Long-term effect of thymectomy plus prednisone versus prednisone alone in patients with non-thymomatous myasthenia gravis: 2-year extension of the MGTX randomised trial

Single-Cell Transcriptomics Identifies a Prominent Role for the MIF-CD74 Axis in Myasthenia Gravis Thymus

BACKGROUND AND OBJECTIVES

Myasthenia gravis (MG) is an autoimmune disease most frequently caused by autoantibodies (auto-Abs) against the acetylcholine receptor (AChR) located at the neuromuscular junction. Thymic follicular hyperplasia is present in most of the patients with early-onset AChR-Ab+ MG (EOMG), but its cellular and molecular drivers and development remain poorly understood.

METHODS

We constructed a single cell-based transcriptional profile of lymphoid cell types in thymi from 11 immunotherapy-naïve patients with EOMG. Multiplex histology and ELISA were used to determine migration inhibitory factor (MIF) levels.

RESULTS

Within EOMG thymi, we consistently observed 6 distinct clusters of B-cell populations maturing toward germinal center (GC)-associated and Ab-secreting cells, featuring prominent GC activity, as indicated by substantial clonal expansions and cycling B-cell subsets. Cell-cell interactome predictions identified strong interactions between T cells and GC-associated and memory B cells, dominated by B-cell prosurvival signaling through the MIF-CD74 axis. Multiplex histology confirmed abundant expression of CD74 in MG thymic B cells. Circulating MIF levels in EOMG correlated with higher disease severity as assessed by Myasthenia Gravis Foundation of America status.

DISCUSSION

Our data not only illustrate and define hyperplastic thymic niches in MG as favorable environments for pathogenic B-cell proliferation, maturation, and persistence but also suggest that the MIF-CD74 axis should be investigated for potential novel therapeutic targeting in EOMG.

The Role of Exosomes in Central Immune Tolerance and Myasthenia Gravis

BACKGROUND

Immune homeostasis plays a crucial role in immunology andis dependent on both central and peripheral tolerance. Centraltolerance and peripheral tolerance occur in the thymus and thesecondary lymphoid tissues, respectively. Tolerance breakdown andimmune regulation defects can lead to autoimmune disorders. In thisreview article, we aimed to describe the role of exosomes inregulating central tolerance and provide a summary of their effectson the pathogenesis, diagnosis, and therapeutic potential inmyasthenia gravis (MG).

METHODS

Articles for this review wereidentified using the PubMed database.

RESULTS

As the primarylymphoid organ, the thymus is responsible for building an immunecompetent, yet self-tolerant of T-cell population. Thymic statesinclude thymoma, thymic hyperplasia, and thymic atrophy, which canexert a significant influence on the central immune tolerance andrepresent specific characteristics of MG. Previous studies have foundthat exosomes derived from human thymic epithelial cells carryantigen-presenting molecules and a wide range of tissue restrictedantigens, which may indicate a vital role of thymic exosomes in MG.Besides, exosomal miRNAs and lncRNAs may also play a critical role inthe pathophysiology of MG.

CONCLUSION

This review provides thetherapeutic and diagnostic potential of exosomes in MG patients.

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.

Eculizumab in thymoma-associated myasthenia gravis: a real-world cohort study

Background

Thymoma-associated myasthenia gravis (TAMG) is a subtype of myasthenia gravis (MG) that is associated with more severe symptoms and a relatively poor prognosis. Eculizumab, an inhibitor to target human C5 component of the complement cascade, is considered a treatment option for refractory generalized MG (gMG).

Objectives

To explore the safety and efficacy of eculizumab in patients with TAMG.

Design

This is an observational multicenter real-world cohort study to assess TAMG who were treated with eculizumab from June 2023 to June 2024.

Data sources and methods

Clinical features associated with thymoma-associated multi-organ autoimmunity (TAMA), Myasthenia Gravis Activities of Daily Living (MG-ADL) score, and the incidence of treatment-emergent adverse events (TEAEs) were prospectively collected.

Results

Overall, 42 patients with gMG were treated with eculizumab at 5 research centers, of whom 22 patients with TAMG were finally included. This cohort had a mean age of 51.5 ± 12.1 years and an average disease duration of 4.0 ± 4.3 years. Regarding thymomas, the World Health Organization (WHO) histological classification was primarily B2 and B3 (63.7%), and Masaoka staging was predominantly IV (45.5%). Nine participants (40.9%) switched from efgartigimod to eculizumab aiming at a better clinical improvement and reducing steroid use. By week 12, the MG-ADL score decreased to 4.8 ± 4.7 (baseline: 11.7 ± 6.0), and the corticosteroid dose reduced to 23.2 ± 26.5 mg (baseline: 41.8 ± 63.9 mg). Two patients with TAMA showed significant improvement in skin lesions and thrombocytopenia. Two TEAEs were recorded including COVID-19 and herpes labialis infection. Four patients (18.2%) died of respiratory or circulatory failure owing to thymoma metastasis.

Conclusion

This real-world study demonstrates the efficacy of eculizumab in achieving symptom control and corticosteroid reduction for TAMG. It may also be a therapeutic option for refractory TAMG and TAMA.

Trial registration

NCT04535843.

Targeted Treatments for Myasthenia Gravis in Children and Adolescents

Myasthenia gravis (MG) is an antibody-mediated disorder of the neuromuscular junction affecting children and adults. MG is a treatable condition with most patients requiring immunosuppression for disease control and/or remission. Juvenile myasthenia gravis (JMG) is rare in comparison with adult-onset MG but given the same underlying pathophysiology, treatment strategies are similar to those in adults. Until recently, there were only a few randomised controlled trials (RCTs) for MG treatments in adults and none in children, and management strategies were primarily based on expert consensus. In addition, treatment options for refractory MG cases have been severely limited, resulting in poor long-term quality of life in such patients due to the significant disease burden. Recently, there have been several RCTs focussing on novel therapeutic strategies with potentially promising outcomes, suggesting a change in MG management over the coming years and access to more effective and faster-acting drugs for MG patients. This paper will review current and new MG treatments including efgartigimod, eculizumab, rozanolixizumab, ravulizumab, and zilucoplan, with a focus on juvenile myasthenia gravis.

Circ_0076490 silencing inhibits MAPK1 expression to decrease the proliferation and increase apoptosis of Jurkat cells by regulating miR-144-3p in myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) is a both neuromuscular junction and antibody-mediated autoimmune disease, and its pathogenesis involves the regulation of circular RNAs (circRNAs). However, the role of circ_0076490 in MG and the underlying mechanism remain unknown.

METHODS

RNA levels of circ_0076490, microRNA-144-3p (miR-144-3p), and mitogen-activated protein kinase 1 (MAPK1) were detected by quantitative real-time polymerase chain reaction. Cell viability and proliferation were investigated by cell counting kit-8 and 5-Ethynyl-29-deoxyuridine assays, respectively. Cell cycle and apoptosis were assessed by flow cytometry analysis. The putative binding relationship of miR-144-3p and circ_0076490 or MAPK1 was predicted by circular RNA interactome and TargetScan online databases, respectively, and identified through dual-luciferase reporter assay and RNA pull-down assay.

RESULTS

We observed dramatic increases of circ_0076490 and MAPK1 expression and a decrease of miR-144-3p expression in the peripheral blood of MG patients in comparison with healthy controls. Reduced expression of circ_0076490 induced an inhibitory effect on the proliferation of Jurkat cells and a promoting effect on cell apoptosis. Additionally, miR-144-3p was identified as a target miRNA of circ_0076490, and its depletion attenuated circ_0076490 knockdown-mediated effects on the proliferation and apoptosis of Jurkat cells. MAPK1 was a target gene of miR-144-3p and its overexpression rescued decreased cell proliferation and increased cell apoptosis induced by miR-144-3p introduction. Furthermore, circ_0076490 regulated MAPK1 expression by interacting with miR-144-3p.

CONCLUSION

Circ_0076490 knockdown inhibited proliferation and induced apoptosis of Jurkat cells through the regulation of the miR-144-3p/MAPK1 axis, providing potential targets for developing improved therapy of MG.

