Clinical characteristics and outcomes of thymoma-associated myasthenia gravis

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.

Defective autophagy and autophagy activators in myasthenia gravis: a rare entity and unusual scenario

Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction (NMJ) that results from autoantibodies against nicotinic acetylcholine receptors (nAchRs) at NMJs. These autoantibodies are mainly originated from autoreactive B cells that bind and destroy nAchRs at NMJs preventing nerve impulses from activating the end-plates of skeletal muscle. Indeed, immune dysregulation plays a crucial role in the pathogenesis of MG. Autoreactive B cells are increased in MG due to the defect in the central and peripheral tolerance mechanisms. As well, autoreactive T cells are augmented in MG due to the diversion of regulatory T (Treg) cells or a defect in thymic anergy leading to T cell-mediated autoimmunity. Furthermore, macroautophagy/autophagy, which is a conserved cellular catabolic process, plays a critical role in autoimmune diseases by regulating antigen presentation, survival of immune cells and cytokine-mediated inflammation. Abnormal autophagic flux is associated with different autoimmune disorders. Autophagy regulates the connection between innate and adaptive immune responses by controlling the production of cytokines and survival of Tregs. As autophagy is involved in autoimmune disorders, it may play a major role in the pathogenesis of MG. Therefore, this mini-review demonstrates the potential role of autophagy and autophagy activators in MG.Abbreviations: Ach, acetylcholine; Breg, regulatory B; IgG, immunoglobulin G; MG, myasthenia gravis; NMJ, neuromuscular junction; ROS, reactive oxygen species; Treg, regulatory T; Ubl, ubiquitin-like.

Improving Outcome in Severe Myasthenia Gravis and Guillain-Barré Syndrome

When progressive and severe, myasthenia gravis and Guillain-Barré syndrome may have the potential for fatal and unfavorable clinical outcomes. Regardless of important differences in their clinical course, the development of weakness of oropharyngeal muscles and respiratory failure with requirement of mechanical ventilation is the main driver of poor prognosis in both conditions. The need for prolonged mechanical ventilation is particularly relevant because it immobilizes the patient and care becomes extraordinarily complex due to daily risks of systemic complications. Additionally, patients with myasthenia gravis often require long-term immunosuppressive treatments with associated toxicity and infectious risks. Unlike myasthenia gravis, the recovery period is prolonged in Guillain-Barré syndrome, but often favorable, even in the more severely affected patients. Outcome, for a large part, is determined by expert neurocritical care.

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.

Diagnostic value of antibody concentration ratio for treatment-refractory myasthenia gravis

OBJECTIVE

This study aimed to assess the diagnostic potential of the Antibody concentration ratio in identifying treatment-refractory myasthenia gravis (MG).

METHODS

A retrospective analysis was conducted on 116 MG patients who underwent antibody detection at least twice between June 1, 2015, and June 1, 2023. Demographic and clinical characteristics were collated to ascertain their association with refractory MG. The Antibody Concentration Ratio was applied to determine treatment response, using the International Consensus Guidance criteria as the reference standard. The area under nonparametric receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy were calculated to assess the diagnostic efficacy of the Antibody concentration ratio following consecutive immunotherapy relative to initial antibody concentrations for refractory MG.

RESULTS

19 out of 116 patients were unequivocally diagnosed with refractory MG. A significant correlation was found between the Antibody Concentration Ratio and refractory MG status in treatment-refractory and treatment-responsive patients. Subsequently, the AUC demonstrated the robust diagnostic capability of the Antibody concentration ratio for refractory MG, with an AUC of 0.8709 (95% CI: 0.7995-0.9422, p < 0.0001). The optimal cut-off value stood at 0.8903, exhibiting a sensitivity of 94.74% (95% CI: 75.36%-99.73%), a specificity of 68.04% (95% CI: 58.23%-76.48%), and accuracy of 72.41% (95% CI: 64.28%-80.54%).

CONCLUSION

Elevated Antibody Concentration Ratio is intrinsically linked with refractory MG and exhibits potential as an diagnostic biomarker for the condition.

A new gene signature associated with disulfidptosis that forecasts myasthenia gravis and suggests infiltration of immune microenvironment in thymoma patients

Introduction

The mechanism of thymoma-associated myasthenia gravis (TAMG) is currently unknown, although patients with TAMG experience more severe myasthenic symptoms and have worse prognoses compared to regular thymoma patients. The objective of this research is to create a transcriptome map of TAMG using genes linked to disulfidptosis, detect possible biomarkers, and examine the disparities in the tumor immune microenvironment (TIME) among different thymoma patients. The findings will offer valuable knowledge for personalized treatment alternatives.

Methods

Thymoma samples' RNA-seq data, along with their corresponding clinical data, were acquired from the TCGA database using methods. Next, genes and disulfidptosis-related lncRNAs(DRLs) were chosen through correlation analysis. Then, a prediction model of TAMG was established by LASSO regression. Subsequent to that, an analysis of the mutation data, the tumor mutational burden (TMB), and the assessment of immune and stromal elements within the tumor microenvironment were conducted.

Results

A total of 87 patients diagnosed with thymoma were included in the study, with 29 of them having TAMG. We discovered a group of 325 lncRNAs in this sample that showed significant associations with genes related to disulfidptosis, with 25 of them displaying significantly altered expression. Moreover, utilizing LASSO regression, we constructed a predictive model incorporating 11 DRLs. The analysis revealed an area under the curve (AUC) of 0.934 (CI 0.879-0.989), a cut-off value of 0.797, along with a sensitivity of 82.8 % and specificity of 93.1 %. Furthermore, we examined the TIME in both the high-risk and low-risk groups, and observed noteworthy disparities in B cells, T cells, and APC among the two groups (p < 0.05).

