Myasthenia gravis: a clinical-immunological update

[Treatment and clinical course of autoimmune myasthenia in Burkina Faso]

Introduction

In sub-Saharan Africa, autoimmune myasthenia gravis (AMG) is still poorly known and underdiagnosed (delayed diagnosis, poor availability and accessibility of proven effective diagnostic and therapeutic tools), resulting in a poor functional prognosis and high mortality. The aim of the present study was to evaluate the therapeutic and clinical course of AMG in Burkina Faso.

Patients and Methods

This was a longitudinal, multicenter study conducted from March 2015 to April 2023. It included patients with clinical signs suggestive of myasthenia associated with the presence of serum anti-acetylcholine receptor (anti-RACh) antibodies and/or anti-muscle specific kinase (anti-MuSK) antibodies, and/or with the presence of a decrease >10% on electroneuromyography, and/or with a positive therapeutic test to oral anticholinesterase drugs. Data on treatment modalities and clinical evolution were analyzed using Epi InfoTM 7.2.5.0 software. Bivariate analysis with p-value calculation (<0.05) was used to identify factors associated with adverse clinical outcome.

Results

A total of 40 patients with AMG were included, with a female predominance (60%). The median age of onset was 25 years (IQ=7). The median time to neurological consultation and diagnosis was 21 months (IQ=12) and 22 months (IQ=12), respectively. The disease affected young adults in 85% of cases and was generalized in 35 cases. Anti-RACh and anti-MuSK antibodies were present in 22 and 4 of 33 patients, respectively. Thymic hyperplasia and thymoma were found on chest CT in 22 and 6 of 38 patients, respectively. All patients received symptomatic treatment with oral anticholinesterase agents and 36 patients received background treatment with corticosteroids and/or immunosuppressants (azathioprine). Four of 9 patients received a course of intravenous immunoglobulin (IVIG) or plasma exchange (PE) for myasthenic crises. Thymectomy was performed in 16 of the 40 patients. At the end of a median outpatient follow-up of 53 months (IQ=16), of the 40 patients included in the study, 6 (15%) had died, 14 (35%) were in stable clinical remission, and 17 (43%) had partial clinical improvement.

Conclusion

AMG suffers from delayed diagnosis in Burkina Faso. Almost all patients treated for AMG receive anticholinesterase and corticosteroid therapy alone or in combination with azathioprine. Access to IVIG, PE and thymectomy remains limited. Mortality occurs in nearly one in six patients, and stable clinical remission affects only about one third of patients. To improve the prognosis, we need to make available and accessible diagnostic tools and treatments of proven efficacy, such as thymectomy, immunosuppressants, IVIG and PE.

Myasthenia gravis in 2025: five new things and four hopes for the future

The last 10 years has brought transformative developments in the effective treatment of myasthenia gravis (MG). Beginning with the randomized trial of thymectomy in myasthenia gravis that demonstrated efficacy of thymectomy in nonthymomatous MG, several new treatment approaches have completed successful clinical trials and regulatory launch. These modalities, including B cell depletion, complement inhibition, and blockade of the neonatal Fc receptor, are now in use, offering prospects of sustained remission and neuromuscular protection in what is a long-term disease. In this review, we update our clinico-immunological review of 2016 with these important advances, examine their role in treatment algorithms, and focus attention on key issues of biomarkers for prognostication and the growing cohort of older patients, both those with long-term disease, and late-onset MG ('LOMG'). We close by expressing our four hopes for the next 5-10 years: improvements in laboratory medicine to facilitate rapid diagnosis, effective strategies for neuromuscular protection, more research into and better understanding of pathophysiology and treatment response in older individuals, and the potentially transformative role of therapies aimed at delivering a durable response such as chimeric antigen receptor (CAR) T cells. Our postscript summarizes some emerging themes in the field of serological and online biomarkers, which may develop greater stature in the next epoch.

Dysregulated Long Non-coding RNAs in Myasthenia Gravis- A Mini-Review

Myasthenia gravis (MG) is an acquired autoimmune disease that is mediated by humoral immunity, supplemented by cellular immunity, along with participation of the complement system. The pathogenesis of MG is complex; although autoimmune dysfunction is clearly implicated, the specific mechanism remains unclear. Long non-coding RNAs (lncRNAs) are a class of non-coding RNA molecules with lengths greater than 200 nucleotides, with increasing evidence of their rich biological functions and high-level structure conservation. LncRNAs can directly interact with proteins and microRNAs to regulate the expression of target genes at the transcription and post-transcription levels. In recent years, emerging studies have suggested that lncRNAs play roles in the differentiation of immune cells, secretion of immune factors, and complement production in the human body. This suggests the involvement of lncRNAs in the occurrence and progression of MG through various mechanisms. In addition, the differentially expressed lncRNAs in peripheral biofluid may be used as a biomarker to diagnose MG and evaluate its prognosis. Moreover, with the development of lncRNA expression regulation technology, it is possible to regulate the differentiation of immune cells and influence the immune response by regulating the expression of lncRNAs, which will provide a potential therapeutic option for MG. Here, we review the research progress on the role of lncRNAs in different pathophysiological events contributing to MG, focusing on specific lncRNAs that may largely contribute to the pathophysiology of MG, which could be used as potential diagnostic biomarkers and therapeutic targets.

Impact of SARS-CoV-2 infection on patients with myasthenia gravis: a retrospective study in a Chinese population

Background and purpose

Myasthenia gravis (MG) is characterized by fluctuating muscle weakness due to immune-mediated damage to acetylcholine receptors. Viral infections can exacerbate symptoms of muscle weakness, and the clinical status of patients with MG may influence the outcomes of such infections. Here, we identified factors of symptom exacerbation, severe SARS-CoV-2 infection, and pneumonia in patients with MG who are infected with SARS-CoV-2.

Methods

The clinical characteristics and outcomes of 341 MG patients infected with SARS-CoV-2 across multiple regions in China were determined.

Results

The median age of the patients was 49 years (range: 35-60 years) and the median disease duration was 4 years (range: 2-8 years). Among the patients, 67 (49.0%) were male and 174 (51.0%) were female. Multivariate analysis indicated that thymectomy [OR, 1.654 (95% CI, 1.036-2.643); p = 0.035], severe SARS-CoV-2 infection [OR, 4.275 (95% CI, 2.206-8.286); p < 0.001], and pyridostigmine bromide [OR, 1.955 (95% CI, 1.192-3.206); p = 0.008] were associated with exacerbation of MG symptoms in patients infected with SARS-CoV-2. Age was significantly associated with severe SARS-CoV-2 infection [OR, 1.023 (95% CI, 1.001-1.046); p = 0.008], while patients with cardiac/vascular comorbidities exhibited an increased likelihood of severe SARS-CoV-2 infection [OR, 3.276 (95% CI, 1.027-10.449); p = 0.045]. Likewise, steroid treatment [OR, 6.140 (95% CI, 2.335-16.140); p < 0.001] was associated with a significantly increased likelihood of severe SARS-CoV-2 infection compared with symptomatic treatment. Additionally, gender [OR, 0.323 (95% CI, 0.120-0.868); p = 0.025] and SARS-CoV-2 severity [OR, 6.067 (95% CI, 1.953-18.850); p = 0.002] were associated with the occurrence of pneumonia.

Conclusion

We identified factors that were associated with the exacerbation of MG symptoms in patients infected with SARS-CoV-2, including thymectomy, severe SARS-CoV-2 infection, and the use of pyridostigmine bromide. Due to the retrospective nature of the study, these findings should be interpreted as associations rather than predictive factors. However, the results confirm the established relationships between severe SARS-CoV-2 infection and age, cardiovascular comorbidities, and the use of steroid treatment, suggesting that these factors should be considered when managing MG patients during SARS-CoV-2 infection.

Grilled nux vomica alleviates myasthenia gravis by inhibiting the JAK2/STAT3 signaling pathway: a study in a mice model

BACKGROUND

Grilled Nux Vomica (GNV) is a promising traditional Chinese medicine to treat myasthenia gravis (MG), but its effects and mechanisms need further exploration.