New treatment strategies in Myasthenia gravis

Myasthenia gravis (MG) is a chronic autoimmune neuromuscular disorder characterized by muscle weakness and fatigue. The disease is primarily caused by antibodies targeting acetylcholine receptors (AChR) and muscle-specific kinase (MuSK) proteins at the neuromuscular junction. Traditional treatments for MG, such as acetylcholinesterase inhibitors, corticosteroids, and immunosuppressants, have shown efficacy but are often associated with significant long-term side effects and variable patient response rates. Notably, approximately 15% of patients exhibit inadequate responses to these standard therapies. Recent advancements in molecular therapies, including monoclonal antibodies, B cell-depleting agents, complement inhibitors, Fc receptor antagonists, and chimeric antigen receptor (CAR) T cell-based therapies, have introduced promising alternatives for MG treatment. These novel therapeutic approaches offer potential improvements in targeting specific immune pathways involved in MG pathogenesis. This review highlights the progress and challenges in developing and implementing these molecular therapies. It discusses their mechanisms, efficacy, and the potential for personalized medicine in managing MG. The integration of new molecular therapies into clinical practice could significantly transform the treatment landscape of MG, offering more effective and tailored therapeutic options for patients who do not respond adequately to traditional treatments. These innovations underscore the importance of ongoing research and clinical trials to optimize therapeutic strategies and improve the quality of life for individuals with MG.

Non-Coding RNAs in Myasthenia Gravis: From Immune Regulation to Personalized Medicine

Myasthenia gravis (MG) is an antibody-mediated autoimmune disorder characterized by altered neuromuscular transmission, which causes weakness and fatigability in the skeletal muscles. The etiology of MG is complex, being associated with multiple genetic and environmental factors. Over recent years, progress has been made in understanding the immunological alterations implicated in the disease, but the exact pathogenesis still needs to be elucidated. A pathogenic interplay between innate immunity and autoimmunity contributes to the intra-thymic MG development. Epigenetic changes are critically involved in both innate and adaptive immune response regulation. They can act as (i) pathological factors besides genetic predisposition and (ii) co-factors contributing to disease phenotypes or patient-specific disease course/outcomes. This article reviews the role of non-coding RNAs (ncRNAs) as epigenetic factors implicated in MG. Particular attention is dedicated to microRNAs (miRNAs), whose expression is altered in MG patients' thymuses and circulating blood. The long ncRNA (lncRNA) contribution to MG, although not fully characterized yet, is also discussed. By summarizing the most recent and fast-growing findings on ncRNAs in MG, we highlight the therapeutic potential of these molecules for achieving immune regulation and their value as biomarkers for the development of personalized medicine approaches to improve disease care.

Pre-thymectomy disease severity predicts outcome in acetylcholine receptor antibody-positive generalised myasthenia gravis

INTRODUCTION

There are only a few studies exploring post-thymectomy outcome in patients with acetylcholine receptor antibody (AChR-Ab)-positive generalised myasthenia gravis (MG).

OBJECTIVE

To assess the predictors of outcome in patients with AChR-Ab-positive generalised MG who underwent thymectomy.

METHODS

A retrospective study of 53 patients from a single neuroscience centre in the UK.

RESULTS

The mean disease duration from diagnosis was 6.2 ± 4.3 years. Pre-thymectomy, 37 patients had mild weakness affecting muscles other than ocular muscles, 11 patients had moderate weakness and 5 patients had severe weakness. 27/53 patients had thymoma. Post-thymectomy (mean duration of 5.7 ± 4.2 years), 34 patients (64%) had a good outcome characterised by Myasthenia Gravis Foundation of America Post-Intervention Status of complete stable remission (no symptoms or signs of MG for at least 1 year without any therapy) or pharmacological remission (no symptoms or signs of MG with some form of therapy) or minimal manifestations (no symptoms of functional limitations from MG but weakness on examination of some muscles with or without some form of therapy) on last follow-up visit. Having thymomatous or non-thymomatous MG did not predict the outcome. The only variable that did predict outcome was pre-thymectomy disease severity; patients with mild weakness before thymectomy had a favourable outcome. We found an accuracy of 83% predicting outcome (95% confidence interval (CI) 60%, 100%) with a sensitivity of 84% (95% CI 68%, 94%) and specificity of 81% (95% CI 54%, 96%).

CONCLUSION

Disease severity before thymectomy predicts outcome in patients with AChR-Ab-positive generalised MG.

Efgartigimod for generalized myasthenia gravis: A multicenter real-world cohort study in China

OBJECTIVE

Efgartigimod, a neonatal Fc receptor antagonist, facilitates antibody degradation including pathogenic IgGs. The ADAPT study demonstrated the tolerability and efficacy of efgartigimod in the treatment of generalized myasthenia gravis (gMG). However, very limited evidence is available for the Chinese population, and it remains inconclusive about which kind of patients are selected to preferentially receive efgartigimod in real-world settings.

METHODS

This multicenter cohort study included gMG patients treated at 14 neuromuscular reference centers in China. The Myasthenia Gravis Activities of Daily Living (MG-ADL) score, immunosuppressants, and the incidence of treatment-emergent adverse events (TEAEs) were prospectively collected.

RESULTS

Of the 1640 gMG admitted between September and December 2023, 61 (3.7%) received efgartigimod for at least one treatment cycle. Among them, 56 cases (92%) were anti-AChR antibody-positive, 4 were anti-MuSK antibody-positive, and 1 was seronegative. Thymoma-associated myasthenia gravis accounted for most cases (44%, 27 out of 61). The principal causes of efgartigimod initiation included MG acute exacerbation (MGAE) (48%, 29 out of 61) and myasthenic crisis (MC) (15%, 9 out of 61). Clinically meaningful improvement was rapidly achieved in 97% (58 out of 61) of patients at 1.3 ± 0.7 weeks. By week 12, the MG-ADL score reduced to 3.8 ± 4.1 (baseline:10.5 ± 5.2) for all participants, while it reduced to 4.0 ± 4.7 for MGAE and 3.8 ± 4.2 for MC, respectively. All but one TMG patient required no additional rescue therapies after efgartigimod initiation. 11.5% (7 out of 61) reported ≥1 TEAEs.

INTERPRETATION

This multicenter cohort study demonstrated the efficacy of efgartigimod in rapid control of gMG. Patients with MGAE or MC would benefit from efgartigimod treatment.

Treating myasthenia gravis beyond the eye clinic

Myasthenia gravis (MG) is one of the most well characterised autoimmune disorders affecting the neuromuscular junction with autoantibodies targeting the acetylcholine receptor (AChR) complex. The vast majority of patients present with ocular symptoms including double vision and ptosis, but may progress on to develop generalised fatiguable muscle weakness. Severe involvement of the bulbar muscles can lead to dysphagia, dysarthria and breathing difficulties which can progress to myasthenic crisis needing ventilatory support. Given the predominant ocular onset of the disease, it is important that ophthalmologists are aware of the differential diagnosis, investigations and management including evolving therapies. When the disease remains localised to the extraocular muscles (ocular MG) IgG1 and IgG3 antibodies against the AChR (including clustered AChR) are present in nearly 50% of patients. In generalised MG this is seen in nearly 90% patients. Other antibodies include those against muscle specific tyrosine kinase (MuSK) and lipoprotein receptor related protein 4 (LRP4). Even though decremental response on repetitive nerve stimulation is the most well recognised neurophysiological abnormality, single fibre electromyogram (SFEMG) in experienced hands is the most sensitive test which helps in the diagnosis. Initial treatment should be using cholinesterase inhibitors and then proceeding to immunosuppression using corticosteroids and steroid sparing drugs. Patients requiring bulbar muscle support may need rescue therapies including plasma exchange and intravenous immunoglobulin (IVIg). Newer therapeutic targets include those against the B lymphocytes, complement system, neonatal Fc receptors (FcRn) and various other elements of the immune system.

Does Surgical Removal of the Thymus Have Deleterious Consequences?

The role of immunosenescence, particularly the natural process of thymic involution during aging, is increasingly acknowledged as a factor contributing to the development of autoimmune diseases and cancer. Recently, a concern has been raised about deleterious consequences of the surgical removal of thymic tissue, including for patients who undergo thymectomy for myasthenia gravis (MG) or resection of a thymoma. This review adopts a multidisciplinary approach to scrutinize the evidence concerning the long-term risks of cancer and autoimmunity postthymectomy. We conclude that for patients with acetylcholine receptor antibody-positive MG and those diagnosed with thymoma, the removal of the thymus offers prominent benefits that well outweigh the potential risks. However, incidental removal of thymic tissue during other thoracic surgeries should be minimized whenever feasible.