Conclusion

This research offers the initial examination of genes associated with disulfidptosis and TAMG through genomic and transcriptomic analysis. Furthermore, a strong risk forecasting model was created and the significance of TIME in TAMG was also clarified. The discoveries offer significant understanding into the molecular processes of TAMG and present possible indicators for categorizing risk.

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.

Association between Cytotoxic T-Lymphocyte-Associated Antigen 4 (CTLA-4) Locus and Early-Onset Anti-acetylcholine Receptor-Positive Myasthenia Gravis in Serbian Patients

Genome-wide association studies (GWAS) have provided strong evidence that early- and late-onset MG have different genetic backgrounds. Recent in silico analysis based on GWAS results revealed rs231735 and rs231770 variants within CTLA-4 locus as possible MG causative genetic factors. We aimed to explore the association of rs231735 and rs231770 with MG in a representative cohort of Serbian patients. We conducted an age-, sex-, and ethnicity-matched case-control study. Using TaqMan allele discrimination assays, the frequency of rs231735 and rs231770 genetic variants was examined in 447 AChR-MG patients and 447 matched controls. There was no significant association of rs231735 and rs231770 with the entire MG cohort (P > 0.05). Nevertheless, when stratifying patients into early-onset (n = 183) and late-onset MG (n = 264), we found early-onset patients had a significantly lower frequency of the rs231735 allele T compared to controls (OR = 0.734, 95% CI = 0.575-0.938, p10e6 permutation < 0.05), and rs231735 genotype TT and rs231770 genotype TT had a protective effect on early-onset MG (OR = 0.548, 95% CI = 0.339-0.888, and OR = 0.563, 95% CI = 0.314-1.011, p10e6 permutation < 0.05). Consequently, we found that individuals with the rs231735-rs231770 haplotype GC had a higher risk for developing early-onset MG (OR = 1.360, P = 0.027, p10e6 permutation < 0.05). Our results suggest that CTLA-4 rs231735 and rs231770 may be risk factors only for patients with early-onset MG in Serbian population.

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.

Dexamethasone improves thymoma-associated myasthenia gravis via the AKT-mTOR pathway

Clinically, thymoma patients are often complicated with myasthenia gravis (MG). Dexamethasone, a glucocorticoid with anti-inflammatory effects, could be used as an immunosuppressant for thymoma-associated MG, but the mechanism of action remains to be explored. In this study, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, weighted gene co-expression network analysis (WGCNA) of potential targets was performed by screening the intersection targets of dexamethasone and thymoma-associated MG from the database. Furthermore, the key targets and core active components were identified by topological analysis of the protein-protein interaction (PPI) network. Molecular docking technology was applied to screen the complexes with stable binding of dexamethasone and core targets. Patients with thymoma were divided into two groups according to whether they received dexamethasone before operation, and immunohistochemistry and western blot were used to verify the selected target of dexamethasone in treating thymoma-associated MG. The results showed that the action pathway of dexamethasone on the disease was closely enriched to phosphatidylinositol 3-kinase (PI3K)-protein kinase B (PKB/AKT), mammalian target of rapamycin (mTOR) signaling pathways. The expressions of AKT1 and its downstream molecule mTOR in the thymoma microenvironment of thymoma-associated MG patients who did not receive dexamethasone before operation were higher than those in the group receiving dexamethasone before operation. This study demonstrates that dexamethasone can promote apoptosis through the AKT-mTOR pathway for the treatment of thymoma-associated MG, as validated by network pharmacology predictions and clinical specimen experiments, and can be verified by large-scale clinical trials in the future. This study also provides theoretical support and new research perspectives for this disease.

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.

Myasthenic crisis in thymoma-associated myasthenia gravis: a multicenter retrospective cohort study

Thymoma-associated myasthenia gravis (TMG) had more severe symptoms and worse prognoses in comparison to non-thymoma-associated MG. Thymoma recurrence was frequently associated with transient worsening of MG and even acute respiratory failure, namely myasthenic crisis (MC). However, little is known about the clinical features and outcomes of MC in thymoma-associated MG patients. We performed a retrospective cohort study in MG patients recruited from 9 independent tertiary neuromuscular centers in China from Jan 2015, through Oct 2022. Overall, 156 MC from 149 MG patients with positive anti-acetylcholine receptor (AChR) antibodies were finally analyzed. Next, these patients were divided into two subgroups: the TMG group (n = 60 MCs, 58 patients) and the non-thymoma-associated MG group (n = 96 MCs, 91 patients). Compared with non-thymoma-associated MG, TMG patients had a significantly shorter disease duration from symptom onset to the crisis (17.95±40.9 vs 51.31±60.61 months, P<0.0001), a larger proportion of MGFA IVa as the initial onset clinical classification (6.67% vs 0, P = 0.0205), and a longer hospital stay (39.24±22.09 [6-111] vs. 33.2 ± 23.42 days [7-120]; P = 0.0317) during the crisis. Within the TMG group, the hospital stay was significantly longer in patients with unresected thymoma compared to that in postoperative myasthenic crisis (POMC) (47.68±24.9 [6-111] vs. 34.21±18.87 days [12-82]; P = 0.0257). Early identification of the MG categories may provide some hints in tailoring therapeutic strategies to improve the prognosis.

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.