METHODS

Experimental autoimmune MG (EAMG) model was established by muscle-specific kinase (MuSK) induction on C57BL/6 J mice. Mice were treated with GNV and/or ruxolitinib (JAK2 inhibitor) or AG490 (STAT3 inhibitor) for 30 days via gavage after modeling and randomized into 7 groups: control, model, low-dose GNV, middle-dose GNV, high-dose GNV, GNV + ruxolitinib, GNV + AG490. Body weight, muscle strength, clinical score, MuSK level, neuromuscular junction integrity (agrin and acetylcholine receptor [AChR] levels), inflammatory factors (IL-2 and IL-6), and the activation of the JAK2/STAT3 pathway were measured and compared between groups.

RESULTS

GNV significantly improved body weight and muscle strength, as well as reduced clinical scores, MuSK levels, and inflammatory markers (IL-2 and IL-6) levels compared with untreated EAMG mice. GNV also protected the neuromuscular junction and increased agrin and AChR co-expression in a dose-dependent manner. In addition, GNV attenuated the levels of p-JAK2 and p-STAT3, which are aberrantly upregulated in EAMG mice. After co-treatment with ruxolitinib or AG490, the effect of GNV on body weight, muscle strength, clinical score, MuSK level, neuromuscular junction integrity, levels of inflammatory factors, and JAK2/STAT3 pathway was further amplified in EAMG mice.

CONCLUSIONS

GNV improves MG by inhibiting the JAK2/STAT3 pathway, which might be an effective therapeutic strategy for MG.

Identification of Potential Key Genes for the Comorbidity of Myasthenia Gravis With Thymoma by Integrated Bioinformatics Analysis and Machine Learning

Background

Thymoma is a key risk factor for myasthenia gravis (MG). The purpose of our study was to investigate the potential key genes responsible for MG patients with thymoma.

Methods

We obtained MG and thymoma dataset from GEO database. Differentially expressed genes (DEGs) were determined and functional enrichment analyses were conducted by R packages. Weighted gene co-expression network analysis (WGCNA) was used to screen out the crucial module genes related to thymoma. Candidate genes were obtained by integrating DEGs of MG and module genes. Subsequently, we identified several candidate key genes by machine learning for diagnosing MG patients with thymoma. The nomogram and receiver operating characteristics (ROC) curves were applied to assess the diagnostic value of candidate key genes. Finally, we investigated the infiltration of immunocytes and analyzed the relationship among key genes and immune cells.

Results

We obtained 337 DEGs in MG dataset and 2150 DEGs in thymoma dataset. Biological function analyses indicated that DEGs of MG and thymoma were enriched in many common pathways. Black module (containing 207 genes) analyzed by WGCNA was considered as the most correlated with thymoma. Then, 12 candidate genes were identified by intersecting with MG DEGs and thymoma module genes as potential causes of thymoma-associated MG pathogenesis. Furthermore, five candidate key genes (JAM3, MS4A4A, MS4A6A, EGR1, and FOS) were screened out through integrating least absolute shrinkage and selection operator (LASSO) regression and Random forest (RF). The nomogram and ROC curves (area under the curve from 0.833 to 0.929) suggested all five candidate key genes had high diagnostic values. Finally, we found that five key genes and immune cell infiltrations presented varying degrees of correlation.

Conclusions

Our study identified five key potential pathogenic genes that predisposed thymoma to the development of MG, which provided potential diagnostic biomarkers and promising therapeutic targets for MG patients with thymoma.

Descriptive analysis of therapeutic outcomes between thoracoscopic and transsternal thymectomy in myasthenia gravis patients from 2011 to 2021

BACKGROUND

Myasthenia gravis is an autoimmune disease with high prevalence of thymus disorders, in which, thymectomy is considered one of the therapeutic approaches in improving the patients' clinical outcomes. Today, thoracoscopic thymectomy has received significant attention than the classic transsternal approach due to fewer complication. Therefore, this study was designed with the aim of investigating the therapeutic outcomes of thymectomy in patients with myasthenia gravis in the Afzalipour Hospital of Kerman between 2011 and 2021.

METHODS

The current study is a descriptive analytical study on patients with myasthenia gravis who underwent surgical thymectomy within 2011-2021. Demographic and clinical characteristics of patients from the time of operation to three years of follow-up were extracted and recorded from clinical records or by phone calls. Data were analyzed using SPSS software.

RESULTS

The data of 70 patients who underwent surgical thymectomy were analyzed. Thymectomy caused a significant reduction in the severity of the disease according to the Osserman classification (P = 0.001). It also significantly reduced the use of corticosteroids (P = 0.001) and IVIG (P = 0.015) compared to the time before the surgery. Sixty-two patients (88.57%) needed to take less medicine than before surgery. Left VATS was associated with less post-operative severity of the disease (P = 0.023). There were only two deaths during the follow-up period.

CONCLUSION

Overall, the findings of the present study demonstrated that thoracoscopic thymectomy is a useful surgical approach that leads to faster recovery, reducing the severity of the disease, need for medication, and complications in patients with myasthenia gravis, In comparison with the transsternal approach.

FcRn Inhibitor Therapies in Neurologic Diseases

In the last decade, the landscape of treating autoimmune diseases has evolved with the emergence and approval of novel targeted therapies. Several new biological agents offer selective and target-specific immunotherapy and therefore fewer side effects, such as neonatal Fc receptor (FcRn)-targeting therapy. Neonatal Fc receptor-targeted therapies are engineered to selectively target FcRn through various methods, such as Fc fragments or monoclonal anti-FcRn antibodies. These approaches enhance the breakdown of autoantibodies by blocking the immunoglobulin G recycling pathway. This mechanism reduces overall plasma immunoglobulin levels, including the levels of pathogenic autoantibodies, without affecting the other immunoglobulin class immunoglobulin A, immunoglobulin E, immunoglobulin M, and immunoglobulin D levels. Drugs that inhibit FcRn include efgartigimod, rozanolixizumab, batoclimab, and nipocalimab. These medications can be administered either intravenously or subcutaneously. Numerous clinical trials are currently underway to investigate their effectiveness, safety, and tolerability in various neurological conditions, including myasthenia gravis and other neurological disorders such as chronic inflammatory demyelinating polyneuropathy, myositis, neuromyelitis optica, and myelin oligodendrocyte glycoprotein antibody disease. Positive results from clinical trials of efgartigimod and rozanolixizumab led to their approval for the treatment of generalized myasthenia gravis. Additional clinical trials are still ongoing. Neonatal Fc receptor inhibitor agents seem to be well tolerated. Reported adverse events include headache (most commonly observed with efgartigimod and rozanolixizumab), upper respiratory tract infection, urinary tract infection, diarrhea, pyrexia, and nausea. Additionally, some of these agents may cause transient hypoalbuminemia and hypercholesterolemia notably reported with batoclimab and nipocalimab. In this review, we discuss the available clinical data for FcRN inhibitor agents in treating different neurological autoimmune diseases.

A predictive nomogram for short-term outcomes of myasthenia gravis patients treated with low-dose rituximab

BACKGROUND

This study aims to establish and validate a predictive nomogram for the short-term clinical outcomes of myasthenia gravis (MG) patients treated with low-dose rituximab.

METHODS

We retrospectively reviewed 108 patients who received rituximab of 600 mg every 6 months in Huashan Hospital and Tangdu Hospital. Of them, 76 patients from Huashan Hospital were included in the derivation cohort to develop the predictive nomogram, which was externally validated using 32 patients from Tangdu Hospital. The clinical response is defined as a ≥ 3 points decrease in QMG score within 6 months. Both clinical and genetic characteristics were included to screen predictors via multivariate logistic regression. Discrimination and calibration were measured by the area under the receiver operating characteristic curve (AUC-ROC) and Hosmer-Lemeshow test, respectively.

RESULTS

Disease duration (OR = 0.987, p = 0.032), positive anti-muscle-specific tyrosine kinase antibodies (OR = 19.8, p = 0.007), and genotypes in FCGR2A rs1801274 (AG: OR = 0.131, p = 0.024;GG:OR = 0.037, p = 0.010) were independently associated with clinical response of post-rituximab patients. The nomogram identified MG patients with clinical response with an AUC-ROC (95% CI) of 0.875 (0.798-0.952) in the derivation cohort and 0.741(0.501-0.982) in the validation cohort. Hosmer-Lemeshow test showed a good calibration (derivation: Chi-square = 3.181, p = 0.923; validation: Chi-square = 8.098, p = 0.424).

CONCLUSIONS

The nomogram achieved an optimal prediction of short-term outcomes in patients treated with low-dose rituximab.