Comparison of juvenile and adult myasthenia gravis in a French cohort with focus on thymic histology

Myasthenia gravis (MG) is an autoimmune disease characterized by muscle fatigability due to acetylcholine receptor (AChR) autoantibodies. To better characterize juvenile MG (JMG), we analyzed 85 pre- and 132 post-pubescent JMG (with a cutoff age of 13) compared to 721 adult MG patients under 40 years old using a French database. Clinical data, anti-AChR antibody titers, thymectomy, and thymic histology were analyzed. The proportion of females was higher in each subgroup. No significant difference in the anti-AChR titers was observed. Interestingly, the proportion of AChR+ MG patients was notably lower among adult MG patients aged between 30 and 40 years, at 69.7%, compared to over 82.4% in the other subgroups. Thymic histological data were examined in patients who underwent thymectomy during the year of MG onset. Notably, in pre-JMG, the percentage of thymectomized patients was significantly lower (32.9% compared to more than 42.5% in other subgroups), and the delay to thymectomy was twice as long. We found a positive correlation between anti-AChR antibodies and germinal center grade across patient categories. Additionally, only females, particularly post-JMG patients, exhibited the highest rates of lymphofollicular hyperplasia (95% of cases) and germinal center grade. These findings reveal distinct patterns in JMG patients, particularly regarding thymic follicular hyperplasia, which appears to be exacerbated in females after puberty.

Acetylcholinesterase inhibitors are ineffective in MuSK-antibody positive myasthenia gravis: Results of a study on 202 patients

BACKGROUND

Myasthenia gravis (MG) with MuSK antibodies (MuSK-MG) represents a distinct subtype with different responses to treatments compared to patients with AChR antibodies, especially in terms of tolerance to acetylcholinesterase inhibitors (AChEI). However, AChEI are often used as first line symptomatic treatment in MuSK-MG, despite reports that they are poorly tolerated, seldom effective or even deleterious.

METHODS

We analyzed demographic, clinical and therapeutic responses and side-effects in the large cohort of 202 MuSK-MG patients cared for at the MG Clinic of Azienda Ospedaliero-Universitaria Pisana.

RESULTS

165 patients had received AChEI at first evaluation. Only 7/165 patients (4.2%) reported an initial clinical benefit. Conversely, 76.9% of patients reported at least one side effect, most commonly neuromuscular hyperexcitability (68.4%), gastrointestinal (53.9%) and neurovegetative (35.8%) disturbances. 56 (33.9%) patients reported a concomitant worsening of muscle weakness and twelve patients (7.3%) suffered a cholinergic crisis. According to these patients, the severity of cholinergic side effects was greater at higher doses of AChEI, but side effects occurred regardless of the dose administered and ceased once the drug was discontinued.

CONCLUSIONS

This is the largest population of MuSK-MG patients reported for perceived responsiveness and tolerance to AChEI treatment. Our obervations strongly suggest avoiding this treatment in MuSK-MG.

Long-term prognosis in patients with thymoma combined with myasthenia gravis: a propensity score-matching analysis

Introduction

We aimed to assess the impact of myasthenia gravis (MG) on the long-term prognosis in patients with thymoma after surgery and identify related prognostic factors or predictors.

Methods

This retrospective observational study included 509 patients with thymoma (thymoma combined with MG [MG group] and thymoma alone [non-MG group]). Propensity score matching was performed to obtain comparable subsets of 96 patients in each group. A comparative analysis was conducted on various parameters.

Results

Before matching, the 10-year survival and recurrence-free survival rates in both groups were 93.8 and 98.4%, and 85.9 and 93.4%, respectively, with no statistically significant difference observed in the survival curves between the groups (p > 0.05). After propensity score matching, 96 matched pairs of patients from both groups were created. The 10-year survival and recurrence-free survival rates in these matched pairs were 96.9 and 97.7%, and 86.9 and 91.1%, respectively, with no statistical significance in the survival curves between the groups (p > 0.05). Univariate analysis of patients with thymoma postoperatively revealed that the World Health Organization histopathological classification, Masaoka-Koga stage, Tumor Node Metastasis stage, resection status, and postoperative adjuvant therapy were potentially associated with tumor recurrence after thymoma surgery. Multivariate analysis demonstrated that the Masaoka-Koga stage and postoperative adjuvant therapy independently predicted the risk of recurrence in patients with thymoma after surgery.

Conclusion

There was no difference in prognosis in patients with thymoma with or without MG. The Masaoka-Koga stage has emerged as an independent prognostic factor affecting recurrence-free survival in patients with thymoma, while postoperative adjuvant therapy represents a poor prognostic factor.

Making an accurate diagnosis of anterior mediastinal lesions: a proposal for a new diagnostic algorithm from the BTOG Thymic Malignancies Special Interest Group

Due to the rising demand in cross-sectional thoracic imaging, anterior mediastinal lesions are being identified with increasing frequency. Following iterative and multidisciplinary discussions, the BTOG Thymic Malignancies Special Interest Group have developed an algorithm to standardise the diagnostic approach for these relatively uncommon but important conditions which span from benign (thymic remnant, thymic hyperplasia and thymic cysts) to suspected localised thymomas to suspected more aggressive malignancy (thymic carcinoma, lymphoma and germ cell tumours). For each condition, we provide a brief description, an overview of the key radiological findings and a description of the proposed algorithm including the rationale behind the recommendations. We also highlight the role of magnetic resonance (MR) imaging for the characterisation of anterior mediastinal masses in specific indications when the necessary local resources and expertise exist. In addition, we hope this provides the rationale for service development in MR of the anterior mediastinum where current resource and expertise requires development. Through this standardised pathway, we hope to drive improvements in patient care by rationalising surveillance schedules, avoiding unnecessary resections of benign entities with their associated morbidity and optimising the diagnostic work-up prior to the appropriate treatment of anterior mediastinal malignancies.

Long-term follow-up of non-myasthenic patients with early-stage thymoma who underwent extended thymectomy or limited resection

BACKGROUD

The standard resection for early-stage thymoma is total thymectomy and complete tumour excision with or without myasthenia gravis but the optimal surgery mode for patients with early-stage non-myasthenic thymoma is debatable. This study analysed the oncological outcomes for non-myasthenic patients with early-stage thymoma treated by thymectomy or limited resection in the long term.

METHODS

Patients who had resections of thymic neoplasms at Taipei Veteran General Hospital, Taiwan between December 1997 and March 2013 were recruited, exclusive of those combined clinical evidence of myasthenia gravis were reviewed. A total of 113 patients were retrospectively reviewed with pathologic early stage (Masaoka stage I and II) thymoma who underwent limited resection or extended thymectomy to compare their long-term oncologic and surgical outcomes.

RESULTS

The median observation time was 134.1 months [interquartile range (IQR) 90.7-176.1 months]. In our cohort, 52 patients underwent extended thymectomy and 61 patients underwent limited resection. Shorter duration of surgery (p < 0.001) and length of stay (p = 0.006) were demonstrated in limited resection group. Six patients experienced thymoma recurrence, two of which had combined myasthenia gravis development after recurrence. There was no significant difference (p = 0.851) in freedom-from-recurrence, with similar 10-year freedom-from-recurrence rates between the limited resection group (96.2 %) and the thymectomy group (93.2 %). Tumour-related survival was also not significantly different between groups (p = 0.726).result CONCLUSION: Patients with early-stage non-myasthenic thymoma who underwent limited resection without complete excision of the thymus achieved similar oncologic outcomes during the long-term follow-up and better peri-operative results compared to those who underwent thymectomy.

The rate of QMGS change predicts recurrence after thymectomy in myasthenia gravis

OBJECTIVE

To investigate the relationship between short-term changes in quantitative myasthenia gravis score (QMGS) after thymectomy and postoperative recurrence in myasthenia gravis (MG) patients without thymoma.

METHODS

A retrospective observational cohort study. The QMGS of 44 patients with non-thymomatous MG were evaluated before and 1 month after thymectomy, and the frequency and time of postoperative recurrence were recorded. The reduction rate of QMGS (rr-QMGS) was defined as (QMGS one week before thymectomy - QMGS one month after thymectomy)/ QMGS one week before thymectomy × 100 %, as an indicator of short-term symptom change after thymectomy. The receiver operating characteristic (ROC) curve was established to determine an appropriate cut-off value of rr-QMGS for distinguishing postoperative recurrence. Multivariate Cox regression analysis was applied to predict postoperative recurrence.

RESULTS

Postoperative recurrence occurred in 21 patients (30 times in total) during follow-up. The mean annual recurrence rate was 3.98 times/year preoperatively and 0.30 times/year postoperatively. ROC analysis determined the cut-off value of rr-QMGS was 36.7 % (sensitivity 90.5 %, specificity 52.2 %). Multivariate Cox regression analysis showed that rr-QMGS＜36.7 % (hazard rate[HR]6.251, P = 0.014) is positive predictor of postoperative recurrence. Kaplan-Meier analysis showed that postoperative recurrence time was earlier in the low rr-QMGS group than in the high rr-QMGS group (12.62 vs. 36.60 months, p = 0.005).

CONCLUSIONS

Low rr-QMGS is associated with early postoperative recurrence. Rr-QMGS can be used to predict postoperative recurrence of non-thymomatous MG.

