Generalized Myasthenia Gravis: Classification, Clinical Presentation, Natural History, and Epidemiology

The safety and efficacy profile of eculizumab in myasthenic crisis: a prospective small case series

Eculizumab has improved recovery from ventilatory support in myasthenic crisis (MC) cases. However, the safety and efficacy profiles from prospective studies are still lacking. This study aimed to explore eculizumab's safety and efficacy in a prospective case series of patients with refractory MC. We followed a series of anti-acetylcholine receptor (AChR) antibody-positive myasthenia gravis (MG) patients who received eculizumab as an add-on therapy for 12 weeks during MC to facilitate the weaning process and reduced disease activity. Serum anti-AChR antibodies and peripheral immune molecules associated with the complement pathway were evaluated before and after eculizumab administration. Compared to the baseline Myasthenia Gravis Foundation of America (MGFA)-quantitative MG test (QMG) scores (22.25 ± 4.92) and MG-activities of daily living (MG-ADL; 18.25 ± 2.5) scores at crisis, improvements were observed from 4 weeks (14.5 ± 10.47 and 7.5 ± 7.59, respectively) through 12 weeks (7.5 ± 5.74 and 2.25 ± 3.86, respectively) post-treatment. Muscle strength consistently improved across ocular, bulbar, respiratory, and limb/gross domain groups. One patient died of cardiac failure at 16 weeks. Three cases remained in remission at 24 weeks, with a mean QMG score of 2.67 ± 2.89 and ADL score of 0.33 ± 0.58. No significant side effects were reported. Serum CH50 and soluble C5b-9 levels significantly declined, while there were no significant changes in serum anti-AChR antibody levels, C1q, C5a levels, or peripheral lymphocyte proportions. Eculizumab was well tolerated and showed efficacy in this case series. Large prospective cohort studies with extended follow-up periods are needed to further explore the safety and efficacy profile in real-world practice.

Economic burden of generalized myasthenia gravis (MG) in the United States and the impact of common comorbidities and acute MG-events

BACKGROUND

This study assessed the incremental healthcare costs and resource utilization (HRU) associated with generalized myasthenia gravis (gMG), as well as variability in these outcomes among patients with gMG and common comorbidities and acute MG-related events.

METHODS

Adults with gMG and without MG were identified from a large US database (2017-2021). The index date was the first MG diagnosis (gMG cohort) or random date (non-MG cohort). Cohorts were propensity score matched 1:1. The gMG cohort included subgroups of patients with a 12-month pre-index (baseline) cardiometabolic or psychiatric comorbidity, or a post-index MG exacerbation/crisis. Monthly healthcare costs (2021 USD) and HRU were compared post-index between gMG and non-MG cohorts.

RESULTS

The gMG and matched non-MG cohorts each contained 2,739 patients. Mean incremental healthcare costs associated with MG were $4,155 (gMG: $5,567; non-MG: $1,411), with differences driven by incremental inpatient costs of $2,166 (gMG: $2,617; non-MG: $452); all p < 0.001. The gMG versus non-MG cohort had 4.36 times more inpatient admissions and 2.26 times more outpatient visits; all p < 0.001. Among patients with gMG in cardiometabolic (n = 1,859), psychiatric (n = 1,308), and exacerbation/crisis (n = 419) subgroups, mean monthly healthcare costs were $6,660, $7,443, and $17,330, respectively.

CONCLUSIONS

gMG is associated with substantial incremental costs and HRU, with inpatient costs driving the total incremental costs. Costs increased by 20% and 34% among patients with cardiometabolic and psychiatric conditions, respectively, and over three times among those with acute MG-related events. gMG is a complex disease requiring management of comorbidities and treatment options that can prevent acute symptomatic events.

Heterogeneous Presentations and Serologies in Myasthenia Gravis Patients Presenting with Dysphagia

INTRODUCTION

Myasthenia gravis (MG) is an autoimmune disease that affects the neuromuscular junction. MG patients may present de novo with primary otolaryngology complaints, including swallowing dysfunction. This study describes a range of unique presentations and rare diagnostic serologies, which have not previously been fully described.

METHODS

A retrospective review was performed of all patients presenting with primary symptom of dysphagia and subsequently diagnosed with MG. Data collected included demographics, clinical presentation, swallow studies, serology, imaging, treatment, and response.

RESULTS

Five patients met the inclusion criteria. Four endorsed dysphagia as primary complaint and one endorsed dysphagia and dysphonia. All patients underwent in-office swallow evaluations that showed vallecular or pyriform sinus residue. Three patients completed modified barium swallow studies that showed pharyngeal weakness and epiglottic dysfunction in all, and upper esophageal sphincter dysfunction in two. One patient with additional symptom of dyspnea was admitted and found to be in myasthenic crisis. Upon serologic evaluation, three patients were positive for acetylcholine receptor (AChR) antibodies only, one for muscle-specific-kinase (MuSK) antibodies only, and one for low density lipoprotein receptor-related protein 4 (LRP4) antibodies only. All patients received neurology evaluation and were treated with steroids, pyridostigmine, plasma exchange, or rituximab. In three patients with over 1 year follow-up, symptoms were significantly improved or resolved.

CONCLUSION

MG is an important differential diagnosis in patients with unexplained pharyngeal dysphagia. While workup can include AChR antibody screening, in seronegative patients with persistent symptoms, additional testing for MuSK and LRP4 may lead to diagnosis and effective treatment.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 2024.

Clinical Characteristics and Outcomes of Generalized Myasthenia Gravis in Malaysia: A Single-Center Experience

BACKGROUND AND PURPOSE

Myasthenia gravis (MG) is clinically heterogeneous and can be classified into subgroups according to the clinical presentation, antibody status, age at onset, and thymic abnormalities. This study aimed to determine the clinical characteristics and outcomes of generalized MG (GMG) patients based on these subgroups.

METHODS

Medical records of MG patients from 1976 to 2023 were reviewed retrospectively. Patients with pure ocular MG were excluded. Data on demographic, clinical characteristics, laboratory features, and outcomes were analyzed.

RESULTS

This study included 120 GMG patients. There was a slight preponderance of female patients over male patients (male:female ratio=1:1.3), with the age at onset exhibiting a bimodal distribution. Female patients peaked at a lower age (21-30 years) whereas male patients peaked at a higher age (61-70 years). Most (92%, 105 of 114) patients had positive anti-acetylcholine receptor antibodies. Five patients were also tested for anti-muscle-specific tyrosine kinase antibodies, with two showing positivity. Thymectomy was performed in 62 (52%) patients, of which 30 had thymoma, 16 had thymic hyperplasia, 7 had an involuted thymus, and 6 had a normal thymus. There were significantly more female patients (68% vs. 45%, p=0.011) with early-onset disease (<50 years old) and thymic hyperplasia (33% vs. 0%, p<0.025). Most (71%) of the patients had a good outcome based on the Myasthenia Gravis Foundation of America postintervention status. GMG patients with early-onset disease had a significantly better outcome than patients with a late onset in univariate (58% vs. 37%, p=0.041) and multivariate (odds ratio=4.68, 95% confidence interval=1.17-18.64, p=0.029) analyses.

CONCLUSIONS

Female patients with early-onset MG and thymic hyperplasia had significantly better outcomes, but only early-onset disease was independently associated with a good outcome. These findings are comparable with those of other studies.

Drug Use Patterns in Myasthenia Gravis: A Real-World Population-Based Cohort Study in Italy

Background: In the context of a comparative study of efficacy and safety of drugs used in rare neuromuscular and neurodegenerative diseases (CAESAR-call AIFA_FV_2012-13-14), we assessed the use patterns of drugs indicated for myasthenia gravis (MG). Methods: A retrospective cohort study was conducted based on administrative healthcare data. For a cohort of MG patients, prevalent and incident use of pyridostigmine (Py) and other indicated drugs in the first year after case identification was evaluated. Prevalent combined use of major therapies (azathioprine (Az), prednisone (Pr), vitamin D (Vd)) stratified by Py use was assessed, and a comparison between therapies at the time of MG identification and during the first year of follow-up was performed. Results: We included 2369 MG patients between 2013 and 2019. Among them, prevalent and incident Py users were 38.4% and 22.0%, respectively. In the first year of follow-up, the use of Pr was observed in 74.5% of Py prevalent users and in 82.0% of Py incident users, respectively; the use of Az was observed in 24.9% and 23.0%, respectively; and the use of Vd was observed in 53.3% and 48.2%, respectively. Among 910 Py prevalent users, 13.1% also used Az, Pr, and Vd, while 15.3% used none of these. Among 938 non-Py users, 2.7% used Az, Pr, and Vd, while 53.8% used none of these. During the first year, an increase in combined therapies was evident in incident Py users. Conclusions: Our results suggest that, for some MG patients, there may be a need for treatments that combine a rapid onset of benefit with long-term and consistent disease control. These issues may be addressed by the new treatments currently being developed. To date, more studies are needed to address the heterogeneity, quality, and generalizability of the existing data and to evaluate patterns of use, efficacy, and safety of new or emerging therapies for MG.