Association between systemic lupus erythematosus and myasthenia gravis: A population-based National Study

BACKGROUND

Systemic lupus erythematosus (SLE) and myasthenia gravis (MG) are autoimmune diseases. Previous case reports and case series suggest an association may exist between these diseases, as well as an increased risk of SLE after thymectomy for MG. We undertook this study to determine whether SLE and MG were associated in large cohorts.

METHODS

We searched the IBM Watson Health Explorys platform and the Department of Veterans Affairs Million Veteran Program (MVP) database for diagnoses of SLE and MG. In addition, we examined subjects enrolled in the Lupus Family Registry and Repository (LFRR) as well as controls for a diagnosis of MG.

RESULTS

Among 59,780,210 individuals captured in Explorys, there were 25,750 with MG and 65,370 with SLE. 370 subjects had both. Those with MG were >10 times more likely to have SLE than those without MG. Those with both diseases were more likely to be women, African American, and at a younger age than MG subjects without SLE. In addition, the MG patients who underwent thymectomy had an increased risk of SLE compared to MG patients who had not undergone thymectomy (OR 3.11, 95% CI: 2.12 to 4.55). Autoimmune diseases such as pernicious anemia and miscellaneous comorbidities such as chronic kidney disease were significantly more common in MG patients who developed SLE. In the MVP, SLE and MG were also significantly associated. Association of SLE and MG in a large SLE cohort with rigorous SLE classification confirmed the association of SLE with MG at a similar level.

CONCLUSION

While the number of patients with both MG and SLE is small, SLE and MG are strongly associated together in very large databases and a large SLE cohort.

Comparative effectiveness and safety of intravenous methylprednisolone and tacrolimus monotherapy in ocular myasthenia gravis with unsatisfactory prednisone responses: a retrospective study

BACKGROUND

Oral prednisone has been recognized as the first-line therapy for the treatment of ocular myasthenia gravis (OMG). However, its long-term use is complicated by numerous adverse effects and is ineffective for some OMG patients in reaching remission. This study aimed to evaluate the effectiveness and safety of intravenous methylprednisolone (IVMP) and tacrolimus monotherapy for OMG patients with unsatisfactory responses to conventional prednisone therapy.

METHODS

We retrospectively reviewed 57 OMG patients who had not achieved satisfactory improvement after prednisone therapy and thereby received IVMP or tacrolimus monotherapy for at least 6 months. Ocular symptoms were evaluated by the ocular-quantitative MG (QMG) score at each time point. A ≥ 2-point fall in ocular QMG score was defined as the cut-off point to indicate clinical improvement. Logistic regression analysis was performed to identify factors associated with the efficacy of IVMP at discharge. Adverse events were recorded.

RESULTS

Both IVMP and tacrolimus monotherapy demonstrated significant clinical efficacy, with no statistical differences observed at the study endpoint. The proportions of patients who reached the cut-off point for efficacy evaluation were higher in the IVMP group than in the tacrolimus group (1, 3, and 6 months: 51.7% (15/29) vs 12.0% (3/25), p = 0.002; 69.0% (20/29) vs 40.0% (10/25), p = 0.033; 69.0% (20/29) vs 46.4% (13/28), p = 0.085, respectively). Multivariate logistics analysis showed that high ocular QMG scores at baseline indicated favourable responses to IVMP treatment (OR = 1.781; 95% CI 1.066-2.975; p = 0.028). All the adverse events were transient and tolerable.

CONCLUSION

Our findings suggest that both IVMP and tacrolimus monotherapy hold promise as viable treatment options for OMG patients with unsatisfactory responses to oral prednisone. The study supports the safety and effectiveness of both therapies, with IVMP exhibiting faster improvement and favourable efficacy in patients with high ocular QMG scores.

Myasthenia Gravis Treatment: From Old Drugs to Innovative Therapies with a Glimpse into the Future

Myasthenia gravis (MG) is a rare autoimmune disease that causes debilitating muscle weakness due to impaired neuromuscular transmission. Since most (about 80-90%) MG patients present autoantibodies against the acetylcholine receptor, standard medical therapy consists of symptomatic treatment with acetylcholinesterase inhibitors (e.g., pyridostigmine). In addition, considering the autoimmune basis of MG, standard therapy includes immunomodulating agents, such as corticosteroids, azathioprine, cyclosporine A, and cyclophosphamide. New strategies have been proposed for the treatment of MG and include complement blockade (i.e., eculizumab, ravulizumab, and zilucoplan) and neonatal Fc receptor antagonism (i.e., efgartigimod and rozanolixizumab). The aim of this review is to provide a detailed overview of the pre- and post-marketing evidence on the five pharmacological treatments most recently approved for the treatment of MG, by identifying both preclinical and clinical studies registered in clinicaltrials.gov. A description of the molecules currently under evaluation for the treatment of MG is also provided.

Erythroderma combined with deeper dermal dermatophytosis due to Trichophyton rubrum in a patient with myasthenia gravis: first case report and literature review

BACKGROUND

Dermatophytes are the most common causative pathogens of mycoses worldwide and usually cause superficial infections. However, they can enter deep into the dermis lead to invasive dermatophytosis such as deeper dermal dermatophytosis on rare occasions. Erythroderma is a severe dermatological manifestation of various diseases resulting in generalized skin redness, but erythroderma due to fungi infections is barely reported. In this article, we reported the first case of erythroderma combined with deeper dermal dermatophytosis due to Trichophyton rubrum (T. rubrum) in a patient with myasthenia gravis.

CASE PRESENTATION

A 48-year-old man was hospitalized because of erythema with scaling and nodules covering his body for a month. The patient had a history of myasthenia gravis controlled by regularly taking prednisolone for > 10 years and accompanied by onychomycosis and tinea pedis lasting > 8 years. Based on histopathological examinations, fungal cultures, and DNA sequencing results, the patient was finally diagnosed with dermatophyte-induced erythroderma combined with deeper dermal dermatophytosis caused by T. rubrum. After 2 weeks of antifungal treatment, the patient had recovered well.

CONCLUSIONS

This case report shows that immunosuppressed patients with long histories of superficial mycoses tend to have a higher risk of developing invasive dermatophytic infections or disseminated fungal infections. Dermatologists should be alert to this condition and promptly treat the superficial dermatophytosis.

Altered Cardiac Autonomic Regulation in Individuals with Myasthenia Gravis-A Systematic Review and Meta-Analysis

The aim of this systematic review with meta-analysis was to determine differences in cardiovascular autonomic parameters between patients with myasthenia gravis (MG) and healthy controls (HCs). Two reviewers searched four electronic databases, namely PubMed, Web of Science, EMBASE, and SCOPUS, from database inception to 7 July 2023 for studies investigating cardiovascular autonomic parameters in MG vs. HCs. A random-effects meta-analysis was performed to compute Hedges' g ± 95% confidence intervals (CI). Out of a total of 2200 records, 8 observational studies with a sample size of 301 patients with MG and 454 HCs were included in the systematic review. Meta-analysis revealed lower values of expiration/inspiration ratio (g = -0.45, I2 = 74.7), baroreflex sensitivity (g = -0.56, 95%CI -0.80, -0.33; I2 = 0.3), percentage of adjacent NN intervals differing by more than 50 ms (g = -1.2, I2 = 82.8), square root of the mean of squared differences between successive beat intervals (g = -1.94, I2 = 95.1), mean of the standard deviations of all NN intervals (g = -0.83, 95%CI -1.37, -0.28; I2 = 55.5), and high frequency of HRV during tilt (g = -0.75, 95%CI -0.11, -0.39; I2 = 0). MG patients vs. HCs had higher systolic blood pressure (g = 0.39; I2 = 56.1), sympathovagal balance at rest/during tilt (LF/HF-RRIsupine, g = 0.44; I2 = 0; LF/HF-RRItilt, g = 0.86; I2 = 0; LF/HFtilt, g = 0.40; I2 = 0). As a group, MG patients have altered cardiac autonomic function, including decreased parasympathetic function, lower baroreflex sensitivity, and higher sympathovagal balance at rest and during orthostatic challenges.

Astragaloside IV ameliorates experimental autoimmune myasthenia gravis by regulating CD4 + T cells and altering gut microbiota

BACKGROUND

Myasthenia gravis (MG) is an antibody-mediated autoimmune disease and its pathogenesis is closely related to CD4 + T cells. In recent years, gut microbiota is considered to play an important role in the pathogenesis of MG. Astragaloside IV (AS-IV) is one of the main active components extracted from Astragalus membranaceus and has immunomodulatory effects. To study the immunomodulatory effect of AS-IV and the changes of gut microbiota on experimental autoimmune myasthenia gravis (EAMG) mice, we explore the possible mechanism of AS-IV in improving MG.