Physiological and pathological roles of the thymus and value of thymectomy in myasthenia gravis: a narrative review

Background and Objective

Myasthenia gravis (MG) is a well-elucidated autoimmune disorder affecting the neuromuscular junction. Given the relationship between MG and thymic pathologies, with T cell and antibody-mediated pathogenesis, surgical (i.e., thymectomy) and non-surgical approaches remain a mainstay of management of the disease. This review seeks to outline the involvement of the thymus in the development of lymphocytes leading to MG.

Methods

Different databases were searched exploring the role of thymectomy in treatment and outcomes in various MG patient subpopulations, including in ocular versus generalized disease, different age groups, and antibody status.

Key Content and Findings

Overall, the findings of multiple studies and reviews provide evidence to support the efficacy and long-term success of thymectomy in the management of MG; outcomes have included remission status, symptom severity, and need for adjunctive therapy. However, the heterogeneity in the MG population suggests that there are multiple factors that may confound the results of thymectomy and still need further examination. Separately, other autoimmune diseases develop following thymectomy, and further research is required to elucidate this susceptibility. Finally, our review will discuss the different surgical approaches for thymectomy, including their advantages, limitations, and perioperative complications.

Conclusions

Overall, in light of the known pathogenesis and association of the thymus with MG, thymectomy remains an extremely effective approach for long-term management and improved clinical outcomes.

Generalized myasthenia gravis with acetylcholine receptor antibodies: A guidance for treatment

BACKGROUND

Generalized myasthenia gravis (MG) with antibodies against the acetylcholine receptor is a chronic disease causing muscle weakness. Access to novel treatments warrants authoritative treatment recommendations. The Nordic countries have similar, comprehensive health systems, mandatory health registers, and extensive MG research.

METHODS

MG experts and patient representatives from the five Nordic countries formed a working group to prepare treatment guidance for MG based on a systematic literature search and consensus meetings.

RESULTS

Pyridostigmine represents the first-line symptomatic treatment, while ambenonium and beta adrenergic agonists are second-line options. Early thymectomy should be undertaken if a thymoma, and in non-thymoma patients up to the age of 50-65 years if not obtaining remission on symptomatic treatment. Most patients need immunosuppressive drug treatment. Combining corticosteroids at the lowest possible dose with azathioprine is recommended, rituximab being an alternative first-line option. Mycophenolate, methotrexate, and tacrolimus represent second-line immunosuppression. Plasma exchange and intravenous immunoglobulin are used for myasthenic crises and acute exacerbations. Novel complement inhibitors and FcRn blockers are effective and fast-acting treatments with promising safety profiles. Their use depends on local availability, refunding policies, and cost-benefit analyses. Adapted physical training is recommended. Planning of pregnancies with optimal treatment, information, and awareness of neonatal MG is necessary. Social support and adaptation of work and daily life activities are recommended.

CONCLUSIONS

Successful treatment of MG rests on timely combination of different interventions. Due to spontaneous disease fluctuations, comorbidities, and changes in life conditions, regular long-term specialized follow-up is needed. Most patients do reasonably well but there is room for further improvement. Novel treatments are promising, though subject to restricted access due to costs.

Summary of the best evidence for the prevention and management of myasthenic crisis after thymectomy

Background

Myasthenic crisis (MC) may occur after thymectomy in patients with myasthenia gravis (MG), but effective preventive interventions can reduce the occurrence of this complication. Previous research on MC focused on risk factors, emergency treatment, etc., which was relatively scattered and did not form a comprehensive management framework. This study sought to retrieve and summarize the relevant evidence on the prevention and management of postoperative MC to provide a theoretical reference for clinical medical staff.

Methods

According to the evidence pyramid model, relevant articles were retrieved from UpToDate, British Medical Journal (BMJ) Best Practice, World Health Organization (WHO), Scottish Intercollegiate Guidelines Network (SIGN), Guidelines International Network (GIN), Australian Joanna Briggs Institute (JBI) Healthcare Database, Medlive, PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang. The types of evidence included clinical guidelines, expert consensus articles, clinical decisions, systematic reviews, and randomized controlled trials (RCTs). The quality evaluations were conducted using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) evaluation tool for guidelines, the Australian JBI Evidence-Based Healthcare Center evaluation tool for expert consensus articles, the Critical Appraisal for Summaries of Evidence (CASE) evaluation tool for clinical decisions, the Assessment of Multiple Systematic Reviews (AMSTAR) evaluation tool for systematic reviews, and the Cochrane risk-of-bias tool for RCTs.

Results

A total of 12 articles were included in this study, including three clinical guidelines, three expert consensus articles, three clinical decisions, two systematic reviews, and one RCT. From these articles, we summarized 39 pieces of evidence on the prevention and management of postoperative MC.

Conclusions

This study summarized the best evidence on the prevention and management of postoperative MC and provided to clinical staffs evidence-based clinical approaches to help reduce the incidence of this complication.

Systemic Inflammatory Response Index, a Potential Inflammatory Biomarker in Disease Severity of Myasthenia Gravis: A Pilot Retrospective Study

Purpose

Myasthenia gravis (MG) is a chronic autoimmune disease caused by neuromuscular junction (NMJ) dysfunction. Our current understanding of MG's inflammatory component remains poor. The systemic inflammatory response index (SIRI) presents a promising yet unexplored biomarker for assessing MG severity. This study aimed to investigate the potential relationship between SIRI and MG disease severity.

Patients and Methods

We conducted a retrospective analysis of clinical data from 171 MG patients admitted between January 2016 and June 2021. Patients with incomplete data, other autoimmune diseases, or comorbidities were excluded. Disease severity was evaluated using the Myasthenia Gravis Foundation of America (MGFA) classification and Myasthenia Gravis Activities of Daily Living (MG-ADL) on admission. The association between SIRI and disease severity was assessed through logistic regression analysis, along with receiver operating characteristic (ROC) curve and decision curve analysis (DCA) comparisons with established inflammation indicators.

Results

After exclusion, 143 patients were analyzed in our study. SIRI levels significantly differed between patients with higher and lower disease severity (p < 0.001). Univariate logistic regression showed that SIRI had a significant effect on high disease severity (OR = 1.376, 95% CI 1.138-1.664, p = 0.001). This association remained significant even after adjusting for age, sex, disease duration, history of MG medication and thymoma (OR = 1.308, 95% CI 1.072-1.597, p = 0.008). Additionally, a positive correlation between SIRI and MG-ADL was observed (r = 0.232, p = 0.008). Significant interactions were observed between SIRI and immunosuppressor (p interaction = 0.001) and intravenous immunoglobulin (p interaction = 0.005). DCA demonstrated the superior net clinical benefit of SIRI compared to other markers when the threshold probability was around 0.2.

Conclusion

Our findings indicate a strong independent association between SIRI and disease severity in MG, suggesting SIRI's potential as a valuable biomarker for MG with superior clinical benefit to currently utilized markers.

[Myasthenia Gravis - Update]

Myasthenia gravis - still a challenge for sufferers and doctors in 2023. But which therapy is best suited? Our clinically experienced experts have summarized the current guidelines for diagnosis and treatment in order to provide optimal support for those affected. Find out how you can carry out a quick and targeted diagnosis and which treatment options are available to alleviate the course of the disease.

Thymectomy for juvenile myasthenia gravis: a narrative review

Background and Objective

Thymectomy as a management strategy for juvenile myasthenia gravis (JMG) has been increasingly adopted with the advent of minimally invasive surgical techniques. This review evaluates existing evidence regarding the surgical management of JMG, including the benefits of surgical compared to medical therapy, important considerations when evaluating surgical candidacy and determining optimal timing of intervention. In addition, we provide an overview of the open, thoracoscopic and robotic surgical approaches available for thymectomy and compare the existing data to characterize optimal surgical management.

Methods

A thorough literature review was conducted for full length research articles, including systematic reviews, retrospective cohort studies and case series, published between January 2000 and July 2023 regarding open, thoracoscopic or robotic thymectomy for management of JMG. Reference lists of the identified articles were manually searched for additional studies. Evidence was summarized in a narrative fashion with the incorporation of the authors' knowledge gained through clinical experience.

Key Content and Findings

Although data specific to JMG are limited to small retrospective cohort studies, available evidence supports equal to greater disease control following thymectomy versus pharmacologic management. Furthermore, outcomes may be optimized when surgery is performed earlier in the disease course, particularly for patients who are post-pubertal with generalized or severe disease and those necessitating high-dose steroid administration thereby limiting its metabolic and growth inhibitory effects. Open transsternal resection is the historic gold-standard; however, as surgeons become more comfortable with thoracoscopic and robotic-assisted thymectomy, an increasing proportion of patients are expected to undergo thymectomy. At present, the data available is unable to support conclusions regarding which surgical approach is superior; however, minimally invasive approaches may be non-inferior while offering superior cosmesis and decreased morbidity.