The Influence of Loneliness and Anxiety Levels on MG-Specific Quality of Life in Patients with Myasthenia Gravis during the COVID-19 Pandemic

BACKGROUND

Myasthenia gravis (MG) is one of the most common autoimmune diseases and can occur at any age. The study aimed to evaluate the influence of loneliness and anxiety levels on MG-specific quality of life in patients with myasthenia gravis during the COVID-19.

METHODS

This was a cross sectional study and the population consisted of patients with MG throughout Turkey between August 1 and October 31, 2021. The study was completed with 149 patients who met the inclusion criteria and agreed to participate in the research.

RESULTS

The mean MG-specific quality of life score was 44.15 ± 13.77, the mean UCLA loneliness scale was 56.13 ± 11.55, and the mean Beck Anxiety Inventory score was 24.63 ± 13.78. There was a moderately positive linear relationship between the participants' MG-specific quality of life (r = 0.589; p < 0.001) and the Beck Anxiety Inventory, and there was a weak negative linear relationship with the UCLA loneliness scale (r = 0.323; p < 0.001). The variables affecting the MG-specific quality of life were the following: anxiety, loneliness, employment status, income level, symptom levels, and having another chronic disease; a multiple regression model was created with these variables, and it was observed that anxiety and loneliness affected participants' MG-specific quality of life. The variables in the model explained 52.9% of the MG-specific quality of life, and the model was statistically significant (p < 0.001).

CONCLUSION

The study determined that the participants had intense loneliness, moderate anxiety, and a moderate MG-specific quality of life. The participants' MG-specific quality of life has decreased as their anxiety has increased, and the participants' MG-specific quality of life has increased as their loneliness has increased.

Cooccurrence of Myasthenia Gravis and Epilepsy: A Case Report

Myasthenia gravis (MG) is an autoimmune disease characterized by weakness and rapid fatigue of the voluntary muscles. Epilepsy is a neurological disorder marked by recurrent, unprovoked seizures. We present a case of a 34-year-old woman with idiopathic generalized epilepsy who developed MG at 33. While the relationship between MG and epilepsy remains unclear, it is known that antiepileptic drugs can exacerbate MG. The rarity of this association suggests a need for cautious selection of antiepileptic treatments to avoid worsening either condition.

The Neurological Implications of COVID-19: A Comprehensive Narrative Review

The COVID-19 pandemic caused by the coronavirus SARS-CoV-2 revealed a huge number of problems as well as discoveries in medicine, notably, regarding the effects of the virus on the central nervous system (CNS) and peripheral nervous system (PNS). This paper is a narrative review that takes a deep dive into the complex interactions between COVID-19 and the NS. Therefore, this paper explains the broad range of neurological manifestations and neurodegenerative diseases caused by the virus. It carefully considers the routes through which SARS-CoV-2 reaches the NS, including the olfactory system and of course, the hematogenous route, which are also covered when discussing the virus's direct and indirect mechanisms of neuropathogenesis. Besides neurological pathologies such as stroke, encephalitis, Guillain-Barré syndrome, Parkinson's disease, and multiple sclerosis, the focus area is also given to the challenges of making diagnosis, treatment, and management of these conditions during the pandemic. The review also examines the strategic and interventional approaches utilized to prevent these disorders, as well as the ACE2 receptors implicated in the mediation of neurological effects caused by COVID-19. This detailed overview, which combines research outputs with case data, is directed at tackling this pandemic challenge, with a view toward better patient care and outcomes in the future.

The efficacy and safety of FcRn inhibitors in patients with myasthenia gravis: a systematic review and meta-analysis

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disease that causes local or generalized muscle weakness. Complement inhibitors and targeting of the neonatal Fc receptor (FcRn) to block IgG cycling are two novel and successful mechanisms.

METHODS

PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov were systematically searched to identify relevant studies published before May 18, 2023. Review Manager 5.3 software was used to assess the data.

RESULTS

We pooled 532 participants from six randomized controlled trials (RCTs). Compared to the placebo, the FcRn inhibitors were more efficacy in Myasthenia Gravis Activities of Daily Living (MG-ADL) (MD = - 1.69 [- 2.35, - 1.03], P < 0.00001), MG-ADL responder (RR = 2.01 [1.62, 2.48], P < 0.00001), Quantitative Myasthenia Gravis (QMG) (MD = - 2.45 [- 4.35, - 0.55], P = 0.01), Myasthenia Gravis Composite (MGC) (MD = - 2.97 [- 4.27, - 1.67], P < 0.00001), 15-item revised version of the Myasthenia Gravis Quality of Life (MGQoL15r) (MD = - 2.52 [- 3.54, - 1.50], P < 0.00001), without increasing the risk of safety. The subgroup analysis showed that efgartigimod was more effective than placebo in MG-ADL responders. Rozanolixizumab was more effective than the placebo except in QMG, and batoclimab was more effective than the placebo except in MG-ADL responder. Nipocalizumab did not show satisfactory efficacy in all outcomes. With the exception of rozanolixizumab, all drugs showed non-inferior safety profiles to placebo.

CONCLUSION

FcRn inhibitors have good efficacy and safety in patients with MG. Among them, efgartigimod and nipocalimab were effective without causing an increased safety risk. Rozanolixizumab, despite its superior efficacy, caused an increased incidence of adverse events. Current evidence does not suggest that nipocalimab is effective in patients with MG.

Lady With the Blue Hair: An Atypical Cause of Myasthenic Crisis

A myasthenic crisis denotes a severe exacerbation of myasthenia gravis, leading a patient to enter a life-threatening state due to progressing muscle weakness that ultimately results in respiratory failure. A crisis can require intubation, mechanical ventilation, and additional critical care to prevent further decompensation and potentially death. Numerous well-documented precipitating factors exist, such as infections, surgery, stress, and various medications. We present the case of a 43-year-old woman recently diagnosed with myasthenia gravis who has experienced two myasthenic crises since diagnosis without evident triggers such as surgery, changes in medication, or infection. Following an unremarkable initial diagnostic test and continued treatment for the crisis, we sought additional information from the patient's family member at the bedside. We were informed that two weeks prior to both times of crisis with intubation, the patient had dyed her hair blue. The common chemical component in the two different hair dyes used was methylisothiazolinone, which is suspected to have contributed to the exacerbation of the patient's myasthenia gravis. As more evidence for new precipitating factors of myasthenic crises develops, it is crucial for physicians to quickly identify signs and symptoms of a crisis so appropriate intervention can occur in a time-sensitive manner. In addition, myasthenia gravis patients should be made aware to be cautious of precipitating factors of a crisis, including but not limited to new beauty products.

A retrospective observational study on characteristics, treatment patterns, and healthcare resource use of patients with myasthenia gravis in England

Background

There are limited data on the real-world healthcare resource use (HCRU) and management costs of myasthenia gravis (MG) in England.

Objective

This study aims to assess the burden of disease for patients with MG in England.

Design

A retrospective, observational cohort study of adult patients diagnosed with MG, using data from the Hospital Episode Statistics data warehouse.

Methods

Patients with a first-ever recorded diagnosis of MG between 30 June 2015 and 30 June 2020 were followed up until 30 June 2021 or death, whichever occurred first. Post-diagnosis patient characteristics, treatment patterns, HCRU, and costs were described. Costs were evaluated using National Health Service reference costs.

Results

A total of 9087 patients with a median follow-up time of 2.9 years (range, 1.7-4.3 years) were included. The mean age at diagnosis was 66.5 years and 53% of the patients were male. A large proportion of patients (72.8%) were admitted as inpatients during follow-up with a mean number of 1.3 admissions. Patients hospitalized for MG-related complications spent a mean of 9.7 days per patient-year in the hospital. During follow-up, 599 (6.6% of the total cohort) and 163 (1.8%) patients had a record of rescue therapy with intravenous immunoglobulin (IVIg) and plasma exchange (PLEX), respectively. Rituximab was administered to 81 (0.9%) patients and 268 (2.9%) patients underwent thymectomy. In those patients receiving rescue therapy or rituximab, >10% received at least three cycles of the same treatment. The average annual cost of hospital admissions across all patients treated with IVIg, PLEX, and rituximab were £907,072, £689,979, and £146,726, respectively.