METHODS

In this study, network pharmacology was utilized to screen the crucial targets of AS-IV in the treatment of MG. Subsequently, a Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed to identify potential pathways through which AS-IV acts against MG. Furthermore, experimental investigations were conducted to validate the underlying mechanism of AS-IV in MG treatment. Before modeling, 5 mice were randomly selected as the control group (CFA group), and the other 10 were induced to EAMG model. These mice were randomly divided into EAMG group and EAMG + AS-IV group, n = 5/group. In EAMG + AS-IV group, AS-IV was administered by gavage. CFA and EAMG groups were given the same volume of PBS. Body weight, grip strength and clinical symptoms were assessed and recorded weekly. At the last administration, the feces were collected for 16S RNA microbiota analysis. The levels of Treg, Th1 and Th17 cells in spleen and Th1 and Th17 cells in thymus were detected by flow cytometry. The levels of IFN-γ, IL-17 and TGF-β in serum were measured by ELISA. Furthermore, fecal microbial transplantation (FMT) experiments were performed for exploring the influence of changed intestinal flora on EAMG. After EAMG model was induced, the mice were treated with antibiotics daily for 4 weeks to germ-free. Then germ-free EAMG mice were randomly divided into two groups: FMT EAMG group, FMT AS-IV group, n = 3/group. Fecal extractions from EAMG and EAMG + AS-IV groups as gathered above were used to administered daily to the respective groups for 4 weeks. Body weight, grip strength and clinical symptoms were assessed and recorded weekly. The levels of Treg, Th1 and Th17 cells in spleen and Th1 and Th17 cells in thymus were detected at the last administration. The levels of IFN-γ, IL-17 and TGF-β in serum were measured by ELISA.

RESULTS

The network pharmacology and KEGG pathway analysis revealed that AS-IV regulates T cell pathways, including T cell receptor signaling pathway and Th17 cell differentiation, suggesting its potential in improving MG. Further experimental verification demonstrated that AS-IV administration improved muscle strength and body weight, reduced the level of Th1 and Th17 cells, enhanced the level of Treg cells, and resulted in alterations of the gut microbiota, including changes in beta diversity, the Firmicutes/Bacteroidetes (F/B) ratio, and the abundance of Clostridia in EAMG mice. We further conducted FMT tests and demonstrated that the EAMG Abx-treated mice which were transplanted the feces of mice treated with AS-IV significantly alleviated myasthenia symptoms, reduced Th1 and Th17 cells levels, and increased Treg cell levels.

CONCLUSION

This study speculated that AS-IV ameliorates EAMG by regulating CD4 + T cells and altering the structure and species of gut microbiota of EAMG.

Choices and Challenges With Treatment of Myasthenia Gravis in Pregnancy: A Systematic Review

Myasthenia gravis (MG) is an autoimmune disease affecting young women in their second and third decades, coinciding with their reproductive years. We aim to explore the choices and challenges in the treatment of MG in pregnancy. Cochrane, PubMed, Google Scholar, and Embase were the four databases systematically searched for studies with patients reporting pregnancy outcomes for women with MG during pregnancy using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) technique. Quality assessment was done using the Joanna Briggs Institute critical tool (JBI, Adelaide, Australia) for methodological quality. From 2000 to 2023, 40 studies from database search results were considered. There is a substantial risk of complications with MG, especially if it appears during pregnancy. In particular, widespread weakness is a cause of severe, life-threatening disorders, but several treatment options are available.

Myasthenia gravis. Update on diagnosis and therapy

Myasthenia gravis is an autoimmune disease caused by the presence of specific antibodies targeting different postsynaptic components of the neuromuscular junction, and is clinically characterized by the presence of fatigueable muscle weakness. In the etiopathogenesis plays a central role the thymus and the most frequently detected pathogenic autoantibodies are targeted to the acetylcholine receptor. The increase in the knowledge of the immunological components of the neuromuscular junction in the last two decades has been fundamental to identify new pathogenic antibodies, reduce the percentage of patients with seronegative myasthenia, and propose a classification of patients into subgroups with clinical-therapeutic interest. In addition, in recent years, new drugs have been developed for the treatment of patients with myasthenia gravis that are refractory to conventional immunosuppressive treatment.

Myasthenia Gravis Exacerbation Following COVID-19 Vaccine: A Case Report

Background: Vaccination remains the mainstay of strategy for prevention of Coronavirus Disease-2019 (COVID-19). AZD1222 (AstraZeneca vaccine) was distributed in Sudan by the COVID-19 Vaccines Global Access facility in March 2021. It was added to the emergency use list by the WHO in mid-February 2021. However, vaccine safety among patients with autoimmune diseases, such as myasthenia gravis (MG), is yet to be established. MG is a relatively rare illness that could result in life-threatening complications. Myasthenic crisis is considered the most serious complication of MG that can lead to death due to aspiration and respiratory failure. The case: We report the case of a 37-year-old Sudanese female who presented to the emergency room with an exacerbation of her normally well-controlled MG following her second dose of AZD1222 vaccination. She continued to deteriorate and was admitted to the intensive care unit, where she was intubated and placed on a mechanical ventilator. The low-income setting was a major barrier in obtaining intravenous immunoglobulin until the patient died. Our study aims to present an MG case with features of MG exacerbation following administration of a second dose of AZD1222. Conclusion: Little is known about the effect of different COVID-19 vaccines on subgroups of patients with autoimmune diseases like MG. In our case, an exacerbation of MG may have been precipitated by the COVID-19 AstraZeneca vaccine. Therefore, more efforts and experimental studies may be needed, with closer vigilance in MG patients

Microbiota dysbiosis and myasthenia gravis: Do all roads lead to Rome?

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.

Epidemiology and treatment of myasthenia gravis: a retrospective study using a large insurance claims dataset in Germany

Myasthenia gravis (MG) is a rare, chronic autoimmune disease with symptoms of fluctuating muscular weakness and fatigability. The aim of this retrospective cohort study was to estimate the prevalence and incidence of MG in Germany, and to understand the burden of disease and treatment patterns, based on anonymized German claims data. Two patient samples were identified: (1) incident MG patients with newly onset disease between 2015 and 2019, and (2) prevalent MG patients in 2019. In total, 775 incident MG patients with a mean age of 66.9 years; and 1,247 prevalent MG patients with a mean age of 68.6 years were included. The prevalence for Germany was estimated to be 39.3/100,000 on 31/12/2019; the incidence in 2019 was 4.6 cases/100,000 persons. The 12-month mortality was 5.7. For 31.5% of the incident patients, no MG treatment was observed in the first year after the index date. Of all incident patients, 29.9% experienced an exacerbation, and 6.7% a myasthenic crisis during the observation. Our study indicates that a substantial proportion of MG patients remains untreated. Many MG patients still experience exacerbations / MG crises. MG seems to be associated with an excess mortality in comparison to the general non-MG population.

Real-world application of plasmapheresis for neurological disease: Results from the Japan-Plasmapheresis Outcome and Practice Patterns Study

INTRODUCTION

Plasmapheresis is a well-recognized treatment for autoimmune neurological diseases in Japan. However, the practice varies depending on the facility, and the actual treatment conditions are unclear.

METHODS

To clarify real-world conditions, a prospective observational study was conducted on patients with neurological diseases who were scheduled to receive plasmapheresis. A dataset was analyzed that included 887 treatments from 210 patients with myasthenia gravis (MG), multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and other diseases for 82, 30, 24, and 74 patients, respectively.

RESULTS

The types of plasmapheresis performed included immunoadsorption plasmapheresis, plasma exchange, and double filtration plasmapheresis with 620, 213, and 54 treatments, respectively. Approximately, 60% of the treatments were performed using peripheral blood access alone. Non-serious adverse events were observed in 10 patients.

CONCLUSIONS

A statistically significant improvement was observed after plasmapheresis in patients with MG, MS, and NMOSD. These were evaluated using the modified Rankin Scale.