Conclusions

Higher-level investigation through the use of multi-institutional databases and randomized prospective trials is warranted in order to understand which child warrants thymectomy, at what point in their disease course and their development, and which surgical approach will optimize postoperative outcomes.

An angel or a devil? Current view on the role of CD8+ T cells in the pathogenesis of myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) and the experimental autoimmune MG (EAMG) animal model are characterized by T-cell-induced and B-cell-dominated autoimmune diseases that affect the neuromuscular junction. Several subtypes of CD4+ T cells, including T helper (Th) 17 cells, follicular Th cells, and regulatory T cells (Tregs), contribute to the pathogenesis of MG. However, increasing evidence suggests that CD8+ T cells also play a critical role in the pathogenesis and treatment of MG.

MAIN BODY

Herein, we review the literature on CD8+ T cells in MG, focusing on their potential effector and regulatory roles, as well as on relevant evidence (peripheral, in situ, cerebrospinal fluid, and under different treatments), T-cell receptor usage, cytokine and chemokine expression, cell marker expression, and Treg, Tc17, CD3+CD8+CD20+ T, and CXCR5+ CD8+ T cells.

CONCLUSIONS

Further studies on CD8+ T cells in MG are necessary to determine, among others, the real pattern of the Vβ gene usage of autoantigen-specific CD8+ cells in patients with MG, real images of the physiology and function of autoantigen-specific CD8+ cells from MG/EAMG, and the subset of autoantigen-specific CD8+ cells (Tc1, Tc17, and IL-17+IFN-γ+CD8+ T cells). There are many reports of CD20-expressing T (or CD20 + T) and CXCR5+ CD8 T cells on autoimmune diseases, especially on multiple sclerosis and rheumatoid arthritis. Unfortunately, up to now, there has been no report on these T cells on MG, which might be a good direction for future studies.

Thymoma-associated autoimmune encephalitis with myasthenia gravis: Case series and literature review

OBJECTIVES

This comprehensive review aimed to compile cases of patients with thymoma diagnosed with both autoimmune encephalitis (AE) and myasthenia gravis (MG), and describe their clinical characteristics.

METHODS

Clinical records of 3 AE patients in the first affiliated hospital of Sun Yat-sen University were reviewed. All of them were diagnosed with AE between 1 November 2021 and 1 March 2022, and clinical evidence about thymoma and MG was found. All published case reports were searched for comprehensive literature from January 1990 to June 2022.

RESULTS

A total of 18 cases diagnosed with thymoma-associated autoimmune encephalitis (TAAE) and thymoma-associated myasthenia gravis (TAMG) were included in this complication, wherein 3 cases were in the first affiliated hospital of Sun Yat-sen University and the other 15 were published case reports. 5/18 patients had alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antibody (AMPAR-Ab) in their serum and cerebrospinal fluid (CSF). All of them had positive anti-acetylcholine receptor antibody (AChR-Ab). And 12/18 patients showed a positive response to thymectomy and immunotherapy. Besides, thymoma recurrences were detected because of AE onset. And the shortest interval between operation and AE onset was 2 years in patients with thymoma recurrence.

CONCLUSIONS

There was no significant difference in the clinical manifestations between these patients and others with only TAMG or TAAE. TAAE was commonly associated with AMPAR2-Ab. Significantly, AE more commonly heralded thymoma recurrences than MG onset. And the intervals of thymectomy and MG or AE onset had different meanings for thymoma recurrence and prognoses of patients.

Thymoma negatively affects the neurological outcome of myasthenia gravis after thymectomy: a propensity score matching study

BACKGROUND

Thymoma and myasthenia gravis (MG) interact with each other. This study aimed to evaluate the effects of thymoma on neurological outcome of MG patients after thymectomy using the propensity score matching (PSM) method.

METHODS

Consecutive patients with MG who underwent thymectomy at Beijing Hospital between January 2012 and August 2021 were retrospectively enrolled. Clinical and follow-up data were collected. Statistical analysis was performed using SPSS 23.0 software. PSM was performed to eliminate selection bias.

RESULTS

A total of 456 patients were included in this study. Thymoma was present in 138 (30.3%) patients. The median follow-up time was 72 (range, 12-135) months. At the last follow-up, a lower proportion of thymomatous MG patients achieved complete stable remission (CSR) compared with non-thymomatous MG patients (P = 0.011), and the effective rate [CSR + pharmatologic remission (PR) + minimal manifestations (MM)] of thymomatous MG patients was also lower (P = 0.037). Considering time to CSR, Kaplan-Meier analysis showed thymomatous MG patients had lower cumulative CSR rate than non-thymomatous MG patients (log-rank, P = 0.019). After PSM, 105 pairs of patients were matched successfully. For the matched patients, thymomatous MG patients had a lower CSR rate and a lower effective rate (P = 0.002, 0.039, respectively), and K-M analysis still showed thymomatous MG patients had lower cumulative CSR rate (log-rank, P = 0.048). Multivariate Cox analysis demonstrated that thymoma (HR: 0.592, 95% CI 0.389-0.900, P = 0.014), older age at the time of surgery (HR: 0.971, 95% CI 0.953-0.990, P = 0.003), and preoperative course of MG > 12 months (HR: 0.474, 95% CI 0.317-0.708, P = 0.000) were negative predictive factors for CSR.

CONCLUSIONS

Thymoma had a negative effect on the neurological outcome of MG after thymectomy. MG patients with old age and a preoperative course of longer than one year had a lower probability of achieving CSR.

The Clinical Course and Treatment of a Case of Refractory Systemic Juvenile Myasthenia Gravis Successfully Treated with Thymectomy

Juvenile myasthenia gravis (JMG) exhibits a more favorable response to glucocorticoids and has a better prognosis than adult myasthenia gravis. However, no established treatment exists for refractory JMG. Although thymectomy has been performed in several patients with refractory systemic JMG, there are few detailed clinical descriptions of patients who underwent thymectomy. Here, we present the case of a 10-year-old boy with refractory systemic JMG who was successfully treated with thymectomy. The patient developed symptoms, including dysphagia, malaise, diurnal ptosis, and weakness in the trunk muscles, and he was diagnosed with generalized JMG. Despite undergoing various treatments, including steroids, tacrolimus, steroid pulse therapy, intravenous immunoglobulin, azathioprine (AZT), and rituximab, his symptoms did not improve. Therefore, he underwent a thoracoscopic thymectomy 24 months after disease onset. Thymectomy led to remission, as demonstrated by a significant reduction in the quantitative myasthenia gravis score and anti-acetylcholine receptor antibody levels, which persisted for 43 months after surgery. Our case demonstrates the effectiveness of thymectomy in systemic JMG patients with positive anti-acetylcholine receptor antibodies, despite therapeutic failure with AZT and rituximab, within 2 years of disease onset.

High indirect bilirubin levels as an independent predictor of postoperative myasthenic crisis: a single-center, retrospective study

Background

Thymectomy is an efficient and standard treatment strategy for patients with myasthenia gravis (MG), postoperative myasthenic crisis (POMC) is the major complication related to thymectomy and has a strongly life-threatening effect. As a biomarker, whether the bilirubin level is a risk factor for MG progression remains unclear. This study aimed to investigate the association between the preoperative bilirubin level and postoperative myasthenic crisis (POMC).

Methods

We analyzed 375 patients with MG who underwent thymectomy at Tangdu Hospital between January 2012 and September 2021. The primary outcome measurement was POMC. The association between POMC and bilirubin level was analyzed by restricted cubic spline (RCS). Indirect bilirubin (IBIL) was divided into two subgroups based on the normal upper limit of IBIL, 14 μmol/L.

Results

Compared with non-POMC group, IBIL levels were significantly higher in patients with POMC. Elevated IBIL levels were closely associated with an increased risk of POMC (p for trend = 0.002). There was a dose-response curve relationship between IBIL levels and POMC incidence (p for non-linearity = 0.93). However, DBIL levels showed a U-shaped association with POMC incidence. High IBIL level (≥14 μmol/L) was an independent predictive factor for POMC [odds ratio = 3.47, 95% confidence interval (CI): 1.56-7.8, p = 0.002]. The addition of high IBIL levels improved the prediction model performance (net reclassification index = 0.186, 95% CI: 0.039-0.334; integrated discrimination improvement = 0.0345, 95% CI: 0.005-0.065).

Conclusion

High preoperative IBIL levels, especially those exceeding the normal upper limit, could independently predict the incidence of POMC.