Prognosis of Concurrent Versus Sequential Chemo-Radiotherapy Induction Followed by Surgical Resection in Patients with Advanced Thymic Epithelial Tumors: A Retrospective Study

BACKGROUND

This study aimed to evaluate the prognosis of concurrent chemo-radiotherapy (CCRT) versus sequential chemo-radiotherapy (SCRT) induction followed by surgical resection in patients with advanced thymic epithelial tumors (TETs).

METHODS

This retrospective study included patients with advanced TETs who underwent CCRT or SCRT induction followed by surgical resection at the Second General Hospital of Guangdong Province between January 2008 and December 2019. The primary outcomes were induction response rate and surgical complete resection rate. The secondary outcomes were surgery combined resection, post-induction T staging, postoperative TNM staging, postoperative pathological tumor regression grade, progression-free survival (PFS) and overall survival (OS), and adverse events (AEs).

RESULTS

A total of 31 patients were included, 15 of whom received CCRT and the other 16 SCRT. The induction response rates were 80.0 and 62.5%, respectively, the post-induction step-down rates were 46.7 and 31.3%, respectively, and the post-induction R0 resection rates were 80.0 and 68.8%, respectively, without significant differences between CCRT and SCRT groups (all P > 0.05). The 5-year OS rate was 64.2 and 51.6%, respectively, and PFS was 42.3 and 21.4%, respectively, without significant differences between CCRT and SCRT groups (both P > 0.05). AEs in the hematologic system were significantly higher with CCRT compared with SCRT (P = 0.009).

CONCLUSIONS

Patients with advanced TETs might have a good prognosis with both CCRT and SCRT induction therapy, while SCRT induction may result in a lower probability of AEs in the hematologic system.

Occurrence and severity of myasthenic crisis in an unselected Turkish cohort of patients with myasthenia gravis

Myasthenia gravis (MG) is a disorder of the neuromuscular junction that can deteriorate into myasthenic crisis, involving weakness of bulbar and respiratory muscles. In this study, we describe the clinical manifestations of myasthenic crisis, identify risk factors, and examine treatments and outcomes. All 95 patients with generalized MG treated at our center during the last 10 years were included in this retrospective study. We collected data from the patients' records, including clinical follow-ups, muscle antibodies, thymic status, and treatments. The characteristics of patients who did and did not experience myasthenic crisis were compared. Features of all myasthenic crises were also assessed. Twelve patients (13%) developed myasthenic crisis during the observation period. Men were more often affected at older ages. Seven patients experienced multiple myasthenic crises. Thymoma increased the risk of a crisis, whereas thymic hyperplasia decreased the risk. Myasthenic crises were more common in the summer months. No patients died during a myasthenic crisis. Risk factors for myasthenic crisis were thymoma, older age, MuSK antibodies, and previous crises. Individualized and active immunosuppressive treatment and optimal intensive care during crises provide a good outcome for patients with generalized MG.

The Clinical Outcome in AChR-Positive Generalized Myasthenia Gravis: A Retrospective Observational Study

Background

Myasthenia gravis (MG) is an autoimmune disease affecting the neuromuscular junction, and in over 80% of cases, antibodies are identified against the nicotinic type of acetylcholine receptor (AChR) on the muscle endplate. Despite the availability of various treatment options, patients with MG experience relapses and remission during the course of the disease. Aims and Objective: To understand the clinical profile, predictors of outcomes in acetyl choline receptor (AChR) antibody positive generalized MG.

Methods

This is a retrospective, single-centre, observational study of 108 patients with AChR positive generalized MG. We collected data on clinical and demographical profiles, treatments received, and treatment responses from those who fulfilled inclusion criteria over a mean follow up period of 33.75 ±7.30 months. Clinical outcomes were studied in terms of the type of remission and crisis or disease exacerbations patients had, considering different variables and treatment received.

Results

We found the commonest initial symptoms were ocular or oculo-bulbar, which progressed to generalized MG in the first year of disease onset. 36 (33.3%) patients experienced a crisis requiring mechanical ventilation within a mean period of 9.4 ±4.77 months from the disease onset. Multivariate regression analysis showed late-onset MG (age of onset between 50-70 years) and treatment with rituximab were better correlated with remission, (odd ratio of 4.7; 95 % CI ,1.12 -12.6; P value < 0.05 and odd ratio of 4.56; 95 % CI ,1.2 -10.04; P value < 0.05) respectively. While treatment with Mycofenolate Mofetile (MMF) was associated with a higher number of relapses (odd ratio of 1.8; 95 % CI ,0.08 -0.96; P value < 0.05). Treatment with Rituximab showed a higher rate of remission as compared to treatment refractory (TR) on conventional immunosuppressant therapy (IST). Out of 35(32 %) thymoma patients, 21 patients underwent thymectomy and these patients showed significantly greater rate of remission as compared both thymoma patients who denied thymectomy as a treatment option (N = 10 ;55.60 % vs N = 4; 23.50%).

Conclusion

In this study of AChR antibody positive generalized MG patients, we found that nearly one-third of them experienced myasthenic crisis despite receiving the best medical care. Rituximab appeared to be effective in the treatment of refractory MG and those who failed thymectomy. Thymectomy was associated with better outcomes in patients, both with or without a thymoma.