Myasthenia gravis and congenital myasthenic syndromes

Myasthenia gravis is an autoimmune disorder caused by antibodies against elements in the postsynaptic membrane at the neuromuscular junction, which leads to muscle weakness. Congenital myasthenic syndromes are rare and caused by mutations affecting pre- or postsynaptic function at the neuromuscular synapse and resulting in muscle weakness. MG has a prevalence of 150-250 and an annual incidence of 8-10 individuals per million. The majority has disease onset after age 50 years. Juvenile MG with onset in early childhood is more common in East Asia. MG is subgrouped according to type of pathogenic autoantibodies, age of onset, thymus pathology, and generalization of muscle weakness. More than 80% have antibodies against the acetylcholine receptor. The remaining have antibodies against MuSK, LRP4, or postsynaptic membrane antigens not yet identified. A thymoma is present in 10% of MG patients, and more than one-third of thymoma patients develop MG as a paraneoplastic condition. Immunosuppressive drug therapy, thymectomy, and symptomatic drug therapy with acetylcholine esterase inhibitors represent cornerstones in the treatment. The prognosis is good, with the majority of patients having mild or moderate symptoms only. Most congenital myasthenic syndromes are due to dysfunction in the postsynaptic membrane. Symptom debut is in early life. Symptomatic drug treatment has sometimes a positive effect.

A Case Report and 31-Case Study: Does Takotsubo Cardiomyopathy in Myasthenia Gravis Patients Have a High Mortality Rate?

Myasthenia gravis is an autoimmune disorder in which antibodies are formed against post-synaptic nicotinic acetylcholine receptors that lead to impeded muscle contraction and commonly affects the oculomotor muscles. Takotsubo cardiomyopathy (TTC) is a dilated cardiomyopathy that can mimic a myocardial infarction and causes reversible systolic dysfunction. This is a case of a 66-year-old Caucasian male with a known history of ocular myasthenia gravis that presented to the emergency room with worsening dyspnea secondary to a myasthenic crisis. One day, following admission, his shortness of breath failed to improve and was found to meet the diagnostic criteria for takotsubo cardiomyopathy. A brief review of 31 previous cases summarizes the current case reports, patterns, and mortality associated with the myasthenic crisis associated with TTC.

Pharmacotherapy of Generalized Myasthenia Gravis with Special Emphasis on Newer Biologicals

Myasthenia gravis (MG) is a chronic, fluctuating, antibody-mediated autoimmune disorder directed against the post-synaptic neuromuscular junctions of skeletal muscles, resulting in a wide spectrum of manifestations ranging from mild to potentially fatal. Given its unique natural course, designing an ideal trial design for MG has been wrought with difficulties and evidence in favour of several of the conventional agents is weak as per current standards. Despite this, acetylcholinesterases and corticosteroids have remained the cornerstones of treatment for several decades with intravenous immunoglobulins (IVIG) and therapeutic plasma exchange (PLEX) offering rapid treatment response, especially in crises. However, the treatment of MG entails long-term immunosuppression and conventional agents are viable options but take longer to act and have a number of class-specific adverse effects. Advances in immunology, translational medicine and drug development have seen the emergence of several newer biological agents which offer selective, target-specific immunotherapy with fewer side effects and rapid onset of action. Eculizumab is one of the newer agents that belong to the class of complement inhibitors and has been approved for the treatment of refractory general MG. Zilucoplan and ravulizumab are other agents in this group in clinical trials. Neisseria meningitis is a concern with all complement inhibitors, mandating vaccination. Neonatal Fc receptor (FcRn) inhibitors prevent immunoglobulin recycling and cause rapid reduction in antibody levels. Efgartigimod is an FcRn inhibitor recently approved for MG treatment, and rozanolixizumab, nipocalimab and batoclimab are other agents in clinical trial development. Although lacking high quality evidence from randomized clinical trials, clinical experience with the use of anti-CD20 rituximab has led to its use in refractory MG. Among novel targets, interleukin 6 (IL6) inhibitors such as satralizumab are promising and currently undergoing evaluation. Cutting-edge therapies include genetically modifying T cells to recognise chimeric antigen receptors (CAR) and chimeric autoantibody receptors (CAAR). These may offer sustained and long-term remissions, but are still in very early stages of evaluation. Hematopoietic stem cell transplantation (HSCT) allows immune resetting and offers sustained remission, but the induction regimens often involve serious systemic toxicity. While MG treatment is moving beyond conventional agents towards target-specific biologicals, lack of knowledge as to the initiation, maintenance, switching, tapering and long-term safety profile necessitates further research. These concerns and the high financial burden of novel agents may hamper widespread clinical use in the near future.

Effect of Fufang Huangqi Decoction on the Gut Microbiota in Patients With Class I or II Myasthenia Gravis

Objective

To investigate the effect of Fufang Huangqi Decoction on the gut microbiota in patients with class I or II myasthenia gravis (MG) and to explore the correlation between gut microbiota and MG (registration number, ChiCTR2100048367; registration website, http://www.chictr.org.cn/listbycreater.aspx; NCBI: SRP338707).

Methods

In this study, microbial community composition and diversity analyses were carried out on fecal specimens from MG patients who did not take Fufang Huangqi Decoction (control group, n = 8) and those who took Fufang Huangqi Decoction and achieved remarkable alleviation of symptoms (medication group, n = 8). The abundance, diversity within and between habitats, taxonomic differences and corresponding discrimination markers of gut microbiota in the control group and medicated group were assessed.

Results

Compared with the control group, the medicated group showed a significantly decreased abundance of Bacteroidetes (P < 0.05) and significantly increased abundance of Actinobacteria at the phylum level, a significantly decreased abundance of Bacteroidaceae (P < 0.05) and significantly increased abundance of Bifidobacteriaceae at the family level and a significantly decreased abundance of Blautia and Bacteroides (P < 0.05) and significantly increased abundance of Bifidobacterium, Lactobacillus and Roseburia at the genus level. Compared to the control group, the medicated group had decreased abundance, diversity, and genetic diversity of the communities and increased coverage, but the differences were not significant (P > 0.05); the markers that differed significantly between communities at the genus level and influenced the differences between groups were Blautia, Bacteroides, Bifidobacterium and Lactobacillus.

Conclusions

MG patients have obvious gut microbiota-associated metabolic disorders. Fufang Huangqi Decoction regulates the gut microbiota in patients with class I or II MG by reducing the abundance of Blautia and Bacteroides and increasing the abundance of Bifidobacterium and Lactobacillus. The correlation between gut microbiota and MG may be related to cell-mediated immunity.

Mitochondrial dynamics and biogenesis indicators may serve as potential biomarkers for diagnosis of myasthenia gravis

Due to challenges in diagnosing myasthenia gravis (MG), identifying novel diagnostic biomarkers for this disease is essential. Mitochondria are key organelles that regulate multiple physiological functions, such as energy production, cell proliferation and cell death. In the present study, Mfn1/2, Opa1, Drp1, Fis1, AMPK, PGC-1α, NRF-1 and TFAM were compared between patients with MG and healthy subjects to identify potential diagnostic biomarkers for MG. Blood samples were collected from 50 patients with MG and 50 healthy subjects. The participants' demographic information and routine blood test results were recorded. Mitochondrial dynamics were evaluated and levels of Mfn1/2, Opa1, Drp1, Fis1, AMPK, PGC-1α, NRF-1 and TFAM were determined in peripheral blood mononuclear cells using western blotting and reverse transcription-quantitative PCR, respectively. Receiver operating characteristic curve analysis was used to evaluate the diagnostic accuracy of these indicators. The areas under the curve values of Mfn1/2, Opa1, Drp1, Fis1,AMPK, PGC-1α, NRF-1 and TFAM were 0.5408-0.8696. Compared with control subjects, mRNA expression levels of Mfn1/2, Opa1, AMPK, PGC-1α, NRF-1 and TFAM were lower, while those of Drp1 and Fis1 were higher in patients with MG. The protein expression levels of all these molecules were lower in patients with MG than in control subjects. These results suggested that mitochondrial dynamics and biogenesis indicators may be diagnostic biomarkers for MG.