[Ocular myasthenia gravis]

Myasthenia gravis is an autoimmune disease characterized by muscle weakness and pathological fatigue due to autoaggressive phenomena with the formation of antibodies directed against various structures of the neuromuscular synapse. In most patients, the disease begins with the involvement of extraocular muscles, presenting with symptoms such as intermittent ptosis of the upper eyelid and/or binocular diplopia. In 15% of cases, clinical manifestations are limited to impairment of the levator palpebrae superioris and extraocular muscles, characteristic of the ocular form of myasthenia gravis. Specialists often encounter challenges in diagnosing this form, as serological and electrophysiological studies may be uninformative, necessitating diagnosis based on patient history and clinical picture. This literature review outlines the key aspects of the pathogenesis, clinical manifestations, methods of diagnosis and treatment of ocular myasthenia gravis.

Mapping current trends and hotspots in myasthenia gravis from 2003 to 2022: a bibliometric analysis

Introduction

Research on myasthenia gravis (MG) has undergone rapid development in recent years. This article aimed to elucidate the characteristics of MG publications over the past 20 years and analyze emerging trends using bibliometric methods.

Methods

Information on MG articles was obtained from the Web of Science Core Collection and stored in Excel for quantitative analyses. Bibliometric analyses were performed using CiteSpace and VOSviewer to visualize publications according to countries/regions, institutions, journals, and authors.

Results

A total of 3,610 publications were included in the analysis. The USA had the highest number of publications (NP) and H-index. Among the institutions, the University of Oxford had the highest NP, followed by the University of Toronto and Duke University. Close cooperation was observed among countries and institutions. The most productive author was Renato Mantegazza, followed by Jan J. Verschuuren, and Amelia Evoli. Muscle & Nerve published the most articles on MG, followed by the Journal of Neuroimmunology and Neuromuscular Disorders. The keyword with the highest strength is "neuromuscular transmission," followed by "safety" and "rituximab." Co-citation analysis includes 103 publications cited at least 65 times, categorized into four clusters. Additionally, 123 keywords cited more than 40 times were analyzed and divided into five clusters.

Conclusion

This bibliometric analysis shows the framework of research over the past 20 years by mapping the scholarly contributions of various countries or regions, institutions, journals, and authors in MG. The analysis also explores future trends and prospective directions, emphasizing individualized treatment based on subtypes, novel immunotherapeutic approaches, and thymectomy.

Guideline for the management of myasthenic syndromes

Myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS), and congenital myasthenic syndromes (CMS) represent an etiologically heterogeneous group of (very) rare chronic diseases. MG and LEMS have an autoimmune-mediated etiology, while CMS are genetic disorders. A (strain dependent) muscle weakness due to neuromuscular transmission disorder is a common feature. Generalized MG requires increasingly differentiated therapeutic strategies that consider the enormous therapeutic developments of recent years. To include the newest therapy recommendations, a comprehensive update of the available German-language guideline 'Diagnostics and therapy of myasthenic syndromes' has been published by the German Neurological society with the aid of an interdisciplinary expert panel. This paper is an adapted translation of the updated and partly newly developed treatment guideline. It defines the rapid achievement of complete disease control in myasthenic patients as a central treatment goal. The use of standard therapies, as well as modern immunotherapeutics, is subject to a staged regimen that takes into account autoantibody status and disease activity. With the advent of modern, fast-acting immunomodulators, disease activity assessment has become pivotal and requires evaluation of the clinical course, including severity and required therapies. Applying MG-specific scores and classifications such as Myasthenia Gravis Activities of Daily Living, Quantitative Myasthenia Gravis, and Myasthenia Gravis Foundation of America allows differentiation between mild/moderate and (highly) active (including refractory) disease. Therapy decisions must consider age, thymic pathology, antibody status, and disease activity. Glucocorticosteroids and the classical immunosuppressants (primarily azathioprine) are the basic immunotherapeutics to treat mild/moderate to (highly) active generalized MG/young MG and ocular MG. Thymectomy is indicated as a treatment for thymoma-associated MG and generalized MG with acetylcholine receptor antibody (AChR-Ab)-positive status. In (highly) active generalized MG, complement inhibitors (currently eculizumab and ravulizumab) or neonatal Fc receptor modulators (currently efgartigimod) are recommended for AChR-Ab-positive status and rituximab for muscle-specific receptor tyrosine kinase (MuSK)-Ab-positive status. Specific treatment for myasthenic crises requires plasmapheresis, immunoadsorption, or IVIG. Specific aspects of ocular, juvenile, and congenital myasthenia are highlighted. The guideline will be further developed based on new study results for other immunomodulators and biomarkers that aid the accurate measurement of disease activity.

Adverse cognitive effects of glucocorticoids: A systematic review of the literature

OBJECTIVES

Glucocorticoids as a drug class are widely used in the treatment of many conditions including more recently as one of the mainstay treatments for the SARS-CoV-2 infection. The physiological adverse effects are well described. However, less is known and understood about the potentially deleterious neuro-cognitive effects of this class of medication.

METHODS

We carried out a systematic review of the literature using two separate search strategies. The first focussed on the rates of reporting of adverse cognitive effects of glucocorticoid use in randomised controlled trials. The second looked at those studies focussing directly on adverse cognitive effects associated with the use of glucocorticoids. MEDLINE, Embase and Cochrane Library was searched for randomised controlled trials utilising glucocorticoids as a part of a treatment regimen. Additionally, these databases were also used to search for articles looking directly at the adverse cognitive effects of glucocorticoids.

RESULTS

Of the forty-three RCTs included as a part of the first search strategy, only one (2.3%) included specific documentation pertaining to cognitive side effects. As a part of the twenty studies included in the second search strategy, eleven of the included studies (55%) were able to demonstrate a correlation between glucocorticoid use and decreased cognition. Most studies within this strategy showed that GCs predominately affected hippocampus-dependent functions such as memory, while sparing executive function and attention.

CONCLUSIONS

Overall, the data reporting of adverse clinical effects of glucocorticoid use is poor in recent RCTs. Given the demonstrable effect on predominately hippocampal-dependent cognitive functions evident within the literature, more thorough documentation is needed within clinical research to fully appreciate the potentially widespread nature of these effects.

Paraneoplastic Neurologic Syndromes

OBJECTIVE

Progress is ongoing in understanding paraneoplastic neurologic disorders, with new syndromes and antibodies being described and more detailed evidence available to guide workup for diagnosis and treatment to improve outcomes. Many excellent reviews have summarized the molecular features of different antibodies, but this article emphasizes the clinical features of each syndrome that may help guide initial diagnosis and treatment, which often should occur before an antibody or cancer is found to confirm the diagnosis.

LATEST DEVELOPMENTS

Recent findings include updated diagnostic criteria with validated sensitivity and specificity, discovery of novel antibodies, and clinical findings that increase the likelihood of an underlying paraneoplastic disorder. Suggestive syndromes that have been recently identified include faciobrachial dystonic seizures and pilomotor auras in anti-leucine-rich glioma inactivated protein 1 encephalitis, extreme delta brush on EEG in N-methyl-d-aspartate (NMDA)-receptor encephalitis, déjà vu aura in anti-glutamic acid decarboxylase 65 (GAD65) encephalitis, and sleep disturbances in several disorders. In addition, there is confirmed utility of brain positron emission tomography (PET) and CSF markers, including carcinoembryonic antigen and oligoclonal bands, as well as improved tests for the presence of leptomeningeal cancer cells in CSF. Associations of cancer immunotherapies with paraneoplastic syndromes and herpes simplex virus encephalitis (and COVID-19) with NMDA-receptor encephalitis have been described.

ESSENTIAL POINTS

All neurologists should be aware of advances regarding paraneoplastic neurologic syndromes, as patients can present with a wide variety of neurologic symptoms and earlier diagnosis and treatment can improve outcomes.

Combined effect of thymectomy on myasthenia gravis in patients with concomitant auto-immune diseases: a 22-year single-center experience

Myasthenia gravis (MG) is an autoimmune disease (AD), and patients with MG often have other types of ADs. We analyzed the prognosis of patients with MG complicated by AD after thymectomy. A retrospective analysis was performed for patients with MG complicated by ADs treated surgically in our center over the past 22 years, and their general condition and follow-up data were collected and analyzed. 33 patients were included totally. 28 patients displayed improvement or even complete recovery of MG, and 23 of 36 ADs revealed improvement or even complete recovery. The prognosis of MG is significantly correlated with the duration of postoperative follow-up time (p = 0.028), and in patients with thymoma, the larger the tumor diameter, the better the prognosis of MG (p = 0.026). Thymic hyperplasia patients were predominantly female (p = 0.049) and young (p < 0.001). The most common concomitant AD in this study was a thyroid-associated AD, which was associated with thymic hyperplasia (p < 0.001), Osserman type I MG (p < 0.001), and young age (p < 0.001). Thymectomy had a good therapeutic effect on MG complicated by AD, and there was a close correlation between surgery, thymus, MG, and ADs.