An unusual ectopic thymoma clonal evolution analysis: A case report

Thymomas and thymic carcinomas are rare and primary tumors of the mediastinum which is derived from the thymic epithelium. Thymomas are the most common primary anterior mediastinal tumor, while ectopic thymomas are rarer. Mutational profiles of ectopic thymomas may help expand our understanding of the occurrence and treatment options of these tumors. In this report, we sought to elucidate the mutational profiles of two ectopic thymoma nodules to gain deeper understanding of the molecular genetic information of this rare tumor and to provide guidance treatment options. We presented a case of 62-year-old male patient with a postoperative pathological diagnosis of type A mediastinal thymoma and ectopic pulmonary thymoma. After mediastinal lesion resection and thoracoscopic lung wedge resection, the mediastinal thymoma was completely removed, and the patient recovered from the surgery and no recurrence was found by examination until now. Whole exome sequencing was performed on both mediastinal thymoma and ectopic pulmonary thymoma tissue samples of the patient and clonal evolution analysis were further conducted to analyze the genetic characteristics. We identified eight gene mutations that were co-mutated in both lesions. Consistent with a previous exome sequencing analysis of thymic epithelial tumor, HRAS was also observed in both mediastinal lesion and lung lesion tissues. We also evaluated the intratumor heterogeneity of non-silent mutations. The results showed that the mediastinal lesion tissue has higher degree of heterogeneity and the lung lesion tissue has relatively low amount of variant heterogeneity in the detected variants. Through pathology and genomics sequencing detection, we initially revealed the genetic differences between mediastinal thymoma and ectopic thymoma, and clonal evolution analysis showed that these two lesions originated from multi-ancestral regions.

Clinical and immune-related factors associated with exacerbation in adults with well-controlled generalized myasthenia gravis

Objectives

To describe the clinical predictors and immune-related factors for exacerbation in adults with well-controlled generalized myasthenia gravis (GMG).

Methods

We conducted a retrospective analysis of 585 adults with well-controlled GMG from our institution to explore the risk factors for exacerbation. Furthermore, propensity score matching (PSM) was used to compare the proportions of lymphocyte subsets, and the levels of immunoglobulin, complement, and anti-acetylcholine receptor antibody (AChR-ab) in the peripheral blood of 111 patients with exacerbations and 72 patients without exacerbations.

Results

A total of 404 patients (69.1%) experienced at least one exacerbation, and the median (interquartile range) time to the first exacerbation was 1.5 years (0.8-3.1 years). Multivariable Cox regression analysis showed that age at onset, disease duration before enrollment, Myasthenia Gravis Foundation of America classification (MGFA) class III vs. class II, MGFA class IV-V vs. class II, AChR-ab levels, anti-muscle specific kinase antibody levels, thymus hyperplasia, prednisone plus immunosuppressants vs. prednisone treatment, and thymectomy were independent predictors for exacerbations [hazard ratio (HR) = 1.011, 1.031, 1.580, 1.429, 2.007, 2.033, 1.461, 0.798, and 0.651, respectively]. Propensity-matched analysis compared 51 patient pairs. After PSM, the peripheral blood proportions of CD3^-CD19⁺ B cells, ratios of CD3⁺CD4⁺/CD3⁺CD8⁺ T cells, and AChR-ab levels were significantly increased, and the peripheral blood proportions of CD3⁺CD8⁺ T and CD4⁺CD25⁺CD127^low+ regulatory T cells (Tregs) were significantly lower in patients with exacerbation than in those without exacerbation (all p < 0.05).

Conclusion

Myasthenia gravis (MG) exacerbations were more frequent in those patients with older onset age, longer disease duration, more severe MGFA classification, positive AChR-ab, and lack of combined immunotherapy or thymectomy treatment. On the other hand, CD3^-CD19⁺ B cells, CD3⁺CD8⁺ T cells, Tregs, and AChR-ab in peripheral blood may be involved in the course of GMG exacerbation.

Safety of COVID-19 vaccine in patients with myasthenia gravis: a self-controlled case series study

Background

The safety of COVID-19 vaccines has been clarified in clinical trials; however, some immunocompromised patients, such as myasthenia gravis (MG) patients, are still hesitant to receive vaccines. Whether COVID-19 vaccination increases the risk of disease worsening in these patients remains unknown. This study aims to evaluate the risk of disease exacerbation in COVID-19-vaccinated MG patients.

Methods

The data in this study were collected from the MG database at Tangdu Hospital, the Fourth Military Medical University, and the Tertiary Referral Diagnostic Center at Huashan Hospital, Fudan University, from 1 April 2022 to 31 October 2022. A self-controlled case series method was applied, and the incidence rate ratios were calculated in the prespecified risk period using conditional Poisson regression.

Results

Inactivated COVID-19 vaccines did not increase the risk of disease exacerbation in MG patients with stable disease status. A few patients experienced transient disease worsening, but the symptoms were mild. It is noted that more attention should be paid to thymoma-related MG, especially within 1 week after COVID-19 vaccination.

Conclusion

COVID-19 vaccination has no long-term impact on MG relapse.

The Duke Myasthenia Gravis Clinic Registry: II. Analysis of outcomes

INTRODUCTION/AIMS

The Duke Myasthenia Gravis (MG) Clinic Registry contains comprehensive physician-derived data on patients with MG seen in the Duke MG Clinic since 1980. The aim of this study was to report outcomes in patients seen in the clinic and treated according to the International Consensus Guidance statements.

METHODS

This is a retrospective cohort study of patients initially seen after 2000 and followed for at least 2 years in the clinic. Treatment goal (TG) was defined as achieving MGFA post-intervention status of "minimal manifestations" or better; PIS was determined by the treating neurologist. Time-to-event analysis, including Cox proportional hazards modeling, was performed to assess the effect of sex, acetylcholine receptor antibody (AChR-Ab) status, age at disease onset, distribution (ocular vs generalized), thymectomy, and thymoma on the time to achieve TG.