Ocular myasthenia gravis: a review and practical guide for clinicians

Myasthenia gravis is a rare autoimmune disease characterised by autoantibodies preventing normal function of acetylcholine receptors at the post-synaptic membrane of the neuromuscular junction. This causes weakness of skeletal muscles that can be variable and fatigable, and often manifests as ptosis and/or diplopia, with 60% of patients demonstrating ocular features at onset, and thus may present initially to eye care practitioners. Approximately 15% of patients have ocular myasthenia gravis, where symptoms remain restricted to this distribution. The majority of patients have blocking antibodies against the acetylcholine receptor, but antibodies directed against other related targets account for a smaller proportion and are associated with specific phenotypes. Associations with both thymoma and with other autoimmune phenomena (particularly thyroid disease) can occur. Clinical examination can identify characteristic findings including fatigable ptosis and Cogan's lid twitch sign. Investigations to confirm the diagnosis include simple office-based procedures such as the ice test, and testing for serum autoantibodies, as well as electrophysiological testing such as repetitive nerve stimulation and single-fibre electromyography. The management of ocular myasthenia gravis is discussed, including non-pharmacological options, pyridostigmine, corticosteroids, other immunosuppressive agents, and thymectomy. The goals of management are to alleviate symptoms, and where possible prevent chronic disability or progression to generalised myasthenia gravis.

Exacerbation of myasthenia gravis following corticosteroid treatment: what is the evidence? A systematic review

Corticosteroids (CS) are among the most widely- used immunosuppressive agents for immune-mediated conditions, including myasthenia gravis (MG). While their effectiveness in MG is documented and supported in the clinical practice over several decades, one of the main drawbacks of treatment results from the notion that MG patients may experience symptom worsening following CS treatment initiation. This may lead to the administration of lower than necessary doses of CS for the disorder, or even avoiding them altogether. As a consequence, some patients may not receive the optimal treatment to control their disease. In the present review, we analyzed 27 relevant publications and determined the prevalence of clinical exacerbation following CS treatment, its' severity and relation to the type and dose of CS. The rate of MG exacerbation is highest with the administration of cortisone, intermediate with prednisone, and lowest with methylprednisolone. High dose daily or alternate-day prednisone is associated with exacerbation more frequently than low-dose treatment, but most exacerbations are of mild to moderate severity. Other factors related to increased risk of an initial exacerbation include older age, generalized MG, bulbar symptoms, disease severity, presence of thymoma, and thymectomy. However, the current information is based mostly on heterogeneous studies of low quality, and prospective clinical trials designed to compare between the various agents and doses and assess the rate and severity of the exacerbation by a unified scale are warranted.

Development of the Myasthenia Gravis (MG) Symptoms PRO: a case study of a patient-centred outcome measure in rare disease

BACKGROUND

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disease, characterised by fluctuating muscle weakness which makes it challenging to assess symptom severity. Mixed methods psychometrics (MMP), which combines evidence from qualitative research and modern psychometrics, is a versatile approach to the development of patient-centred outcome measures (PCOM) in the context of rare disease. Our objective was to develop the MG Symptom patient-reported outcome (PRO) to assess key aspects of MG severity from the patient perspective.

METHODS

We used MMP to develop a novel PRO instrument in a multi-step process. An initial conceptual model for MG patient experience was developed and expanded based on preliminary literature review and two waves of concept elicitation interviews with people with MG (Step 1). Based on this, the novel PRO instrument, the MG Symptoms PRO, was drafted. The draft instrument was refined by combining qualitative and quantitative data collected in a Phase 2 clinical study (Step 2).

RESULTS

Findings from the literature review and concept elicitation interviews (n = 96) indicated that patient experience in MG includes proximal muscle weakness symptoms related to several body parts, along with muscle weakness fatigability and general fatigue. Then, a set of 42 items across five scales (ocular-, bulbar-, and respiratory muscle weakness, physical fatigue, and muscle weakness fatigability) was developed. Qualitative evidence endorsed its relevance, clarity, and ease of completion; quantitative analysis with Rasch measurement theory methods demonstrated strong measurement properties, including good targeting and high reliability. Classical test theory analyses showed adequate reliability of the instrument and mild to moderate correlations with other widely used MG-specific outcome measures.

CONCLUSIONS

The MG Symptoms PRO has potential to be used both to measure treatment benefit in clinical trials and monitor symptom severity in clinical practice. Its component scales were purposefully designed to stand alone, enhancing interpretability of scores given the heterogeneity of MG, and enabling modular use. Compared with existing MG PROs, it contains more detailed assessments of muscle weakness and muscle weakness fatigability symptoms, which are of key importance to people with MG. The MMP approach used may serve as a case study for developing PCOMs across rare disease indications.

Laboratory Investigation of Hybrid IgG4 k/λ in MuSK Positive Myasthenia Gravis

Myasthenia gravis with antibodies (Abs) against the muscle-specific tyrosine kinase (MuSK) is a rare autoimmune disorder (AD) of the neuromuscular junction (NMJ) and represents a prototype of AD with proven IgG4-mediated pathogenicity. Thanks to the mechanism of Fab-arm exchange (FAE) occurring in vivo, resulting MuSK IgG4 k/λ Abs increase their interference on NMJ and pathogenicity. The characterization of hybrid MuSK IgG4 as a biomarker for MG management is poorly investigated. Here, we evaluated total IgG4, hybrid IgG4 k/λ, and the hybrid/total ratio in 14 MuSK-MG sera in comparison with 24 from MG with Abs against acetylcholine receptor (AChR) that represents the not IgG4-mediated MG form. In both subtypes of MG, we found that the hybrid/total ratio reflects distribution reported in normal individuals; instead, when we correlated the hybrid/total ratio with specific immune-reactivity we found a positive correlation only with anti-MuSK titer, with a progressive increase of hybrid/total mean values with increasing disease severity, indirectly confirming that most part of hybrid IgG4 molecules are engaged in the anti-MuSK pathogenetic immune-reactivity. Further analysis is necessary to strengthen the significance of this less unknown biomarker, but we retain it is full of a diagnostic-prognostic powerful potential for the management of MuSK-MG.

Detecting myasthenia gravis as a cause of unclear dysphagia with an endoscopic tensilon test

Aims:

The flexible endoscopic evaluation of swallowing-tensilon test (FTT) was developed to diagnose myasthenia gravis (MG) in patients with unclear pharyngeal dysphagia. The purpose of this study was to determine sensitivity and specificity of the FTT and compare its diagnostic validity with that of other diagnostic markers.

Methods:

In this single-centre pragmatic clinical cohort study, a total of 100 patients with unclear pharyngeal dysphagia were eligible to undergo FTT. All patients were subjected to FTT and subsequently followed up clinically. FTT was considered positive if a significant improvement of pharyngeal swallowing function could be objectified endoscopically upon administration of edrophonium chloride. In addition, repetitive nerve stimulation test and serum MG antibody analysis were conducted.

Results:

All subjects (mean age 62.5 ± 14.1 years, female 33) underwent FTT without any complications. According to the results of the diagnostic procedures and based on long-term clinical follow-up for at least 3 years, 51 patients were finally diagnosed with MG. The sensitivity and specificity for the FTT was 88.2% and 95.9%, respectively. Application of the Cochran’s Q test showed statistically significant heterogeneity among the diagnostic tests, with results indicating FTT performance to be more accurate than the repetitive nerve stimulation results (p < 0.001) and comparable with serum antibody tests (p > 0.99).

Conclusion:

FTT has excellent clinical properties to be used routinely in the assessment of dysphagia with isolated or predominant pharyngeal muscle involvement allowing rapid and accurate diagnosis of MG.

Upregulation of circ-FBL promotes myogenic proliferation in myasthenia gravis by regulation of miR-133/PAX7

Myasthenia gravis (MG) is a disease involving neuromuscular transmission that causes fatigue of skeletal muscles and fluctuating weakness. It has been shown that impairment of myogenic differentiation and myofiber maturation may be the underlying cause of MG. In this study, we detected the abnormal expression of circular RNA (circRNA) using next‐generation sequencing in patients with MG. We then investigated the regulatory mechanism and the relationship among circRNA, microRNA, and messenger RNA using quantitative reverse‐transcription polymerase chain reaction, bioinformatics analysis, and luciferase report analysis. The expression of inflammatory cytokines and regulatory T lymphocytes was shown to be increased. Circ‐FBL was significantly increased in MG patients. Bioinformatics and luciferase report analyses confirmed that miR‐133 and PAX7 were the downstream targets of circ‐FBL. Overexpression of circ‐FBL promoted myoblast proliferation by regulation of miR‐133/PAX7. Taken together, our study showed that upregulation of circ‐FBL promoted myogenic proliferation in patients with MG by regulating miR‐133/PAX7.