Circulating miRNAs drive personalized medicine based on subgroup classification in myasthenia gravis patients

Myasthenia gravis (MG) is a classic autoimmune neuromuscular disease with strong clinical heterogeneity. The concept of subgroup classification was proposed to guide the precise treatment of MG. Subgroups based on serum antibodies and clinical features include ocular MG, early-onset MG with AchR antibodies, late-onset MG with AchR antibodies, thymoma-associated MG, MuSK-associated MG, LRP4-associated MG, and seronegative MG. However, reliable objective biomarkers are still needed to reflect the individualized response to therapy. MicroRNAs (miRNAs) are small non-coding RNA molecules which can specifically bind to target genes and regulate gene expression at the post-transcriptional level, and then influence celluar biological processes. MiRNAs play an important role in the pathogenesis of autoimmune diseases, including MG. Several studies on circulating miRNAs in MG have been reported. However, there is rare systematic review to summarize the differences of these miRNAs in different subgroups of MG. Here, we summarize the potential role of circulating miRNAs in different subgroups of MG to promote personalized medicine.

Impact of Ravulizumab on Patient Outcomes and Quality of Life in Generalized Myasthenia Gravis

Myasthenia gravis (MG) is an autoimmune ion channel disorder in which antibodies to different end-plate antigens impair neuromuscular transmission, ultimately leading to muscle weakness and fatigability. In about 85% of patients with MG, autoantibodies against the acetylcholine receptor (AChR) activate the complement cascade, causing damage to the neuromuscular junction. MG is a chronic disorder for which standard therapies with corticosteroids, immunosuppressive drugs, and immunomodulation with plasma exchange or intravenous immunoglobulins modify the course of the disease, but the residual burden of physical, psychological, and social disability highlights several unmet needs, among these the need for specific, targeted, and well tolerated therapies able to improve the patients' quality of life. Complement inhibition paved the way to precision medicine in MG since, for the first time, a specific therapy targeting a crucial pathogenetic step has been designed, tested, and proven to be effective in a controlled fashion. Ravulizumab represents the first long-acting complement inhibitor approved for treatment of patients with generalized MG, able to provide rapid, complete, and sustained complement inhibition. Ravulizumab improved the MG Activity of Daily Living scale and other clinical parameters up to 26 weeks as shown by the CHAMPION MG trial, and by its open label extension, with the added value of being administered every 8 weeks. The schedule of administration is likely to improve patients' adherence and hence their quality of life. The introduction of complement inhibition will considerably change the traditional therapeutic strategy for MG.

Disease-Based Prognostication: Myasthenia Gravis

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.

Thymectomy in myasthenia gravis

PURPOSE OF REVIEW

Thymectomy has long been used in the treatment of patients with myasthenia gravis and antibodies against the acetylcholine receptor. However, its effectiveness has only been proven a few years ago in a randomized controlled trial in patients under the age of 65. Here, we review the current literature focusing on patient subgroups, potential biomarkers for outcome prediction and the choice of surgical approach.

RECENT FINDINGS

Long-term follow-up studies after thymectomy confirmed that the benefits regarding clinical outcome parameters and a reduced need for immunosuppressive treatment persist. Nevertheless, a substantial proportion of patients in real-world cohorts do not reach complete stable remission after thymectomy indicating that the underlying autoimmune process is sustained in the periphery. Our understanding of the responsible mechanisms has improved with recent studies. Presently, outcome data after thymectomy in several patient subgroups, such as those aged over 50 years, those with juvenile onset or those with purely ocular symptoms are limited and have been the focus of recent research activities. Similarly, biomarkers guiding an appropriate patient selection for thymectomy are under investigation. A number of cohort studies demonstrated that minimal invasive surgical techniques such as extended robotic thymectomy lead to similar positive outcomes as a transsternal approach with potentially fewer short-term adverse effects.

SUMMARY

Thymectomy is an effective treatment option in adult patients with early onset acetylcholine-receptor positive myasthenia gravis but uncertainty remains with regard to certain patient subgroups.

A multicentre, prospective, double-blind study comparing the accuracy of autoantibody diagnostic assays in myasthenia gravis: the SCREAM study

BACKGROUND

Laboratory determination of autoantibodies against acetylcholine receptor (AChR), muscle-specific kinase (MuSK) and other autoantigens have been integrated into the diagnosis of myasthenia gravis (MG). However, evidence supporting the selection of methodologies is lacking.

METHODS

In this prospective, multicentre cohort study, we recruited patients with suspected MG to evaluate the diagnostic accuracy of cell-based assay (CBA), radioimmunoprecipitation assay (RIPA) and enzyme-linked immunosorbent assay (ELISA) in detecting AChR and MuSK autoantibodies. This study is registered with www.clinicaltrials.gov, number NCT05219097.

FINDINGS

2272 eligible participants were recruited, including 2043 MG, 229 non-MG subjects. AChR antibodies were detected in 1478, 1310, and 1280 out of a total of 2043 MG patients by CBA, RIPA, and ELISA, respectively; sensitivity, 72.3% (95% CI, 70.3-74.3), 64.1% (95% CI, 62.0-66.2), 62.7% (95% CI, 60.5-64.8); specificity, 97.8% (95% CI, 95.0-99.3), 97.8% (95% CI, 95.0-99.3), 94.8% (95% CI, 91.9-97.7). MuSK antibodies were found in 59, 50, and 54 from 2043 MG patients by CBA, RIPA and ELISA, respectively; sensitivity, 2.9% (95% CI, 2.2-3.7), 2.4% (95% CI, 1.8-3.2), 2.6% (95% CI, 2.0-3.4); specificity, 100% (95% CI, 98.4-100), 100% (95% CI, 98.4-100), and 99.1% (95% CI, 96.9-99.9). The area under the curve of AChR antibodies tested by CBA was 0.858, and there were statistical differences with RIPA (0.843; p = 0.03) and ELISA (0.809; p < 0.0001).

INTERPRETATION

CBA has a higher diagnostic accuracy compared to RIPA or ELISA in detecting AChR and MuSK autoantibodies for MG diagnosis.

FUNDING

New Terrain Biotechnology, Inc., Tianjin, China.

[Robot-assisted Mediastinal Surgery]

Because of the many important anatomical structures located closely together at very small distances, mediastinal surgery has been traditionally demanding and challenging within thoracic surgery. With their great variability, mediastinal masses in the anterior, middle or posterior mediastinal compartment result in surgical indications with different principle focuses. The technical opportunities of robotic assistance can thereby most effectively support the requirement of precision for all oncological aspects. Anterior mediastinal operations are most often performed, thymectomy being the most common operation. The radicality of thymectomy is of special importance. The worldwide tremendous development of robot-assisted mediastinal surgery confirms its initial and continuous role as a pacemaker for minimally invasive thoracic surgery.

A skewed ratio of free light chains is more common in patients with late-onset than early-onset myasthenia gravis

Myasthenia gravis (MG) is an autoantibody-mediated neuromuscular disease with an unpredictable clinical course. Serum free light chains (FLCs) have risen as a promising biomarker for MG, but their role in different subtypes of MG and in predicting disease progression is still uncharted. We investigated plasma from 58 generalized MG patients during post-thymectomy follow-up to determine κ and λ FLC and κ/λ ratio. In a subcohort of 30 patients, we examined the expression of 92 proteins associated with immuno-oncology using Olink. We further studied the ability of FLCs or proteomic markers to differentiate disease severity. Patients with late-onset MG (LOMG) displayed significantly higher mean κ/λ ratio than patients with early-onset MG (P=0.004). Inducible T-cell co-stimulator ligand (ICOSLG), matrix metalloproteinase 7 (MMP7), hepatocyte growth factor (HGF), and arginase 1 (ARG1) were differentially expressed in MG patients compared to healthy controls. There were no significant associations between clinical outcomes and FLCs or the assayed proteins. In conclusion, an elevated κ/λ ratio suggests long-lasting aberrant clonal plasma cell function in LOMG. Immuno-oncology-related proteomic analysis showed alterations in immunoregulatory pathways. Our findings pinpoint the FLC ratio as a biomarker for LOMG and call for further investigation of the immunoregulatory pathways in MG.