Conclusion

A majority of MG patients required hospitalization or accident and emergency attendance, resulting in high HCRU and costs. A subset of patients required rescue therapy (including IVIg and PLEX), rituximab administration, ventilation, or thymectomy.

Advances in Understanding and Managing Myasthenia Gravis: Current Trends and Future Directions

Myasthenia gravis (MG) is an autoimmune illness characterized by autoantibodies against the acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK), and an increasing number of extra postsynaptic proteins. Pathogenic autoantibodies reduce the number of functional AChRs in the neuromuscular junction's (NMJ) muscle end plate. The cause of the autoimmune response is unknown, but thymic abnormalities and immune regulatory deficiencies are significant. The disease's incidence is likely influenced by genetic predisposition, with sex hormones and exercise playing a role. MG can affect any age, race, or gender and can be caused by any stressor, with infections being the most frequent cause. Treatment focuses on airway support and the triggering incident. MG is a rare autoimmune disease causing fatigue-inducing weakness in the axial, respiratory, leg, and bulbar muscles. Initially affecting the eyes, most MG patients experience at least one worsening symptom during their illness. The disease is mainly caused by antibodies against the AChR, dependence on the immune system within cells, and engagement of the complement system. The complement system plays a significant role in MG, and complement inhibition can both prevent the onset and slow its development. Ocular MG affects around 15% of people, with most patients having blocking antibodies against the cholinergic receptor. There may be correlations between thymoma and other autoimmune conditions, especially thyroid illness. Treatment and management for MG involve removing autoantibodies from circulation or blocking effector mechanisms using techniques such as complement inhibition, plasmapheresis, and B-cell elimination.

Pediatric Ocular Myasthenia Gravis: Single-Center Experience

BACKGROUND

Currently, there is no universally accepted standard treatment for ocular myasthenia gravis (OMG) in children. We aimed to investigate the possible proper regimens and timing of treatment for pediatric OMG cases based on the clinical manifestations: OMG with ptosis only and OMG with other features.

METHODS

One hundred and forty two OMG cases attended at the Department of Pediatrics, Xiangya Hospital, Central South University, from 2010 to 2019 were included, and information from medical records was reviewed and recorded. Comparisons of clinical characteristics between patients with OMG with ptosis only and patients with OMG with other features as well as between patients treated with glucocorticoid (GC) within or after six months from disease onset were performed.

RESULTS

OMG with other features constituted about 54.9% of the cases, and 66.2% of the patients achieved optimal outcome. Patients with OMG with ptosis only responded to pyridostigmine alone more than patients with OMG with other features who required several therapies (P < 0.001). Patients with OMG with ptosis only had a larger proportion of optimal outcome than the patients with OMG with other features (P = 0.002), and the difference remained significant even when the individual outcome groups were compared (P < 0.001). Patients who received GC within six months had a greater proportion of optimal outcome than those who received it after six months (P < 0.001).

CONCLUSIONS

Although OMG with other features is a more common subtype of OMG, it is also more severe than OMG with ptosis only. An earlier addition of GC leads to optimal outcome.

A Male Patient Presents With Isolated Abducens Nerve Palsy: An Atypical Presentation of Ocular Myasthenia Gravis

Myasthenia gravis is an autoimmune disease of the neuromuscular junction caused by autoantibodies directed against the acetylcholine receptors. It presents with skeletal muscle weakness, often initially presenting with ocular symptoms such as ptosis and diplopia. When myasthenia gravis is isolated to only ocular symptoms, it is referred to as ocular myasthenia gravis (OMG). Here, we present an atypical initial presentation of OMG in a 68-year-old male patient presenting with isolated abducens nerve palsy at the initial onset. With this case report, we highlight the importance of a thorough history and clinical assessment necessary for a timely diagnosis of OMG in patients who present with isolated abducens nerve palsy.

The impact of myasthenia gravis severity on work and daily activities

INTRODUCTION/AIMS

People with myasthenia gravis (MG) experience impaired quality of life. However, the impact of MG symptoms on work productivity has not been well-studied. We aimed to evaluate this impact and to examine associations between disease severity and the degree of impairment.

METHODS

Data were drawn from the Adelphi MG Disease-Specific Programme™, a multinational (USA, France, Germany, Italy, Spain, UK) survey completed by physicians and their patients with MG in 2020. Patient-reported measures included the Work Productivity and Activity Impairment (WPAI): Specific Health Problem questionnaire.

RESULTS

The WPAI questionnaire was completed by 330 patients. Among those currently employed, the mean percentage of work time missed (absenteeism) was 13.3% (N = 116), percentage impairment of productivity at work (presenteeism) was 26.7% (N = 121), and overall work impairment was 30.0% (N = 110). Across all patients, impairment of non-work-related activities due to health problems (ADL impairment) was 39.2% (N = 330). Regression analysis indicated that impairment differed according to MG Foundation of America (MGFA) class (p = .0147, p < .0001, p < .0001 and p < .0001 for absenteeism, presenteeism, overall work impairment and ADL impairment, respectively). Being MGFA class III/IV was a predictor of presenteeism, overall work impairment and ADL impairment in a predictor model.

DISCUSSION

Patients with MG experience substantial work impairment particularly those with more severe symptoms, highlighting an important way in which patient quality of life is negatively affected. More effective treatment strategies would enable patients to lead more productive lives and could impact decisions relating to work and career.

Study on the clinical and electrophysiological characteristics of nerve function in myasthenia gravis patients in Vietnam

Background

In Vietnam, there is limited research on the role of nerve conduction in myasthenia gravis and its association with clinical features.

Objective

This study aims to describe the electrophysiological features in patients with myasthenia gravis.

Methods

This descriptive study was conducted from September 2019 to December 2021. The study included 33 myasthenia gravis patients who sought medical consultation or received inpatient treatment during this period. The Myasthenia Gravis Foundation of America classifies myasthenia gravis into five groups: I, IIa, IIb, IIIa, IIIb, IVa, IVb, and V. Notably, Group I involves pure ocular weakness, whereas Group a primarily impacts limb and axial muscles, and Group b mainly affects bulbar and respiratory muscles.

Results

The study revealed that motor and sensory nerve conduction in the upper and lower limbs were within normal limits for the patient group under evaluation. Repetitive nerve stimulation testing at a frequency of 3 Hz showed positive results in 66.7% of myasthenia gravis patients. Myasthenia gravis patients displayed distinct clinical symptoms, with ptosis being the most common (87.9%). Myasthenia Gravis Foundation of America classification indicated the highest proportion in subgroup IIa (24.2%), with myasthenia gravis predominating in limb and axial muscles (Group a) observed in 51.5% of cases. Needle electromyography showed no abnormalities in myasthenia gravis patients. There was an association between acetylcholine receptor antibody titers and the results of the 3 Hz repetitive nerve stimulation test in myasthenia gravis patients, with a significance of p = 0.002.

Conclusion

Nerve conduction studies should be performed in patients with suspected neuromuscular disorders to aid in differential diagnosis and definitive diagnosis of myasthenia gravis.

Therapeutic Effect and Side Effects of Pharmacotherapy in Patients With Parkinson Disease and Myasthenia Gravis: A Systematic Review of Case Reports and Case Series Studies

PURPOSE

The co-existence of Parkinson disease (PD) and myasthenia gravis (MG) in an individual should be exceptionally rare. The purpose of this study was to systematically review the current literature regarding the therapeutic effect and side effects of pharmacotherapy on patients with PD and MG.

METHODS

Five bioscience and engineering databases (MEDLINE via PubMed, Cochrane Library, Scopus, EMBASE, and China National Knowledge Infrastructure) were searched from inception through February 21, 2022. Case reports and case series studies investigating pharmacotherapy in patients with PD and MG were included. Procedures were followed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The methodologic quality of included studies was evaluated by using the National Institutes of Health Quality Assessment Tool for Case Series Studies.

FINDINGS

Sixteen case reports and 5 case series studies with 32 participants met the inclusion criteria. Eight studies were rated as good quality, 10 were fair quality, and 3 were poor quality. The side effects of pharmacotherapy for PD or MG led to another disease, indicating an imbalance between dopamine and acetylcholine within human bodies.