Role of Th22 Cells in the Pathogenesis of Autoimmune Diseases

Upon antigenic stimulation, naïve CD4+T cells differentiate into different subsets and secrete various cytokines to exert biological effects. Th22 cells, a newly identified CD4+T cell subset,are distinct from the Th1, Th2 and Th17 subsets. Th22 cells secrete certain cytokines such as IL-22, IL-13 and TNF-α, but not others, such as IL-17, IL-4, or interferon-γ (IFN-γ), and they express chemokine receptors CCR4, CCR6 and CCR10. Th22 cells were initially found to play a role in skin inflammatory diseases, but recent studies have demonstrated their involvement in the development of various autoimmune diseases. Here, we review research advances in the origin, characteristics and effector mechanisms of Th22 cells, with an emphasis on the role of Th22 cells and their main effector cytokine IL-22 in the pathogenesis of autoimmune diseases. The findings presented here may facilitate the development of new therapeutic strategies for targeting these diseases.

A Case of COVID-19 Vaccine Causing a Myasthenia Gravis Crisis

Myasthenia gravis is a rare disease of the neuromuscular junction subsequently affecting the bulbar, respiratory, and extremity skeletal muscles. It is an autoimmune disease in which antibodies target the acetylcholine receptor (AChR), preventing transmission of the excitatory cascade during muscle contraction. Myasthenia gravis is typically well controlled using acetylcholinesterase inhibitors, steroids, immunosuppressant agents, and/or thymectomies. However, exacerbations can be induced by infection or medications. This is particularly important during the coronavirus disease 2019 (COVID-19) pandemic in which myasthenia gravis patients have been known to have poorer outcomes. We report a very rare presentation of a myasthenia gravis crisis induced by the Moderna COVID-19 vaccine.

[Sleep disorders in patients with myastenia gravis]

This review analyzes publications that present data on sleep disorders in patients with myasthenia gravis (MG). The analysis is based on domestic and foreign publications that are freely available over the past 30 years. Sleep disorders, the most significant of which are sleep-related respiratory disorders, are one of the factors that cause quality of life decreasing and mortality in patients with neuromuscular diseases. The issues of prevalence of breathing disorders during sleep, relationship of these disorders with clinical and immunological characteristics of disease, demographic indicators are studied. The influence of sleep breathing disorders on quality of life and affective sphere of patients is discussed. Most studies prove that sleep-related respiratory disorders occur in patients with MG significantly more often than in general population. Some studies show a high prevalence of poor sleep quality, excessive daytime sleepiness in patients with MG, while others do not report such associations. However, studies that failed to establish an association with MG and sleep disturbances were of small sample sizes. Thus, given the inconclusive evidence and limited literature, further study of sleep disorders in patients with MG is needed. The topic is relevant and requires further development.

The mitochondrial biogenesis signaling pathway is a potential therapeutic target for myasthenia gravis via energy metabolism (Review)

Myasthenia gravis (MG) is an autoantibody-mediated autoimmune disease that is characterized by muscle weakness and fatigue. Traditional treatments for MG target the neuromuscular junction (NMJ) or the immune system. However, the efficacy of such treatments is limited, and novel therapeutic options for MG are urgently required. In the current review, a new therapeutic strategy is proposed based on the mitochondrial biogenesis and energy metabolism pathway, as stimulating mitochondrial biogenesis and the energy metabolism might alleviate myasthenia gravis. A number of cellular sensors of the energy metabolism were investigated, including AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1). AMPK and SIRT1 are sensors that regulate cellular energy homeostasis and maintain energy metabolism by balancing anabolism and catabolism. Peroxisome proliferator-activated receptor γ coactivator 1α and its downstream transcription factors nuclear respiratory factors 1, nuclear respiratory factors 2, and transcription factor A are key sensors of mitochondrial biogenesis, which can restore mitochondrial DNA and produce new mitochondria. These processes help to control muscle contraction and relieve the symptoms of MG, including muscle weakness caused by dysfunctional NMJ transmission. Therefore, the present review provides evidence for the therapeutic potential of targeting mitochondrial biogenesis for the treatment of MG.

Features and roles of T helper 22 cells in immunological diseases and malignancies

T helper 22 (Th22) cell populations are a newly identified subset of CD4+  T cells that primarily mediate biological effects on the epithelial barrier through interleukin (IL)-22. Although, new studies showed that both Th22 and IL-22 are closely associated with the pathogenesis of inflammatory, autoimmune and allergic disease as well as malignancies. In this review, we aim to describe the development and characteristics of Th22 cells as well as their roles in the immunopathogenesis of immune-related disorders and cancer.

Trauma-induced myasthenia gravis: coincidence or causal relationship?

We report a case of a 55-year-old man presenting with diplopia, masticatory weakness and dysarthria several weeks post multitrauma. The clinical suspicion of myasthenia gravis (MG) was supported with positive acetylcholine receptor antibodies and abnormal repetitive stimulation study. He responded well to pyridostigmine, intravenous immunoglobulin and oral prednisolone. In this report, we describe the timing and progression of MG in our patient, and review the literature pertaining to the relationship between trauma and MG. The search for definitive evidence of causation may be impractical, but should not delay the recognition and management of a treatable condition.

Myasthenia Gravis Related to Small Cell Lung Carcinoma

Myasthenia gravis is a neuromuscular disease that causes weakness in skeletal muscles because of the presence of acetylcholine receptor antibodies. These antibodies produce a compromise in the end-plate potential, reducing the safety factor for effective synaptic transmission. Clinically, this manifests as muscle weakness and, in severe cases, respiratory failure.

There is widespread knowledge about the association between small cell lung carcinoma and Lambert- Eaton myasthenic syndrome, but not with other neuromuscular disorders, such as myasthenia gravis.

We present a patient with small cell lung carcinoma who presented weakness affecting the proximal muscles over the last three years, and electromyography findings suggesting myasthenia gravis. After this electrodiagnosis, analytical tests showed an increase in anti-acetylcholine receptor antibodies.

Given these findings, we can affirm that neurophysiological tests provide a significant value in diagnosing myasthenia gravis, as anti-acetylcholine receptor antibodies were negative at the moment of the electromyography’s performance. Likewise, it is essential to consider a paraneoplastic syndrome in this type of carcinoma.

Management of thymomatous myasthenia gravis - Case report of a rare Covid19 infection sequelae

Introduction

SARS CoV19 infection can predispose to many autoimmune and neurological conditions, thymomatous myasthenia gravis being one of them. The rarity of these case poses therapeutic dilemmas about their further management.

Presentation of case

A 61 year old gentleman who had covid19 infection 2 months back, presented with new onset myasthenia gravis and an anterior mediastinal mass. He was diagnosed as a case of anti acetyl choline receptor antibody positive thymomatous myasthenia gravis. The patient was posted for video assisted thoracoscopic excision of thymoma. The procedure was uneventful and patient was discharged with improvement in myasthenic symptoms. Histopathological examination confirmed the diagnosis of WHO Type A Spindle cell thymoma.

Discussion

SARS CoV19 infection is associated with an array of autoimmune disorders due to various proposed phenomenon including molecular mimicry and loss of immune tolerance. Post infectious thymomatous myasthenia gravis is extremely uncommon, and can be managed with open, minimally invasive or robotic approach.

Conclusion

This is the first documented case of post covid19 infection thymomatous myasthenia gravis to the best of our knowledge, managed with minimally invasive thoracoscopic surgery. Further research is required for documentation of the natural history of the disease and therapeutic outcomes.

Impairment Mechanisms and Intervention Approaches for Aged Human Neuromuscular Junctions

The neuromuscular junction (NMJ) is a chemical synapse formed between a presynaptic motor neuron and a postsynaptic muscle cell. NMJs in most vertebrate species share many essential features; however, some differences distinguish human NMJs from others. This review will describe the pre- and postsynaptic structures of human NMJs and compare them to NMJs of laboratory animals. We will focus on age-dependent declines in function and changes in the structure of human NMJs. Furthermore, we will describe insights into the aging process revealed from mouse models of accelerated aging. In addition, we will compare aging phenotypes to other human pathologies that cause impairments of pre- and postsynaptic structures at NMJs. Finally, we will discuss potential intervention approaches for attenuating age-related NMJ dysfunction and sarcopenia in humans.