RESULTS

Among the 367 cohort patients, 72% achieved TG (median time less than 2 years). A greater proportion of patients with AChR-Abs and thymectomy achieved TG and they did so sooner than patients without these antibodies or thymectomy. Otherwise, there were no significant differences in these findings within the tested subgroups. The disease duration at the first Duke Clinic visit was shorter in patients who achieved TG than in those who did not.

DISCUSSION

These results demonstrate outcomes that can be achieved in patients with MG treated according to the current Consensus Guidance statements. Among other things, they can be used to determine the added value and potential role of new treatment modalities developed since 2018.

Thymoma-associated autoimmune encephalitis: Analysis of factors determining prognosis

INTRODUCTION

Autoimmune encephalitis (AE) is a heterogeneous group of inflammatory central nervous system disorders caused by a misdirected immune response against self-antigens expressed in the central nervous system. The thymus is a central organ in the immune system and thymic tumors are thought to be possible initiators of many neurological disorders. Recently, there is growing evidence that thymomas are associated with autoimmune encephalitis.

AIMS

Our study initially explored the characteristics of patients with autoimmune encephalitis combined with thymoma.

METHODS

We used patient data from January 1, 2011 to October 1, 2021 from the PubMed, Web of Science, Ovid, and CNKI platforms to analyze overall demographics, frequency of symptoms and associations, and treatment prognosis outcomes.

RESULTS

A total of 68 patients were included. There were 39 female cases (57.4%). The mean age was 50 years (IQR 40-66 years). All had acute and subacute onset. The clinical manifestations were mostly cognitive changes (70.6%), mental disorders (57.4%), and epilepsy (50.0%). The most common neuronal antibody was alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Magnetic resonance imaging (MRI) abnormalities were present in 81.0% of patients, mostly in the hippocampus, temporal lobe, and some in cortical and subcortical areas. Abnormalities in the electroencephalogram (EEG) in 69.8% of patients. Treatment involved immunotherapy and thymoma treatment, with 79.7% of patients improving after treatment. While 20.3% of patients had a poor prognosis. Further, 14.8% of patients relapsed. Mental disorders, autonomic dysfunction, sleep disturbances, anti-Ma2, and thymoma untreated were more frequent in patients with poor prognosis.

CONCLUSION

Thymoma-associated autoimmune encephalitis is a unique disease entity. Long-term follow-up of chest CT findings is recommended for patients with autoimmune encephalitis.

Anti-dsDNA Is Associated with Favorable Prognosis in Myasthenia Gravis: A Retrospective Study

Objectives. To investigate the presence of serum antinuclear antibody (ANA) and anti-double-stranded DNA antibody (anti-dsDNA) in patients with myasthenia gravis (MG) and analyze the clinical characteristics and prognostic factors associated with MG. Methods. We retrospectively enrolled 363 patients with MG and analyzed the clinical characteristics and follow-up data between patients positive and negative for ANA and anti-dsDNA. We defined a Myasthenia Gravis Activities of Daily Living (MG-ADL) reduction as a main prognosis predictor and used logistic regression to determine independent factors associated with prognosis. We built a nomogram to predict prognosis and evaluate the internal validity of the model. Results. Ninety-eight (27.0%) patients were positive for ANA, and 51 (14.0%) were positive for anti-dsDNA. Patients positive for ANA and anti-dsDNA antibodies tended to be female and positive for acetylcholine receptor antibody (AChR-Ab). The rate of thymoma was higher in anti-dsDNA-positive patients with MG (p-dsDNA-MG) than in patients negative for anti-dsDNA (49.0% vs. 26.0%, $p=0.001$ ), and p-dsDNA-MG was associated with reduced MG-ADL score. Regression analysis showed that except for age of onset ( $\text{OR}=0.986$ , $95\%\text{CI}=0.973–0.999$ , $p=0.037$ ), anti-dsDNA ( $\text{OR}=2.800$ , $95\%\text{CI}=1.381–5.679$ , $p=0.004$ ), ptosis ( $\text{OR}=2.930$ , $95\%\text{CI}=1.827–4.699$ , $p<0.001$ ), and eye movement disorder ( $\text{OR}=2.815$ , $95\%\text{CI}=1.672–4.741$ , $p<0.001$ ) were independent predictive factors of a favorable prognosis of MG. These predictors were used to generate a nomogram with an excellent predictive value. Conclusions. Being female and the presence of AChR-Ab were features of ANA- or anti-dsDNA-positive MG. The presence of anti-dsDNA was associated with a favorable prognosis of MG.

Postoperative clinical outcomes of patients with thymic epithelial tumors after over-3-year follow-up at a single-center

BACKGROUND

To evaluate postoperative clinical outcomes and analyze influencing factors for patients with thymic epithelial tumors over 3 years after operation.

METHODS

Patients with thymic epithelial tumors (TETs) who underwent surgical treatment in the Department of Thoracic Surgery at Beijing Hospital from January 2011 to May 2019 were retrospectively enrolled in the study. Basic patient information, clinical, pathological, and perioperative data were collected. Patients were followed up by telephone interviews and outpatient records. Statistical analyses were performed using SPSS version 26.0.