IMPLICATIONS

When treating a patient who has PD or MG, health providers should be cautious about the occurrence of another disease. Timely treatment must rely on monitoring new symptoms as soon as the pharmacotherapy for PD or MG is initiated. Physical therapy may be helpful in decreasing the side effects of pharmacotherapy in patients with PD and MG. A new treatment pattern of pharmacotherapy + physical therapy for patients with PD and MG warrants further research. International Prospective Register of Systematic Reviews identifier: CRD42022308066.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Batoclimab as induction and maintenance therapy in patients with myasthenia gravis: rationale and study design of a phase 3 clinical trial

Introduction

Batoclimab, a fully human monoclonal antibody that inhibits the neonatal fragment crystallisable receptor, has shown promising phase 2 clinical trial results in patients with generalised myasthenia gravis (gMG).

Methods and analysis

In this phase 3, randomised, quadruple-blind, placebo-controlled study, adults with gMG will be randomised 1:1:1 to induction therapy with batoclimab 680 mg, batoclimab 340 mg, or placebo, administered once weekly (QW) for 12 weeks as a subcutaneous injection. The primary endpoint is the change from baseline to week 12 on the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Batoclimab-treated patients achieving a ≥2-point improvement from baseline on MG-ADL at week 10 or week 12 will be re-randomised to maintenance treatment with batoclimab 340 mg QW, batoclimab 340 mg every other week (Q2W), or placebo for 12 weeks; batoclimab-treated patients with a <2-point improvement at week 10 and week 12 will be switched to placebo for the maintenance period and discontinued thereafter. Placebo-treated patients from the induction period will be re-randomised to batoclimab 340 mg QW or Q2W in the maintenance period. All patients who complete the maintenance period and achieve a ≥2-point improvement from baseline in MG-ADL during ≥1 of the final 2 visits of the induction and/or maintenance periods will continue their current batoclimab dose (or switch to batoclimab 340 mg QW for those on placebo) for a 52-week long-term extension (LTE-1). Patients who complete LTE-1 may enter a second, optional 52-week LTE (LTE-2).

Ethics and dissemination

This trial is being conducted in accordance with the International Council for Harmonisation Guideline for Good Clinical Practice, the Declaration of Helsinki, and each site's Institutional Review Board/Independent Ethics Committee. All patients must provide written informed consent. Results from this study will be published in peer-reviewed journals and presented at national and global conferences.

Trial registration number

NCT05403541.

Effects of acupuncture treatment for myasthenia gravis: A systematic review and meta-analysis

BACKGROUND

Randomized controlled trials (RCTs) of acupuncture for myasthenia gravis (MG) were searched and the efficacy of acupuncture in the treatment of MG was evaluated by meta-analysis.

METHODS

We searched for RCTs in six main electronic databases, and collected RCTs of acupuncture treatment for MG from database creation to 28 February 2023. The main outcome was the effective rate and the secondary outcome was the Traditional Chinese Medicine (TCM) relative clinical score, absolute clinical score (ACS) of MG, Quantitive myasthenia gravis score (QMG), quality of life, and adverse events. Odds ratios (ORs) and weighted mean differences (WMD) and 95% confidence intervals (CI) were used to assess pooled effect estimates using Review Manager software.

RESULTS

A total of 14 RCTs were included. Meta-analysis showed that the effective rate in the acupuncture group was significantly improved compared with conventional Western medicine alone [OR = 4.28, 95% CI (2.95, 6, 22), P<0.005]. The pooled WMDs revealed that TCM relative clinical score [WMD = -2.22, 95% CI = (-2.53, -1.90), P<0.005], ACS of MG [WMD = -3.14, 95% CI = (-3.67, -2.62), P<0.005], and QMG [WMD = -0.88, 95% CI = (-1.46, -0.29), P<0.005] in the acupuncture group was lower than the control group. Adverse reactions related to acupuncture and quality of life were less mentioned among included RCTs.

CONCLUSION

This meta-analysis demonstrated that acupuncture as an auxiliary may play a positive role in treating MG. It can improve the effective rate of treatment, and reduce TCM relative clinical score, ACS of MG, and QMG. However, the quality of included studies was generally low and caution should be exercised when considering this treatment option. In the future, more rigorous study designs and high-quality RCTs are needed to verify the efficacy of acupuncture in the treatment of MG, because the results of high-quality RCTs are more reliable and accurate.

The influence of symptom severity and fatigue on sleep quality in patients with myasthenia gravis

INTRODUCTION

Myasthenia gravis is a rare and chronic autoimmune disease. The study aimed to evaluate the influence of symptom severity and fatigue on sleep quality in patients with myasthenia gravis.

METHODS

This was a cross-sectional study, and the population consisted of patients with MG throughout Turkey. The study was completed with 163 patients on 1 April and 31 July 2022.

RESULTS

 It was found that the mean Myasthenia Gravis-Activities of Daily Living Scale score was 6.32 ± 3.9, the Fatigue Severity Scale score was 37.01 ± 23.26, and the total Pittsburgh Sleep Quality Index score was 9.04 ± 2.69. The variables affecting the Pittsburgh Sleep Quality Index scores were age, Body Mass Index, Fatigue Severity Scale ≥ 4, Myasthenia Gravis-Activities of Daily Living Scale ≥ 5.5, duration of diagnosis, and income level; a multiple regression model was created with these variables, and the variables in the resulting model explained 26.4% of the Pittsburgh Sleep Quality Index scores. In addition, those with clinically significant symptom severity (MG-ADL ≥5.5) in daily living and those with severe fatigue (FSS ≥4) explained 17.2% of the PSQI scores, and the model was statistically significant (p < 0.001).

CONCLUSION

The study determined that the participants had clinically significant symptom severity in daily living, severe fatigue, and poor sleep quality. The participants with clinically significant severe symptoms in daily living and fatigue had higher sleep disturbances, daytime dysfunction, and poor sleep quality.

Depression: A Contributing Factor to the Clinical Course in Myasthenia Gravis Patients

Background and Objectives: The association between myasthenia gravis (MG) and depression is intricate and characterized by bidirectional causality. In this regard, MG can be a contributing factor to depression and, conversely, depression may worsen the symptoms of MG. This study aimed to identify any differences in the progression of the disease among patients with MG who were also diagnosed with depression as compared to those without depression. Our hypothesis focused on the theory that patients with more severe MG symptoms may have a higher likelihood of suffering depression at the same time. Materials and Methods: One hundred twenty-two male and female patients (N = 122) aged over 18 with a confirmed diagnosis of autoimmune MG who were admitted to the Neurology II department of Myasthenia Gravis, Clinical Institute Fundeni in Bucharest between January 2019 and December 2020, were included in the study. Patients were assessed at baseline and after six months. The psychiatric assessment of the patients included the Hamilton Depression Rating Scale-17 items (HAM-D), and neurological status was determined with two outcome measures: Quantitative Myasthenia Gravis (QMG) and Myasthenia Gravis Activities of Daily Life (MG-ADL). The patients were divided into two distinct groups as follows: group MG w/dep, which comprised 49 MG patients diagnosed with depressive disorder who were also currently receiving antidepressant medication, and group MG w/o dep, which consisted of 73 patients who did not have depression. Results: In our study, 40.16% of the myasthenia gravis (MG) patients exhibited a comorbid diagnosis of depression. Among the MG patients receiving antidepressant treatment, baseline assessments revealed a mean MG-ADL score of 7.73 (SD = 5.05), an average QMG score of 18.40 (SD = 8.61), and a mean Ham-D score of 21.53 (SD = 7.49). After a six-month period, a statistically significant decrease was observed in the MG-ADL (2.92, SD = 1.82), QMG (7.15, SD = 4.46), and Ham-D scores (11.16, SD = 7.49) (p < 0.0001). These results suggest a significant correlation between MG severity and elevated HAM-D depression scores. Regarding the MG treatment in the group with depression, at baseline, the mean dose of oral corticosteroids was 45.10 mg (SD = 16.60). Regarding the treatment with pyridostigmine, patients with depression and undergoing antidepressant treatment remained with an increased need for pyridostigmine, 144.49 mg (SD = 51.84), compared to those in the group without depression, 107.67 mg (SD = 55.64, p < 0.001). Conclusions: Our investigation confirms that the occurrence of depressive symptoms is significantly widespread among individuals diagnosed with MG. Disease severity, along with younger age and higher doses of cortisone, is a significant factor associated with depression in patients with MG. Substantial reductions in MG-ADL and QMG scores were observed within each group after six months, highlighting the effectiveness of MG management. The findings suggest that addressing depressive symptoms in MG patients, in addition to standard MG management, can lead to improved clinical outcomes.