The Epidemiology and Clinical Manifestations of Autoimmunity in Selective IgA Deficiency

Selective immunoglobulin A deficiency (SIgAD) is the most common primary immunodeficiency, defined as an isolated deficiency of IgA (less than 0.07 g/L). Although the majority of people born with IgA deficiency lead normal lives without significant pathology, there is nonetheless a significant association of IgA deficiency with mucosal infection, increased risks of atopic disease, and a higher prevalence of autoimmune disease. To explain these phenomena, we have performed an extensive literature review to define the geoepidemiology of IgA deficiency and particularly the relative risks for developing systemic lupus erythematosus, hyperthyroidism, hypothyroidism, type 1 diabetes mellitus, Crohn's disease, ulcerative colitis, rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, and vitiligo; these diseases have strong data to support an association. We also note weaker associations with scleroderma, celiac disease, autoimmune hepatitis, immune thrombocytopenic purpura, and autoimmune hemolytic anemia. Minimal if any associations are noted with myasthenia gravis, lichen planus, and multiple sclerosis. Finally, more recent data provide clues on the possible immunologic mechanisms that lead to the association of IgA deficiency and autoimmunity; these lessons are important for understanding the etiology of autoimmune disease.

Myasthenia Gravis and its Association With Thyroid Diseases

Myasthenia gravis (MG) is a rare autoimmune neuromuscular junction disorder, and thyroid disorder is a disorder involving the thyroid receptor, of which Graves' disease (GD) is the most common autoimmune thyroid disorder, in which antibodies develop against thyroid receptors. Both may have similar clinical features. In myasthenia gravis, autoimmune antibodies develop against postsynaptic neuromuscular junction disrupting the neuromuscular transmission, resulting in fluctuating muscle weakness and fatigue. It is a disease of young women and older men. The two pathologies may coexist in a patient or can precede one another. Graves' disease (GD) among thyroid diseases is most often associated with MG. 

Similarities in clinical features lead to difficulty in distinguishing MG and GD. Despite the standard treatment of myasthenia gravis, including steroids, acetylcholinesterases, rituximab, immunosuppressants, and thymectomy, there is still an increased number of relapses and myasthenia crisis. Eculizumab and plasmapheresis are the two new treatment options for MG, with supporting evidence of marked improvement in recent studies. Myasthenia gravis and Graves' disease have a see-saw relationship. Treating one pathology may worsen the other, so physicians should always consider MG as a differential in patients of hyperthyroidism presenting with new symptoms of fatigue or respiratory failure or neuromuscular weakness.

In this comprehensive review article, we tried to establish an association between myasthenia gravis and Graves' disease (GD) by exploring currently available literature from PubMed. However, more studies need to be done to establish an association between pathologies.

A Patient with Fulminant Myasthenia Gravis Is Seropositive for Both AChR and LRP4 Antibodies, Complicated by Autoimmune Polyglandular Syndrome Type 3

This article describes the first reported case of myasthenia gravis (MG) seropositive for both acetylcholine receptor antibody and low-density lipoprotein receptor-related protein 4 antibody, complicated by autoimmune polyglandular syndrome (APS) type 3. The patient exhibited myasthenic weakness restricted to the ocular muscles and ptosis. Severe clinical deterioration ensued with predominant bulbar symptoms. MG rapidly worsened, the patient was intubated, and agranulocytosis due to thiamazole was also present, so it was necessary to perform thyroidectomy with tracheostomy and thymectomy in two phases. Both the double-seropositive MG and the APS were involved in the patient's rapid deterioration.

Eculizumab as a promising treatment in thymoma-associated myasthenia gravis

Myasthenia gravis is a chronic autoimmune disorder caused by antibodies directed against the neuromuscular junction. Some patients may have an associated thymoma, which confers a worse prognosis. Eculizumab, a monoclonal antibody that inhibits the activation of terminal complement, has recently been approved for the treatment of refractory generalized myasthenia gravis. This is an early case report of thymoma-associated refractory myasthenia gravis successfully treated with eculizumab in a real-world setting.

Incidence of AChR Ab-positive myasthenia gravis in Israel: A population-based study

BACKGROUND

The incidence of myasthenia gravis (MG) has traditionally been low, ranging between 2-6/10⁶ . Several recent epidemiological studies have reported a higher incidence. We, therefore, aimed to assess and characterize the incidence of MG in Israel.

METHODS

We retrospectively reviewed the records of all four laboratories that performed the acetylcholine receptor antibody (AChR Ab) test in Israel between 1994 and 2013 and documented the number of newly diagnosed seropositive MG patients each year. To assure that data indeed reflect only newly diagnosed patients, patient's names and ID numbers were screened at the Hadassah medical center database since 1978, the year when the test was first performed in Israel. In order to calculate the annual incidence of the disease, the population at risk was derived from the annual publication of the Israeli Central Bureau of Statistics.

RESULTS

The annual incidence of MG for this time period was 13.1/10⁶ inhabitants. The mean incidence of MG between 1994 and 2003 was 7.695/10⁶ /y, while the mean incidence between 2004 and 2013 was 18.49/10⁶ (P < .0001). Mean age of diagnosis between 1994 and 2003 was 56.65 ± 0.9351, while between 2004 and 2013, it was 59.89 ± 0.5336 (P = .0012). Male to female (M:F) incidence ratio in the years 1994-2003 and 2004-2013 was 2:3.2 and 3:1.8, respectively, reflecting increased incidence among males (P < .0001).

CONCLUSIONS

The incidence of MG in Israel has increased significantly during the last decade, especially among males of older age. These findings may reflect an etiological role of an environmental factor, increased awareness, and increased longevity in general.

Retrospective Analysis of Eculizumab in Patients with Acetylcholine Receptor Antibody-Negative Myasthenia Gravis: A Case Series

Background:

The role of the complement cascade in acetylcholine receptor antibody-negative (AChR–) myasthenia gravis (MG) is unclear.

Objective:

To assess the efficacy and tolerability of eculizumab (terminal complement inhibitor) in patients with AChR–MG.

Methods:

Retrospective chart review of data from six patients treated for 12 months with eculizumab for treatment-refractory, AChR–(by radioimmunoassay) generalized MG (gMG). The eculizumab dose was 900 mg/week for 4 weeks then 1200 mg every 2 weeks. Outcome measures were Myasthenia Gravis–Activities of Daily Living (MG-ADL) scores, number of exacerbations, and qualitative physical assessments based on selected items of the Quantitative Myasthenia Gravis evaluation (ptosis, double vision, eye closure, duration of ability to stretch out limbs).

Results:

All patients were female (mean age, 50.8 years). In the 12 months before eculizumab initiation, all measures were relatively stable. After its initiation, clinically meaningful reductions (≥2 points) in total MG-ADL scores were observed before or at 5 months and were maintained to Month 12 in all patients; mean (standard deviation [SD]) scores were 11.3 (0.9) and 5.0 (0.9), respectively. There was also a reduction in the mean (SD) number of exacerbations per patient, from 2.8 (1.2) to 0.3 (0.5) in the 12 months before and after eculizumab initiation, respectively. Physical assessment ratings were improved in all patients. Adverse events were reported in four patients, but all were mild and none were treatment-related.

Conclusions:

This small retrospective analysis provides preliminary evidence for the efficacy of eculizumab in treatment-refractory gMG that was AChR–according to radioimmunoassay. Larger, more robust studies are warranted to evaluate this further.

Newer Immunotherapies for the Treatment of Acute Neuromuscular Disease in the Critical Care Unit

OPINION STATEMENT

PURPOSE OF REVIEW: In this review, we discuss current treatment options for commonly encountered neuromuscular disorders in intensive care units. We will discuss epidemiology, pathophysiology, and acute and chronic treatment options for myasthenia gravis, Guillain-Barré syndrome, West Nile virus, Botulism, and amyotrophic lateral sclerosis.

RECENT FINDINGS

Eculizumab is the newest immunomodulator therapy approved by the Food and Drug Administration in treatment of myasthenia gravis, shown to improve long-term functional outcomes. Edaravone is the newest therapy in management of amyotrophic lateral sclerosis, shown to slow functional deterioration. Efgartigimod showed great promise in a phase 2 safety and efficacy trial in the treatment of stable generalized myasthenia gravis. Eculizumab was found to be safe in a small phase 2 trial for use in Guillain-Barré syndrome. Currently, therapies such as plasma exchange, intravenous immunoglobulins, and steroids remain the mainstay of treatment in the ICU for many neuromuscular disorders. While there are some newer immunotherapies available, few have been studied in the acute setting. However, with the advent of new immunotherapies and biologics, changes in these approaches may be on the horizon.