RESULTS

A total of 242 patients (129 men, 113 women) with TETs were included in this study, of which 150 patients (62.0%) were combined with myasthenia gravis (MG) and 92 patients (38.0%) were not. 216 patients were successfully followed up and their complete information was available. The median follow-up period was 70.5 months (range, 2-137 months). The 3-year overall survival (OS) rate of the whole group was 93.9%, and the 5-year OS rate was 91.1%. The 3-year relapse-free survival (RFS) rate of the whole group was 92.2%, and the 5-year relapse-free survival rate was 89.8%. Multivariable COX regression analysis indicated that recurrence of thymoma was an independent risk factor for OS. Younger age, Masaoka-Koga stage III + IV, and TNM stage III + IV were independent risk factors for RFS. Multivariable COX regression analysis indicated that Masaoka-Koga staging III + IV, WHO type B + C were independent risk factors for postoperative improvement of MG. For patients with MG, the postoperative complete stable remission (CSR) rate was 30.5%. And the result of multivariable COX regression analysis showed that thymoma patients with MG with Osserman staging IIA + IIB + III + IV were not prone to achieving CSR. Compared with patients without MG, MG was more likely to develop in patients with WHO classification type B, and patients with myasthenia gravis were younger, with longer operative duration, and more likely to develop perioperative complications.

CONCLUSIONS

The 5-year overall survival rate of patients with TETs was 91.1% in this study. Younger age and advanced stage were independent risk factors for RFS of patients with TETs, and recurrence of thymoma were independent risk factors for OS. In patients with MG, WHO classification type B and advanced stage were independent predictors of poor outcomes of MG treatment after thymectomy.

Identification of Potential Serum Protein Biomarkers in Thymoma with Myasthenia Gravis After Docetaxel Treatment

INTRODUCTION

Myasthenia gravis (MG) is a devastating acquired autoimmune disease that can seriously affect the patient's quality of life. It is also a common complication of thymoma. Previous studies have shown that docetaxel alleviates myasthenic symptoms in thymoma with MG (TMG). However, little is known about the protein expression profiles and biomarkers for efficacy after docetaxel treatment.

METHODS

We recruited 9 healthy controls and 30 patients with TMG for the serum proteomics study with data-independent acquisition (DIA) technology. We further recruited additional 30 patients for the key protein validation by enzyme-linked immunosorbent assay (ELISA).

RESULTS

We identified 43 proteins by trend analysis and analyzed the interaction between these proteins and MG pathogenic proteins from the DisGNET database and the correlation analysis with clinical data of patients with TMG. Among these, KRAS and SELP were screened out and validated. KRAS and SELP increased in patients with TMG and decreased significantly after docetaxel treatment.

CONCLUSIONS

Our study revealed that the serum proteins were differentially expressed after docetaxel treatment, suggesting their important role in patients with TMG, as well as the critical role of KRAS and SELP as biomarkers in evaluating the efficacy of docetaxel treatment.

Myocardial Injury in Hospitalized Patients with Myasthenia Gravis

Objective: To investigate the clinical characteristics and outcome of myocardial injury in patients with myasthenia gravis (MG). Methods: We retrospectively searched medical records to screen hospitalized patients with MG at our hospital. The troponin T (TnT) levels were deemed necessary to be performed based on the patient’s clinical symptoms and were used as biomarkers of myocardial injury. The patients’ demographic and clinical information were collected. Death was the primary outcome. Results: A total of 336 patients with MG measured TnT levels and were included in the final analysis. The male MG patients with elevated TnT levels had a higher prevalence of infection (56.8% vs. 30.0%, p = 0.001) and myasthenic crisis (37.5% vs. 13.3%, p = 0.001) than those with normal TnT levels. Meanwhile, the female MG patients with elevated TnT levels were older (56.0 (16.6) vs. 49.2 (17.2)) years old, p = 0.007] and had a higher prevalence of infection (65.4% vs. 32.1%, p < 0.001), myasthenic crisis (33.6% vs. 17.9%, p = 0.015), and thymoma (38.5% vs. 16.7%, p = 0.001) than those with normal TnT levels. Older age (coef. = 0.004; p = 0.034), infection (coef. = 0.240; p = 0.001), myasthenic crisis (coef. = 0.312; p < 0.001), thymoma (coef. = 0.228; p = 0.001), and ICI therapy (coef. = 1.220; p < 0.001) were independent risk predictors for increasing log TnT levels. Thirty-seven patients died during hospitalization. High log TnT levels (OR = 8.818; p < 0.001), female sex (OR = 0.346; p = 0.023), thymoma (OR = 5.092; p = 0.002), and infection (OR = 14.597; p < 0.001) were independent risk predictors of death. Conclusions: Our study revealed that the surveillance of myocardial injury biomarkers in MG patients might be beneficial.

Case report: Complex paraneoplastic syndromes in thymoma with nephrotic syndrome, cutaneous amyloidosis, myasthenia gravis, and Morvan’s syndrome

Background

Apart from myasthenia gravis (MG), thymoma is associated with a wide spectrum of autoimmune paraneoplastic syndromes (PNSs). Here, we report on a rare case presenting with four different PNSs, namely, MG, membranous nephropathy, cutaneous amyloidosis, and Morvan’s syndrome associated with thymoma.

Case presentation

A middle-aged man was frequently hospitalized because of nephrotic syndrome (stage I membranous nephropathy), cutaneous amyloidosis, and MG with acetylcholine receptor (AChR) antibody and titin antibody positivity. Chest CT showed a thymic mass in the left anterior mediastinum, and he received intravenous immunoglobulin (IVIG), methylprednisolone pulse therapy, thoracoscopic thymoma resection, and radiotherapy. Postoperative pathological examination revealed a type B2 thymoma. During the perioperative stage, his electrocardiogram (ECG) showed myocardial infarction-like ECG changes; however, his levels of cardiac enzymes and troponin were normal, and he had no symptoms of precardiac discomfort. Six months after thymectomy, his nephrotic syndrome and MG symptoms were relieved; however, he presented with typical manifestations of Morvan’s syndrome, including neuromyotonia, severe insomnia, abnormal ECG activity, and antibodies against leucine-rich glioma-inactivated 1 (LGI1) and γ-amino-butyric acid-B receptor (GABABR). His symptoms did not improve after repeated IVIG and steroid therapies. Finally, he received low-dose rituximab, and his symptoms gradually resolved.