Myasthenia Gravis: A Systematic Review

Myasthenia gravis (MG), a rare disease, is the most common neuromuscular junction problem. It's the quintessential autoimmune disease with ocular, bulbar, respiratory, axial, and limb muscles exhibiting a typical fatigable weakening due to the development of antibodies against the acetylcholine receptor (AChR). Infections, stress, surgeries, thymus gland anomalies, and pharmaceutical side effects can also cause it. Ocular symptoms are initially experienced by most of the sufferers. The majority of the sufferers will go through at least one episode of symptom exacerbation during their illness. The immune system in MG interferes with nerve-muscle communication, causing muscles to become weak and tired quickly. The actual cause is not yet known, but a problem in the thymus gland may be the cause. In a person suffering from this disease, the size of the thymus becomes larger than normal, which is also called thymic hyperplasia. It is more common for women to have early-onset MG (EOMG) than for males to have late-onset MG (LOMG). Merely clinical evidence, encompassing the patients' medical history and physical indications of fluctuating muscle weakness in a specific region, is utilized to diagnose MG. Complementary diagnostic procedures and lab techniques aid in confirming the synaptic dysfunction and characterizing its kind and degree. Early diagnosis and the availability of effective treatments have reduced the burden of severe impairment and high mortality previously associated with MG. Current immunomodulation-based therapies come with side effects brought on by persistent immune suppression. Improved knowledge of this relatively uncommon but curable condition is required among primary carers. The objective of this review is to provide information about MG and to help people recognize its symptoms and start treatment without panic so that the progression of this disease can be stopped and complications can be avoided.

Association between COVID-19 vaccination and myasthenia gravis: A population-based, nested case-control study

BACKGROUND

Existing data regarding the link between COVID-19 vaccine and myasthenia gravis (MG) are scarce. We aimed to assess the association between Pfizer-BioNTech vaccine with both new-onset MG and MG exacerbation.

METHODS

For the first aim, we conducted a nested case-control study in a cohort of 3,052,467 adults, without a diagnosis of MG, from the largest healthcare provider in Israel. Subjects were followed from January 1, 2021 until June 30, 2022 for the occurrence of MG. Ten randomly selected controls were matched to each case of new-onset MG on age and sex. For the second aim, a nested case-control study was conducted in a cohort of 1446 MG patients. Four randomly selected MG patients (controls) were matched to each case of MG exacerbation. Exposure to COVID-19 vaccine in the prior 4 weeks was assessed in cases and controls.

RESULTS

Overall, 332 patients had new-onset MG and were matched with 3320 controls. Multivariable conditional logistic regression models showed that the odds ratio (OR) for new-onset MG, associated with COVID-19 vaccine, was 1.14 (95% CI 0.73-1.78). The results were consistent in sensitivity analysis that used more stringent criteria to define MG. Overall, 62 patients with MG exacerbation were matched to 248 MG controls. The multivariable OR for MG exacerbation, associated with COVID-19 vaccine, was 1.35 (95% CI 0.37-4.89). All results were similar when the prior exposure to COVID-19 vaccine was extended to 8 weeks.

CONCLUSION

This study suggests that Pfizer-BioNTech vaccine is not associated with increased risk of new-onset nor exacerbation of MG.

Efficacy and safety of the innovative monoclonal antibodies in adults with generalized myasthenia gravis: a Bayesian network analysis

Background

A series of clinical trials support the effectiveness of monoclonal antibodies for generalized myasthenia gravis (MG) compared to the placebo, but the priority among drugs remains unclear. Therefore, we conduct a frequentist network meta-analysis (NMA) to compare the relative effects of different drugs for generalized MG.

Methods

PubMed, Embase, Cochrane Library, and clinicaltrials.gov were systematically searched for eligible studies up to 1 June 2023. The primary outcome was efficacy (Myasthenia Gravis Activities of Daily Living [MG-ADL] score and Quantitative Myasthenia Gravis [QMG] score) and safety (adverse events [AEs]). Mean difference (MD) and risk ratio (RR) with their 95% credible intervals (95%CrIs) were used to show the effect size of continuous and categorical variables, respectively. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results

Thirteen studies involving 1167 individuals were identified for NMA. For efficacy outcomes, belimumab, efgartigimod, mezagitamab 600mg, and nipocalimab 60mg/kg were inferior to rozanolixzumab 7mg/kg (MD ranged from 2 to 3.69) and rozanolixzumab 10mg/kg (MD ranged from 2.04 to 3.72) in MG-ADL score, and rozanolixzumab had the highest rank probability (83%) according to the subjective surface under the curve ranking area (SUCRA). For QMG score, batoclimab 340mg (MD ranged from 4.32 to 8.52) and batoclimab 680mg (MD ranged from 4.11 to 9.31) were more effective than placebo and other monoclonal antibodies except for rozanolixzumab, with the highest SUCRA value (93% and 97% respectively). For safety outcomes, belimumab achieved the highest SUCRA value (89.8%) with significant statistical difference compared to rozanolixzumab 7mg/kg (RR 0.08, 95%CrI 0.01 to 0.94) and rozanolixzumab 10mg/kg (RR 0.08, 95%CrI 0.01 to 0.86).

Conclusion

While all monoclonal antibodies were superior to the placebo, rozanolixzumab and batoclimab might be the most effective for generalized MG. However, rozanolixzumab was associated with higher incidence of AEs. Given the limitations inherent in indirect comparisons, further head-to-head and extensive observational studies are necessary to confirm our findings.

Systematic review registration

https://inplasy.com/?s=202370112, identifier 202370112.

Machine learning strategy for identifying altered gut microbiomes for diagnostic screening in myasthenia gravis

Myasthenia gravis (MG) is a neuromuscular junction disease with a complex pathophysiology and clinical variation for which no clear biomarker has been discovered. We hypothesized that because changes in gut microbiome composition often occur in autoimmune diseases, the gut microbiome structures of patients with MG would differ from those without, and supervised machine learning (ML) analysis strategy could be trained using data from gut microbiota for diagnostic screening of MG. Genomic DNA from the stool samples of MG and those without were collected and established a sequencing library by constructing amplicon sequence variants (ASVs) and completing taxonomic classification of each representative DNA sequence. Four ML methods, namely least absolute shrinkage and selection operator, extreme gradient boosting (XGBoost), random forest, and classification and regression trees with nested leave-one-out cross-validation were trained using ASV taxon-based data and full ASV-based data to identify key ASVs in each data set. The results revealed XGBoost to have the best predicted performance. Overlapping key features extracted when XGBoost was trained using the full ASV-based and ASV taxon-based data were identified, and 31 high-importance ASVs (HIASVs) were obtained, assigned importance scores, and ranked. The most significant difference observed was in the abundance of bacteria in the Lachnospiraceae and Ruminococcaceae families. The 31 HIASVs were used to train the XGBoost algorithm to differentiate individuals with and without MG. The model had high diagnostic classification power and could accurately predict and identify patients with MG. In addition, the abundance of Lachnospiraceae was associated with limb weakness severity. In this study, we discovered that the composition of gut microbiomes differed between MG and non-MG subjects. In addition, the proposed XGBoost model trained using 31 HIASVs had the most favorable performance with respect to analyzing gut microbiomes. These HIASVs selected by the ML model may serve as biomarkers for clinical use and mechanistic study in the future. Our proposed ML model can identify several taxonomic markers and effectively discriminate patients with MG from those without with a high accuracy, the ML strategy can be applied as a benchmark to conduct noninvasive screening of MG.

Diagnosis and therapy of myasthenia gravis-the patients' perspective: a cross-sectional study

The survey aimed to explore patients' perspectives with myasthenia gravis (MG) toward the diagnosis made and the therapy used to treat MG. The survey was conducted with a quantitative method, using the CAWI technique. A total of 321 people participated in the survey. More than half of the respondents (56.4%) had suffered from MG for less than 10 years. In three out of 10 cases (30.9%), the diagnosis of MG lasted 3 years or longer. The diagnostic delay was significantly longer in female respondents than in the males (p = 0.029). Cholinergic drugs were used in 92.9% of cases initially, and as maintenance therapy in 84.3% of cases. Corticosteroids were used in initiating therapy (45.8%) and as maintenance therapy (46.4%). One in four respondents (25.5%) reported experiencing very strong and strong side effects after using steroids. The side effects from steroid therapy very strong or strong affected overall physical health in 55.9% of respondents, very strong or strong affected self-acceptance in 52%, to a very large or large extent on mental health in 47.1%, and to a very strong or strong extent influenced the performance of daily activities in 28.2%. More than half of the respondents (57.0%) had had a thymectomy. Seven out of 10 respondents (72.0%) declared that the therapy they were on at the time of the survey allowed them (to varying degrees) to control their course of MG. Low therapy acceptance and less well controlled MG was associated with a preference for non-tablet therapies (p = 0.045). Regular follow-up and cooperation with the specialist health care system should improve MG symptoms, activities of daily living, and quality of life.