Novel Immunotherapies for Myasthenia Gravis

Myasthenia gravis (MG), a prototype autoimmune neurological disease, had its therapy centred on corticosteroids, non-steroidal broad-spectrum immunotherapy and cholinesterase inhibitors for several decades. Treatment-refractory MG and long-term toxicities of the medications have been major concerns with the conventional therapies. Advances in the immunology and pathogenesis of MG have ushered in an era of newer therapies which are more specific and efficacious. Complement inhibitors and neonatal Fc receptor blockers target disease-specific pathogenic mechanisms linked to myasthenia and have proven their efficacy in pivotal clinical studies. B cell-depleting agents, specifically rituximab, have also emerged as useful for the treatment of severe MG. Many more biologicals are in the pipeline and in diverse stages of development. This review discusses the evidence for the novel therapies and the specific issues related to their clinical use.

Effect of Thymectomy on Outcomes of Myasthenia Gravis Patients: A Case-Control Study at a Tertiary Care Hospital

Background and objective Myasthenia gravis (MG) is an acquired autoimmune disease mediated by antibodies affecting the neuro-muscular junction on the postsynaptic membrane, resulting in neuromuscular transmission obstruction and, consequently, muscle weakening. It is believed that the thymus gland plays a critical role in the production of these antibodies. Screening patients for thymoma and surgical excision of the thymus gland is a crucial part of the treatment. To compare the odds of good outcomes in Myasthenia Gravis patients with or without thymectomy. Material and methods A retrospective case-control study was conducted at the Department of Medicine and Neurology, Ayub Teaching Hospital, Abbottabad, Pakistan, from October 2020 to September 2021. A purposive sampling technique was employed. Thirty-two MG patients with thymectomy and 64 MG patients without thymectomy were selected for investigation. Controls and cases were matched on the basis of sex and age (1:2). A positive EMG study, acetylcholine receptor antibodies, and a pyridostigmine test were used to make the diagnosis of MG. Patients were called to the outpatient department for assessment of treatment outcomes. Primary outcome evaluation was done using the Myasthenia Gravis Foundation of America Post-Intervention Status (MGFA-PIS) tool at the last follow-up after one year. Results A sample of 96 patients was evaluated, of which 63 (65%) were females and 33 (34%) were males. The mean age for Group 1 (cases) was 35 years ±8.9 and for Group 2 (controls) was 37± 11.1. Age and Osserman stages were shown to be the two most crucial prognostic factors in our study. However, there are several other factors in our study that are linked to a poor response, such as a greater BMI, dysphagia, thymoma, older age, and a longer duration of disease. Conclusions Our findings indicate that none of the analysed groups had significantly worse outcomes as a result of the current clinical practice of thymectomy patient selection.

Ravulizumab for the treatment of myasthenia gravis

INTRODUCTION

Myasthenia gravis (MG) is a neurological B-cell mediated autoimmune disorder affecting the neuromuscular junction. MG therapeutics have always relied on nonselective immunosuppression with oral steroids and non-steroidal immunosuppressants, mainly with good clinical response. However, clinical stabilization is often reached at the cost of many troublesome side effects and up to 15% of MG patients are deemed as refractory to conventional immunosuppression. This highlights the need of a more targeted and efficacious therapeutic approach. Results from the randomized-controlled period of the CHAMPION study demonstrate a good safety, tolerability, and efficacy profile of ravulizumab compared to placebo. Like eculizumab, ravulizumab is an anti-C5 monoclonal antibody, but with an enhanced pharmacokinetic profile, that allows dosing every 8 weeks.

AREAS COVERED

We provide an overview of ravulizumab biological features and results from the phase III CHAMPION MG (NCT03920293) study.

EXPERT OPINION

Data of the CHAMPION MG trial demonstrate that ravulizumab is effective and safe in the treatment of generalized MG. Having a rapid clinical effect, with long-term clinical response, ravulizumab could represent a selective immunosuppressive drug of choice in the future therapeutic algorithm of MG, where conventional immunosuppressants slowly leave room for newer drugs with a more targeted mechanism of action.

Surgical safety analysis and clinical experience sharing of myasthenia gravis patients aged 65 and over

BACKGROUND

To evaluate the surgical safety in myasthenia gravis (MG) patients aged 65 and over.

METHODS

A total of 564 patients with MG who underwent surgery in the Department of Thoracic Surgery of Beijing Hospital from November 2011 to March 2022 were included in the study and divided into two groups taking the age of 65 as the boundary. Perioperative data of patients were recorded and statistically analyzed.

RESULTS

Compared with young patients, FEV1, FEV1% and MVV in lung function of elderly MG patients were worse (p < 0.001, p < 0.001, p = 0.002). Postoperative drainage time was longer (p < 0.001), combined with more drainage volume (p = 0.002). The American Society of Anesthesiologists (ASA) score of elderly MG patients was higher (p < 0.001). Complications were more likely to occur (p = 0.008) after surgery and Clavien-Dindo classification (CDC) of postoperative complications was also higher (p = 0.003). Meanwhile, postoperative myasthenic crisis (POMC) was more likely to occur (p = 0.038). Logistic regression showed that lower DLCO% (p = 0.049) was an independent risk factor for postoperative complications.

CONCLUSIONS

Surgical indications should be considered in each elderly MG patient on an individual basis. Moreover, most elderly MG patients safely survive the perioperative period and benefit from surgery through individualized consideration.

Risk factors for postoperative myasthenia gravis in patients with thymoma without myasthenia gravis: A systematic review and meta-analysis

Introduction

According to the principle, thymomas combined with myasthenia gravis (MG) require surgical treatment. However, patients with non-MG thymoma rarely develop MG and early- or late-onset MG after surgery is called postoperative MG (PMG). Our study used a meta-analysis to examine the incidence of PMG and risk factors.

Methods

Relevant studies were searched for in the PubMed, EMBASE, Web of Science, CNKI,and Wanfang databases. Investigations that directly or indirectly analyzed the risk factors for PMG development in patients with non-MG thymoma were included in this study. Furthermore, risk ratios (RR) with 95% confidence intervals (CI) were pooled using meta-analysis, and fixed-effects or random-effects models were used depending on the heterogeneity of the included studies.

Results

Thirteen cohorts containing 2,448 patients that met the inclusion criteria were included. Metaanalysis revealed that the incidence of PMG in preoperative patients with non-MG thymoma was 8%. Preoperative seropositive acetylcholine receptor antibody (AChR-Ab) (RR = 5.53, 95% CI 2.36 - 12.96, P<0.001), open thymectomy (RR =1.84, 95% CI 1.39 - 2.43, P<0.001), non-R0 resection (RR = 1.87, 95% CI 1.36 - 2.54, P<0.001), world health organization (WHO) type B (RR =1.80, 95% CI 1.07 - 3.04, P= 0.028), and postoperative inflammation (RR = 1.63, 95% CI 1.26 - 2.12, P<0.001) were the risk factors for PMG in patients with thymoma. Masaoka stage (P = 0.151) and sex (P = 0.777) were not significantly associated with PMG.

Discussion

Patients with thymoma but without MG had a high probability of developing PMG. Although the incidence of PMG was very low, thymectomy could not completely prevent the occurrence of MG. Preoperative seropositive AChR-Ab level, open thymectomy, non-R0 resection, WHO type B, and postoperative inflammation were risk factors for PMG.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022360002.

Predictive factors for postoperative myasthenic crisis in patients with myasthenia gravis

OBJECTIVES

Thymectomy plays an important role in the comprehensive treatment of myasthenia gravis. The present study aimed to investigate the risk factors for postoperative myasthenic crisis (POMC) in these patients and then establish a predicting model based on preoperatively available indicators.

METHODS

The clinical records of 177 consecutive patients with myasthenia gravis who received extended thymectomy between January 2018 and September 2022 in our department were retrospectively reviewed. Patients were divided into 2 groups according to whether they developed POMC. Univariate and multivariate regression analyses were conducted to identify the independent risk factors of POMC. Then a nomogram was constructed to intuitively show the results. Finally, the calibration curve and bootstrap resampling were used to evaluate its performance.

RESULTS

POMC occurred in 42 (23.7%) patients. By multivariate analysis, body mass index (P = 0.029), Osserman classification (P = 0.015), percentage of predicted forced vital capacity (pred%) (P = 0.044), percentage of predicted forced expiratory volume in the first second (pred%) (P = 0.043) and albumin to globulin ratio (P = 0.009) were identified as independent risk factors and entered into the nomogram. The calibration curve showed good concordance between the predicted and actual probability of prolonged ventilation.

CONCLUSIONS

Our model is a valuable tool for predicting POMC in myasthenia gravis patients. For those high-risk patients, appropriate preoperative treatment is necessary to improve the symptoms and greater attention to postoperative complications is needed.