Conclusion

This case serves to remind us that apart from MG, thymoma is also associated with other autoimmune PNSs such as membranous nephropathy, cutaneous amyloidosis, and Morvan’s syndrome. Autoimmune PNSs can present concurrently with or after surgical or medical therapy for thymoma. For Morvan’s syndrome post-thymectomy with LGI1 antibody positivity, B-cell depletion therapy such as intravenous rituximab is an effective treatment.

Novel pathophysiological insights in autoimmune myasthenia gravis

PURPOSE OF REVIEW

This review summarizes recent insights into the immunopathogenesis of autoimmune myasthenia gravis (MG). Mechanistic understanding is presented according to MG disease subtypes and by leveraging the knowledge gained through the use of immunomodulating biological therapeutics.

RECENT FINDINGS

The past two years of research on MG have led to a more accurate definition of the mechanisms through which muscle-specific tyrosine kinase (MuSK) autoantibodies induce pathology. Novel insights have also emerged from the collection of stronger evidence on the pathogenic capacity of low-density lipoprotein receptor-related protein 4 autoantibodies. Clinical observations have revealed a new MG phenotype triggered by cancer immunotherapy, but the underlying immunobiology remains undetermined. From a therapeutic perspective, MG patients can now benefit from a wider spectrum of treatment options. Such therapies have uncovered profound differences in clinical responses between and within the acetylcholine receptor and MuSK MG subtypes. Diverse mechanisms of immunopathology between the two subtypes, as well as qualitative nuances in the autoantibody repertoire of each patient, likely underpin the variability in therapeutic outcomes. Although predictive biomarkers of clinical response are lacking, these observations have ignited the development of assays that might assist clinicians in the choice of specific therapeutic strategies.

SUMMARY

Recent advances in the understanding of autoantibody functionalities are bringing neuroimmunologists closer to a more detailed appreciation of the mechanisms that govern MG pathology. Future investigations on the immunological heterogeneity among MG patients will be key to developing effective, individually tailored therapies.

Poor responses and adverse outcomes of myasthenia gravis after thymectomy: Predicting factors and immunological implications

Myasthenia gravis (MG) has been recognized as a series of heterogeneous but treatable autoimmune conditions. As one of the indispensable therapies, thymectomy can achieve favorable prognosis especially in early-onset generalized MG patients with seropositive acetylcholine receptor antibody. However, poor outcomes, including worsening or relapse of MG, postoperative myasthenic crisis and even post-thymectomy MG, are also observed in certain scenarios. The responses to thymectomy may be associated with the general characteristics of patients, disease conditions of MG, autoantibody profiles, native or ectopic thymic pathologies, surgical-related factors, pharmacotherapy and other adjuvant modalities, and the presence of comorbidities and complications. However, in addition to these variations among individuals, pathological remnants and the abnormal immunological milieu and responses potentially represent major mechanisms that underlie the detrimental neurological outcomes after thymectomy. We underscore these plausible risk factors and discuss the immunological implications therein, which may be conducive to better managing the indications for thymectomy, to avoiding modifiable risk factors of poor responses and adverse outcomes, and to developing post-thymectomy preventive and therapeutic strategies for MG.

Immunodeficiency in patients with thymoma-associated myasthenia gravis

Thymoma with immunodeficiency is sometimes accompanied by myasthenia gravis (MG), but the clinical characteristics have not been elucidated. This study aimed to characterize its clinical and immunological features. Of the 132 thymoma-associated MG patients, 9 patients presented with immunodeficiency. All suffered from severe pneumonia, and most had invasive thymoma and autoimmune disorders. DRB1*08:03 and DQB1*06:01 alleles were frequently detected. Compared to group without immunodeficiency, they showed no significant differences in the severity of MG, significantly lower IgG concentrations and higher mortality rate. Thymoma-associated MG with immunodeficiency is a distinct subset requiring special attention to prevent infection during the follow-up period.

Does Myasthenia Gravis Affect Long-Term Survival in Thymic Carcinomas? An ESTS Database Analysis

Background: Thymic carcinoma is a rare and highly malignant tumor with a dismal prognosis, which occasionally coexists with myasthenia gravis (MG). This study aims to investigate the MG incidence on a surgical cohort of patients with thymic carcinoma and to explore its influence on long-term survival. Methods: the prospectively collected data from the ESTS database on thymic epithelial tumors were reviewed. Clinical, pathological, and survival information on thymic carcinoma were analyzed. Results: the analysis was conducted on 203 patients, with an equal gender distribution (96 males and 107 females). MG was detected in 22 (10.8%) patients, more frequently elderly (>60 years, p = 0.048) and male (p = 0.003). Induction therapy was performed in 22 (10.8%) cases. After surgery, 120 (59.1%) patients had a Masaoka stage II−III while complete resection (R0) was achieved in 158 (77.8%). Adjuvant therapy was performed in 68 cases. Mean follow-up was 60 (SD = 14) months. The 3-year, 5-year and 10-year survival rates were 79%, 75% and 63%, respectively. MG did not seem to influence long-term survival (5-year survival in non-MG−TCs 78% vs. 50% in MG−TCs, p = ns) as age < 60 years, female gender, early Masaoka stage, and postoperative radiotherapy did, conversely. Conclusions: myasthenia occurred in about 10% of thymic carcinomas and it did not seem to affect significantly the long-term prognosis in surgically treated thymic carcinoma-patients.