Neuromuscular fatigue in autoimmune myasthenia gravis: A cross-sectional study

OBJECTIVES

To investigate the presence of increased neuromuscular fatigue (NMF) in individuals with myasthenia gravis (IwMG), compared to healthy controls. A secondary aim was to assess associations between NMF, strength and perceived health-related quality of life (HRQoL) and symptom severity in IwMG.

METHODS

In this cross-sectional study, we assessed NMF using classical myoelectrical indicators (root mean square: RMS, mean power frequency: MPF) obtained from surface electromyography (sEMG) during a sustained submaximal isometric contraction of the right Biceps Brachii and the right Vastus Lateralis and by evaluating the post-effort decline in peak torque following a fatiguing task consisting of a 40-second sustained isometric contraction. Relationships with MG-specific clinical scores (Myasthenia Muscle Score for symptom severity, MGQOL-15-F for HRQoL) were investigated.

RESULTS

Forty-one females with MG were compared to 18 control females of similar age. IwMG demonstrated reduced strength in both muscle groups, compared to control subjects. In both populations and both limbs, NMF was demonstrated by an increase in RMS and a decrease in MPF. However, IwMG did not demonstrate greater NMF based on these myoelectrical indicators nor based on post-effort peak torque decline.

DISCUSSION

Despite a decrease in baseline strength, IwMG did not display greater NMF in this specific experimental paradigm. This cohort consisted of individuals with mild-to-moderately severe MG which was well-controlled and stable. Further studies are warranted to identify simple and reliable methods to measure NMF in MG and to understand the relationship between NMF and perceived fatigue in activities of daily living for IwMG.

Immunotherapies in MuSK-positive Myasthenia Gravis; an IgG4 antibody-mediated disease

Muscle-specific kinase (MuSK) Myasthenia Gravis (MG) represents a prototypical antibody-mediated disease characterized by predominantly focal muscle weakness (neck, facial, and bulbar muscles) and fatigability. The pathogenic antibodies mostly belong to the immunoglobulin subclass (Ig)G4, a feature which attributes them their specific properties and pathogenic profile. On the other hand, acetylcholine receptor (AChR) MG, the most prevalent form of MG, is characterized by immunoglobulin (Ig)G1 and IgG3 antibodies to the AChR. IgG4 class autoantibodies are impotent to fix complement and only weakly bind Fc-receptors expressed on immune cells and exert their pathogenicity via interfering with the interaction between their targets and binding partners (e.g. between MuSK and LRP4). Cardinal differences between AChR and MuSK-MG are the thymus involvement (not prominent in MuSK-MG), the distinct HLA alleles, and core immunopathological patterns of pathology in neuromuscular junction, structure, and function. In MuSK-MG, classical treatment options are usually less effective (e.g. IVIG) with the need for prolonged and high doses of steroids difficult to be tapered to control symptoms. Exceptional clinical response to plasmapheresis and rituximab has been particularly observed in these patients. Reduction of antibody titers follows the clinical efficacy of anti-CD20 therapies, a feature implying the role of short-lived plasma cells (SLPB) in autoantibody production. Novel therapeutic monoclonal against B cells at different stages of their maturation (like plasmablasts), or against molecules involved in B cell activation, represent promising therapeutic targets. A revolution in autoantibody-mediated diseases is pharmacological interference with the neonatal Fc receptor, leading to a rapid reduction of circulating IgGs (including autoantibodies), an approach already suitable for AChR-MG and promising for MuSK-MG. New precision medicine approaches involve Chimeric autoantibody receptor T (CAAR-T) cells that are engineered to target antigen-specific B cells in MuSK-MG and represent a milestone in the development of targeted immunotherapies. This review aims to provide a detailed update on the pathomechanisms involved in MuSK-MG (cellular and humoral aberrations), fostering the understanding of the latest indications regarding the efficacy of different treatment strategies.

Population PK/PD model of tacrolimus for exploring the relationship between accumulated exposure and quantitative scores in myasthenia gravis patients

Tacrolimus is an important immunosuppressant used in the treatment of myasthenia gravis (MG). However, the population pharmacokinetic (PK) characteristics together with the exposure-response of tacrolimus in the treatment of MG remain largely unknown. In this study, we aimed to develop a population PK/pharmacodynamic (PK/PD) model of tacrolimus in patients with MG, in order to explore the relationships among tacrolimus dose, exposure, and its therapeutic efficacy. The genotype of CYP3A5, Osserman's classification, and status of thymus, as well as demographic characteristics and other biomarkers from laboratory testing were tested as covariate, and simulations were performed based on the final model. The population PK model was described using a one-compartment model with first-order elimination and fixed absorption parameters. CYP3A5 genotype significantly influenced the apparent clearance, and total protein (TP) influenced the apparent volume of distribution as covariates. The quantitative MG scores were characterized by the cumulated area under curve of tacrolimus in a maximum effect function. Osserman's classification was a significant covariate on the initial score of patients with MG. The simulations demonstrated that tacrolimus showed an unsatisfying effect possibly due to insufficient exposure in some patients with MG. A starting dose of 2 mg/d and even higher dose for patients with CYP3A5 *1/*1 and *1/*3 and lower TP level were required for the rapid action of tacrolimus. The population PK/PD model quantitatively described the relationships among tacrolimus dose, exposure, and therapeutic efficacy in patients with MG, which could provide reference for the optimization of tacrolimus dosing regimen at the individual patient level.

Lymphoplasmapheresis versus plasma exchange in severe myasthenia gravis: a retrospective cohort study

Background

Lymphoplasmapheresis (LPE) is a new therapy developed on the basis of traditional plasma exchange (PE) in combination with leukapheresis. Currently, it remains unclear whether PE and LPE show differences in efficacy for severe MG.

Methods

A retrospective analysis was conducted on 198 MG patients, 75 in the PE group and 123 in the LPE group, and the patients' Myasthenia Gravis Foundation of America (MGFA) Clinical Classification was Class IV. The treatment outcome was the change in Quantitative Myasthenia Gravis Score (QMGS) from baseline to the end of treatment. Propensity score matching (PSM) was applied for the balance of confounders between the two groups.

Results

In this study cohort, the safety profile of LPE and PE was good and no serious adverse events were observed. Based on PSM, 62 patients treated with LPE and 62 patients treated with PE were entered into a comparative efficacy analysis. In the PE group, patients underwent a total of 232 replacements, with a mean of 3.74. PE significantly improved the patients' QMGS performance, with the mean QMGS decreasing from 22.98 ± 4.03 points at baseline to 18.34 ± 5.03 points after treatment, a decrease of 4.68 ± 4.04 points (p < 0.001). A decrease of ≥3 points in QMGS was considered a significant improvement, with a treatment response rate of 67.7% in the PE group. In the LPE group, patients received a total of 117 replacements, with a mean of 1.89. The patients' mean QMGS was 23.19 ± 4.11 points at baseline and was 16.94 ± 5.78 points after treatment, a decrease of 6.26 ± 4.39 points (p < 0.001). The improvement in QMGS was more significant in patients treated with LPE compared to the PE group (p = 0.039). The treatment response rate in the LPE group was 79%, which was not significantly different compared to the PE group (p = 0.16). The LEP group had a shorter mean length of stay compared to the PE group (10.86 ± 3.96 vs. 12.14 ± 4.14 days), but the difference was not statistically significant (p = 0.13). During the 2-month follow-up period, LPE may be associated with better functional outcomes for patients, with lower QMG score and relapse rate. LPE and PE were both effective in reducing the levels of inflammatory cytokines (TNF-α, IL-1β, and IL-6) and AChR-Ab. Compared to PE, LPE was superior in the reduction of AChR-Ab titer.

Conclusion

In severe MG, LPE may be a more preferred treatment option than PE. It achieves treatment outcomes that are not inferior to or even better than PE with fewer replacements. This study provides further evidence to support the application of LPE as a new treatment option for MG.

Time to achieve a patient acceptable symptom state in myasthenia gravis

Introduction

The patient acceptable symptom state (PASS) is a reliable way to characterize a patient's satisfaction with their disease state in a "Yes"/"No" dichotomous manner. There is limited data on the time required to reach an acceptable state in Myasthenia Gravis (MG). We aimed to determine the time to reach a first PASS "Yes" response in patients at MG diagnosis and a PASS "No" status, and also to determine the influence of various factors on this time.

Methods

We performed a retrospective study of patients diagnosed with myasthenia gravis who had an initial PASS "No" response and defined the time to reach a first PASS "Yes" by Kaplan-Meier analysis. Correlations were made between demographics, clinical characteristics, treatment and disease severity, using the Myasthenia Gravis Impairment Index (MGII) and Simple Single Question (SSQ).

