly improved. Antibodies against these channels cause a heterogeneous group of diseases, such as Lambert-Eaton syndrome, Isaacs' syndrome and myasthenia gravis. Lambert-Eaton syndrome is characterized by late onset of fatigue, skeletal muscle weakness, and autonomic symptoms. Patients with Isaacs' syndrome demonstrate muscle cramps and fasciculation. Myasthenia gravis is the most common autoimmune neuromuscular junction channelopathy characterized by fluctuation of muscle weakness. All these disorders have a high risk of tumor. Although these channelopathies share some common features, they differ for clinical features, antibodies profile, neurophysiological features, and treatments. The purpose of this review is to give a comprehensive insight on recent advances in autoimmune channelopathies at the neuromuscular junction.
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Affiliation(s)
- Kun Huang
- Neurology Department, Xiangya Hospital, Central South University, Changsha, China.,Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yue-Bei Luo
- Neurology Department, Xiangya Hospital, Central South University, Changsha, China
| | - Huan Yang
- Neurology Department, Xiangya Hospital, Central South University, Changsha, China
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50
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Çebi M, Durmuş H, Yılmaz V, Yentür SP, Aysal F, Oflazer P, Parman Y, Deymeer F, Saruhan-Direskeneli G. Relation of HLA-DRB1 to IgG4 autoantibody and cytokine production in muscle-specific tyrosine kinase myasthenia gravis (MuSK-MG). Clin Exp Immunol 2019; 197:214-221. [PMID: 30929252 DOI: 10.1111/cei.13302] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2019] [Indexed: 12/12/2022] Open
Abstract
A small subset of myasthenia gravis (MG) patients develop autoantibodies against muscle-specific kinase (MuSK), which are predominantly of the immunoglobulin (Ig)G4 isotype. MuSK-MG is strongly associated with HLA-DRB1*14, HLA-DRB1*16 and HLA-DQB1*05. In this study, the possible effects of these HLA associations on MuSK IgG autoantibody or cytokine production were investigated. Samples from 80 MG patients with MuSK antibodies were studied. The disease-associated HLA types were screened in the DNA samples. The IgG1, IgG2, IgG3 and IgG4 titres of the MuSK antibodies and the levels of interleukin (IL)-4, IL-6, IL-17A and IL-10 were measured in the sera. Comparisons were made among the groups with or without HLA-DRB1*14, HLA-DRB1*16 or HLA-DQB1*05. The IgG4 titres of the MuSK antibodies were higher than those of the IgG1, IgG2 and IgG3 isotypes among the whole group of patients. DRB1*14 (+) DRB1*16 (-) patients had higher levels of IgG4 antibodies than those of DRB1*14 (-) DRB1*16 (+) patients. DRB1*14 (+) DRB1*16 (+) patients also had higher levels of IgG4 antibodies than those of DRB1*14 (-) DRB1*16 (+) and DRB1*14 (-) DRB1*16 (-) patients. Higher IL-10 and lower IL-17A levels were measured in DRB1*14 (+) DRB1*16 (-) patients than in DRB1*14 (-) DRB1*16 (-) patients. The higher IgG4 titres of MuSK autoantibodies in patients carrying HLA-DRB1*14 than those in the other patients suggest a role for HLA in the production of the antibodies. The differences in IL-10 and IL-17A support the role of DRB1 in the etiopathogenesis of this autoimmune response.
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Affiliation(s)
- M Çebi
- Department of Physiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - H Durmuş
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - V Yılmaz
- Department of Physiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - S P Yentür
- Department of Physiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - F Aysal
- Department of Neurology, Bakirkoy Research and Training Hospital for Psychiatric and Neurological Diseases, Istanbul, Turkey.,Department of Neurology, Istanbul Medipol University School of Medicine, Istanbul, Turkey
| | - P Oflazer
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Y Parman
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - F Deymeer
- Department of Neurology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - G Saruhan-Direskeneli
- Department of Physiology, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
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