Paraneoplastic syndrome in neuroophthalmology

Paraneoplastic syndrome is a group of clinical symptoms that occur in the state of systemic malignant tumors. Paraneoplastic syndrome of the nervous system can affect any part of the central and peripheral nervous system and may also affect the eyes. In neuroophthalmology, paraneoplastic syndrome has a variety of manifestations that can affect both the afferent and efferent visual systems. The afferent system may involve the optic nerve, retina and uvea; the efferent system may involve eye movement, neuromuscular joints or involuntary eye movements and pupil abnormalities and may also have other neurological symptoms outside the visual system. This article discusses the clinical manifestations, pathological mechanisms, detection methods and treatment methods of paraneoplastic syndrome in neuroophthalmology. The performance of paraneoplastic syndrome is diverse, the diagnosis is difficult, and the treatment should be considered systematically. Differential diagnosis, optimal evaluation and management of these manifestations is not only the key to treatment but also a challenge.

Paraneoplastic autoimmune hypophysitis: An emerging concept

Pituitary autoimmunity is one of the principal causes of hypopituitarism. Additionally, hypophysitis is one of the immune-related adverse events associated with immunotherapy. Recent case-oriented research has revealed a novel type of autoimmune hypophysitis, anti-PIT-1 hypophysitis, related to isolated adrenocorticotropic hormone (ACTH) deficiency and immune checkpoint inhibitor-related hypophysitis, as a form of paraneoplastic syndrome. Under these conditions, the ectopic expression of pituitary antigens present in tumors evokes a breakdown of immune tolerance, resulting in the production of autoantibodies and autoreactive cytotoxic T cells that specifically harm pituitary cells. Consequently, an innovative clinical entity of paraneoplastic autoimmune hypophysitis has been purported. This novel concept and its underlying mechanisms provide clues for understanding the pathogenesis of autoimmune pituitary diseases and can be applied to other autoimmune diseases. This review discusses the etiology of paraneoplastic autoimmune hypophysitis and its future.

Outcomes of extended surgical resections for locally advanced thymic malignancies: a narrative review

BACKGROUND AND OBJECTIVE

Thymic malignancies represent the most common anterior mediastinal neoplasms, as well as rare and challenging tumors. Surgery is the cornerstone in the treatment of thymic malignancies, although a multidisciplinary approach is mandatory, for both, locally advanced or metastatic disease. In our narrative review, we explored the recent literature to investigate clinical and radiological assessment, multimodality approach and outcomes of locally advanced thymic tumors. More than one-third of patients affected by an anterior mediastinal mass are asymptomatic at diagnosis. In case of locally advanced thymoma, symptoms are related to compression or invasion of adjacent structures, such as the superior vena cava (SVC), innominate veins and pericardium. Paraneoplastic syndromes, such as myasthenia gravis (MG), are related to release of antibodies, hormones and cytokines.

METHODS

Diagnostic methods must be chosen accurately to avoid unnecessary surgical resections, to define the best strategy of care, and to plan the surgical strategy. Therefore, each case must be evaluated in a multidisciplinary context, where surgery plays an essential role.

KEY CONTENT AND FINDINGS

In this narrative review, we describe indications and surgical techniques for the treatment of locally advanced thymoma; focusing on oncological outcomes after different approaches.

CONCLUSIONS

In conclusion, aggressive surgery is always indicated, when possible, and when a complete resection can be planned, yet, the multidisciplinary approach is mandatory, in case of both locally or metastatic advanced disease.

Drug-refractory myasthenia gravis: Clinical characteristics, treatments, and outcome

Objective

To describe the clinical characteristics and outcomes in patients with refractory myasthenia gravis (MG) and to determine the effectiveness and side effects of the drugs used for their treatment.

Methods

This observational retrospective cross‐sectional multicenter study was based on data from the Spanish MG Registry (NMD‐ES). Patients were considered refractory when their MG Foundation of America post‐interventional status (MGFA‐PIS) was unchanged or worse after corticosteroids and two or more other immunosuppressive agents. Clinical and immunologic characteristics of drug‐refractory patients, efficiency and toxicity of drugs used, and outcome (MGFA‐PIS) at end of follow‐up were studied.

Results

We included 990 patients from 15 hospitals. Eighty‐four patients (68 of 842 anti‐acetylcholine receptor [AChR], 5 of 26 anti‐muscle‐specific tyrosine kinase [MusK], 10 of 120 seronegative, and 1 of 2 double‐seropositive patients) were drug refractory. Drug‐refractory patients were more frequently women (p < 0.0001), younger at onset (p < 0.0001), and anti‐MuSK positive (p = 0.037). Moreover, they more frequently presented a generalized form of the disease, bulbar symptoms, and life‐threatening events (p < 0.0001; p = 0.018; and p = 0.002, respectively) than non‐drug‐refractory patients. Mean follow‐up was 9.8 years (SD 4.5). Twenty‐four (50%) refractory patients had side effects to one or more of the drugs. At the end of follow‐up, 42.9% of drug‐refractory patients (42.6% of anti‐AChR, 100% of anti‐MuSK, and 10% of seronegative patients) and 79.8% of non‐drug‐refractory patients (p < 0.0001) achieved remission or had minimal manifestations. Eighty percent of drug‐refractory‐seronegative patients did not respond to any drug tested.

Interpretation

In this study, 8.5% of MG patients were drug‐refractory. New more specific drugs are needed to treat drug‐refractory MG patients.