Results

In 86 patients meeting inclusion criteria, the median time to PASS "Yes" was 15  months (95% CI 11-18). Of 67 MG patients who achieved PASS "Yes," 61 (91%), achieved it by 25  months after diagnosis. Patients who required only prednisone therapy achieved PASS "Yes" in a shorter time with a median of 5.5  months (p = 0.01). Very-late-onset MG patients reached PASS "Yes" status in a shorter time (HR = 1.99, 95% CI 0.26-2.63; p = 0.001).

Discussion

Most patients reached PASS "Yes" by 25  months after diagnosis. MG patients who only required prednisone and those with very-late-onset MG reach PASS "Yes" in shorter intervals.

Global research hotspots and frontiers of myasthenia gravis from 2002 to 2021: A bibliometric study

The objective of this study is to utilize bibliometric and visual analysis techniques to identify hotspots and frontiers of research in myasthenia gravis (MG) and provide valuable references for future research. The Web of Science Core Collection (WoSCC) database was used to retrieve literature data related to MG research, which was then analyzed using VOSviewer 1.6.18, CiteSpace 6.1.R3, and the Online Platform for Bibliometric Analysis. The analysis revealed 6734 publications distributed across 1612 journals and contributed by as many as 24,024 authors affiliated with 4708 institutions across 107 countries/regions. The number of annual publications and citations for MG research has steadily increased over the past 2 decades, with the last 2 years alone witnessing a remarkable increase in annual publications and citations to over 600 and 17,000, respectively. In terms of productivity, the United States emerged as the top producing country, while the University of Oxford ranked first in terms of research institutions. Vincent A was identified as the top contributor in terms of publications and citations. Muscle & Nerve and Neurology ranked first in publications and citations respectively, with clinical neurology and neurosciences among the main subject categories explored. The study also identified pathogenesis, eculizumab, thymic epithelial cells, immune checkpoint inhibitors, thymectomy, MuSK antibodies, risk, diagnosis, and management as the current hot research topics in MG, while burst keywords like quality of life, immune-related adverse events (irAEs), rituximab, safety, nivolumab, cancer, and classification indicated the frontiers of MG research. This study effectively identifies the hotspots and frontiers of MG research, and offers valuable references for researchers interested in this area.

Myasthenia gravis. Update on diagnosis and therapy

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

Neuromuscular Disorders Associated With COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has had an enormous impact on practically every aspect of daily life, and those with neuromuscular disorders have certainly not been spared. The effects of COVID-19 infection are far-reaching, going well beyond respiratory symptoms alone. From simple myalgias to debilitating critical illness neuromyopathies, we continue to learn and catalog the diverse pathologies presented by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as it relates to the neuromuscular system. Complications have been documented both as a direct result of primary infection but also in those with pre-existing neuromuscular disorders from myasthenia gravis to devastating critical illness neuromyopathies. In this review, we will discuss the relationship between COVID-19 infection and critical illness neuromyopathy, peripheral nerve palsies, myalgias, positional compressive neuropathy, myasthenia gravis, and Guillain-Barré syndrome.

Development and validation of the scale for symptom clusters in patients with myasthenia gravis

BACKGROUND

Patients with myasthenia gravis(MG)often experience multiple symptoms concurrently, which can have an adverse effect on their quality of life(QOL). However, a specific, systemic and reliable scale for symptom clusters in MG is lacking.

AIMS

To develop reliable assessment scale for symptom clusters in patients with MG.

DESIGN

A cross-sectional descriptive study.

METHODS

Based on the unpleasant symptom theory(TOUS), the first draft of the scale was developed through review literature, qualitative interview, and Delphi expert correspondence, the items of the scale were presented and adjusted through cognitive interviews with 12 patients. To conveniently assess the validity and reliability of the scale, a cross-sectional survey was conducted in 283 patients with MG who were recruited from Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, from June to September 2021.

RESULTS

The final symptom cluster scale for patients with MG consisted of 19 items(MGSC-19), with a content validity index ranging from 0.828 to 1.000 for each item and the content validity index was 0.980. Four common variables (ocular muscle weakness, general muscular weakness, treatment-related side effects, and psychiatric problems) were identified by exploratory factor analysis, which explained 70.187% of the total variance. The correlation coefficients between the scale dimension and the overall score ranged from 0.395 to 0.769 (all P < 0.01), while the correlation coefficients between dimensions varied from 0.324 to 0.510 (all P < 0.01). The Cronbach's alpha, retest reliability, and half reliability were 0.932, 0.845, and 0.837, respectively.

CONCLUSION

The validity and reliability of MGSC-19 were generally good. This scale can be employed to identify the symptom clusters to help healthcare givers develop individualized symptom management measures for patients with MG.

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.

An observational study on the safety of COVID-19 vaccination in patients with myasthenia gravis

OBJECTIVE

There is concern that the coronavirus disease (COVID-19) vaccine may trigger or worsen autoimmune diseases. The objective of this study was to determine the impacts of COVID-19 vaccination on symptom severity in patients with myasthenia gravis (MG).

METHODS

A total of 106 enrolled patients with MG who were vaccinated against COVID-19 were followed up, and a questionnaire was used to document in detail the exacerbation of muscle weakness after vaccination and all other uncomfortable reactions after vaccination. Demographic, clinical characteristics, medication, and vaccination data were collected by follow-up interview. The main observation outcome was whether the MG symptoms of patients were exacerbated. The definition of exacerbation is according to the subjective feeling of the patient or a 2-point increase in daily life myasthenia gravis activity score relative to before vaccination, within 30 days after vaccination.

RESULTS

Of 106 enrolled patients [median age (SD) 41.0 years, 38 (35.8%) men, 53 (50.0%) with generalized MG, 74 (69.8%) positive for acetylcholine receptor antibody, and 21 (19.8%) with accompanying thymoma], muscle weakness symptoms were stable in 102 (96.2%) patients before vaccine inoculation. Muscle weakness worsened in 10 (9.4%) people after vaccination, of which 8 patients reported slight symptom worsening that resolved quickly (within a few days). Two (1.9%) of patients showed serious symptom aggravation that required hospitalization.

CONCLUSION

Our results suggest that inactivated virus vaccines against COVID-19 may be safe for patients with MG whose condition is stable. Patients with generalized MG may be more likely to develop increased muscle weakness after vaccination.

Dynamic nomogram for predicting generalized conversion in adult-onset ocular myasthenia gravis

PURPOSE

To explore the factors and risk mapping model of progression from ocular myasthenia gravis (OMG) to generalized myasthenia gravis (GMG) in adult-onset patients.

METHODS

A retrospective, observational cohort study was performed for 435 OMG patients with onset age older than 14 years old. Multivariate Cox regression was used to identify the independent factors affecting generalized conversions that then were incorporated into the construction of the nomogram.

RESULTS

Two hundred thirty-seven patients (54.5%) had transformed into GMG after a median of 1.1 years (range 0.1--9.1 years). The 6-, 12-, and 24-month generalized conversion rates were 31.7%, 49.8%, and 65.4%, respectively. Multivariable analysis showed that the early-onset age, male sex, concomitant autoimmune diseases (AID), positive results of anti-acetylcholine receptor antibodies, repetitive nerve stimulation abnormalities, the presence of thymoma, and prednisone treatment were significantly associated with the generalized conversions (hazard ratio [HR] = 0.598, 0.686, 1.554, 1.541, 2.020, 2.510, and 0.556, respectively). A nomogram was established to predict the possibility of generalization-free survival (GFS) in adult-onset OMG patients, and the model demonstrated good predictive performance with a C-index of 0.736 (95% confidence interval 0.703 ~ 0.769). Moreover, subgroup analyses were performed based on the presence or absence of prednisone therapy, and the results indicated that prednisone therapy has better prevention of generalized conversions in male, non-thymoma patients, and patients without other AID.

CONCLUSION

A new predictive nomograph and web-based survival calculator we developed show favorable applicability and accuracy in predicting long-term GFS in adult-onset OMG patients.

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

Dysregulated immune system with a failure to recognize self from non-self-antigens is one of the common pathogeneses seen in autoimmune diseases. The complex interplay of genetic and environmental factors is important for the occurrence and development of the disease. Among the environmental factors, disturbed gut microbiota (gut dysbiosis) has recently attracted particular attention, especially with advancement in human microbiome research. Although the alterations in microbiota have been seen in various autoimmune diseases, including those of nervous system, there is paucity of information on neuromuscular system diseases. Myasthenia gravis (MG) is one such rare autoimmune disease of neuromuscular junction, and is caused by generation of pathogenic autoantibodies to components of the postsynaptic muscle endplate. In the recent years, accumulating evidences have endorsed the key role of host microbiota, particularly those of gut, in the pathogenesis of MG. Differential microbiota composition, characterized by increased abundance of Fusobacteria, Bacteroidetes, and Proteobacteria, and decreased abundance of Actinobacteria and Firmicutes, has been seen in MG patients in comparison to healthy subjects. Disturbance of microbiota composition, particularly reduced ratio of Firmicutes/Bacteroidetes, alter the gut permeability, subsequently triggering the immunological response. Resultant reduction in levels of short chain fatty acids (SCFAs) is another factor contributing to the immunological response in MG patients. Modulation of gut microbiota via intervention of probiotics, prebiotics, synbiotics, postbiotics (metabiotics), and fecal microbiota transplantation (FMT) is considered to be the futuristic approach for the management of MG. This review summarizes the role of gut microbiota and their metabolites (postbiotics) in the progression of MG. Also, various bacteriotherapeutic approaches involving gut microbiota are discussed for the prevention of MG progression.

Immunological and Structural Characterization of Titin Main Immunogenic Region; I110 Domain Is the Target of Titin Antibodies in Myasthenia Gravis

Myasthenia gravis (MG) is an autoimmune disease caused by antibodies targeting the neuromuscular junction (NJ) of skeletal muscles. The major MG autoantigen is nicotinic acetylcholine receptor. Other autoantigens at the NJ include MuSK, LRP4 and agrin. Autoantibodies to the intra-sarcomeric striated muscle-specific gigantic protein titin, although not directed to the NJ, are invaluable biomarkers for thymoma and MG disease severity. Thymus and thymoma are critical in MG mechanisms and management. Titin autoantibodies bind to a 30 KDa titin segment, the main immunogenic region (MIR), consisting of an Ig-FnIII-FnIII 3-domain tandem, termed I109-I111. In this work, we further resolved the localization of titin epitope(s) to facilitate the development of more specific anti-titin diagnostics. For this, we expressed protein samples corresponding to 8 MIR and non-MIR titin fragments and tested 77 anti-titin sera for antibody binding using ELISA, competition experiments and Western blots. All anti-MIR antibodies were bound exclusively to the central MIR domain, I110, and to its containing titin segments. Most antibodies were bound also to SDS-denatured I110 on Western blots, suggesting that their epitope(s) are non-conformational. No significant difference was observed between thymoma and non-thymoma patients or between early- and late-onset MG. In addition, atomic 3D-structures of the MIR and its subcomponents were elucidated using X-ray crystallography. These immunological and structural data will allow further studies into the atomic determinants underlying titin-based autoimmunity, improved diagnostics and how to eventually treat titin autoimmunity associated co-morbidities.

Comparative the efficacy and acceptability of immunosuppressive agents for myasthenia gravis: A protocol for systematic review and network meta-analysis

BACKGROUND

Immunosuppressive drugs are routinely used to treat myasthenia gravis (MG). However, current recommendations provide limited evidence to support treatment options, leading to considerable variation in practice among healthcare specialists. Hence, we present a protocol for a systematic review and network meta-analysis (NMA) to update the evidence by comparing the efficacy and acceptability of oral immunosuppressive drugs for the treatment of MG.

METHODS

We will conduct a systematic review and NMA of all randomized controlled trials evaluating the following oral immunosuppressive drugs for the treatment of MG. Published studies will be searched using the following databases from inception to November 23, 2021: CENTRAL, the CINAHL, MEDLINE, Embase, PsycINFO, Web of Science, and 3 Chinese databases (Chinese Biomedical Literatures Database, CNKI, and Wan Fang database). Assessment of study eligibility and data extraction will be conducted independently by 2 reviewers. The main outcome will be a quantitative MG scoring system. We will conduct Bayesian NMA to synthesize all evidence for each outcome and obtain a comprehensive ranking of all treatments. The quality of the evidence will be evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations framework.

RESULTS

The objective of this study was to assess the relative clinical efficacy and acceptability of first-line immunosuppressants for the treatment of MG, using a systematic review and NMA approach.

CONCLUSION

In the absence of head-to-head trials comparing therapies, evidence from this NMA of available clinical trials will inform clinicians, patients, and families the risk-benefit profiles of different treatment options.

Pneumonia in myasthenia gravis: Microbial etiology and clinical management

Introduction

Patients with myasthenia gravis (MG) are prone to the development of pneumonia due to the long-term immunotherapies they receive and a tendency for aspiration. Pneumonia remains a risk factor for MG worsening and is the most prevalent cause of mortality in MG patients. Classification of the pathogens involved and exploration of the risk factors for mechanical ventilation (MV) could aid in improving clinical outcomes.

Methods

Between January 2013 and October 2022, we performed an inpatient database review for MG patients with pneumonia concurrence in a tertiary research center specializing in neuromuscular disorders. The clinical and microbiological characteristics of 116 MG patients with pneumonia were retrospectively analyzed.

Results

In our cohort, 90.32% (112/124) of organisms were bacteria and 42.86% (48/112) of pathogenic bacteria were carbapenem-resistant. A high abundance of Epstein-Barr virus (EBV) was detected using next-generation sequencing (NGS) in 12 patients, while cytomegalovirus (CMV) was detected in 8 patients. Non-fermentative Gram-negative bacilli were the most prevalent microorganisms, in which ampicillin, sulfamethoxazole-trimethoprim (SMZ-TMP), piperacillin, cefoperazone, ceftazidime, and cefepime may have an anti-infectious effect. Moreover, peripheral lymphocyte percentage [odds ratio (OR) 0.88, 95% CI 0.75-0.96, p = 0.02] and serum globulin (OR 1.16, 95% CI 1.02-1.35, p = 0.03) were significantly associated with the risk of MV demand.

Discussion

Our identification of the microbial etiology of pneumonia in MG patients may provide future perspectives on accurate antibiotic options and enable early interventions when risk factors are present.

The relationship between myasthenia gravis and COVID-19: a systematic review

Introduction

Viral infection such as coronavirus disease 2019 (COVID-19) can exacerbate and aggravate neurological disorders due to autoimmune etiology like myasthenia gravis (MG). Experimental therapies used in COVID-19 are also factors that can cause the worsening of MG symptoms. This review aimed to assess and conclude the research-based study systematically to analyze the relationship of MG and COVID-19.

Method

This study was conducted in accordance to Cochrane handbook for systematic reviews and the guideline of preferred reporting items for systematic review and meta-analysis (PRISMA) and synthesis without meta-analysis (SWiM) in systematic reviews: reporting guideline. Inclusion criteria in this review were primary studies of every design, articles published in English around January 2000–October 2021, and the study used human as subject. A systematic literature finding was applied in 15 electronic scientific resources. The authors evaluated the study quality and risk of bias of each retrieved article.

Results

The authors found the study through electronic scientific resources that met inclusion and exclusion criteria. The authors evaluated 362 articles identified in literature searching, 22 articles met the criteria for this review and then underwent the evaluation of study quality and risk of bias.

Conclusion

COVID-19 infection can increase the risk of new-onset MG, myasthenic crisis, respiratory failure, and mortality rate due to cytokine storm in MG patients. The management of COVID-19 patients with MG is tailored to each person and based on national guidelines and local expert recommendations.

Increased Expression of CD95 in CD4+ Effector Memory T Cells Promotes Th17 Response in Patients with Myasthenia Gravis

Emerging data have revealed that CD95 can evoke non-apoptotic signals, thereby promoting pro-inflammatory functions that link to the severity of autoimmune disorders. Here, we reported that the expression of CD95 in CD4⁺ effector memory T (CD4⁺ TEM) cells was increased in myasthenia gravis (MG) patients. We also found increased expression of CD95 in CD4⁺ TEM cells from MG patients correlated positively with clinical severity scores (QMGs), serum IL-17 levels and plasma cells (PCs) frequencies. Conventional treatment, such as glucocorticoid, could down-regulate the expression of CD95 in CD4⁺ TEM cells, QMGs, serum IL-17 levels and PCs frequencies from MG patients. In vitro, low-dose of agonistic anti-CD95 mAb could promote Th17 cell development. This effect was reversed by CD95 siRNA. Moverover, CD95 stimulation induced the phosphorylation of p38 and Erk1/2 and Th17 cell differentiation, and p38 specific inhibitor SB203580 or Erk1/2 specific inhibitor PD98059 could induce opposite changes. However, SB203580 or PD98059 do not abrogate the increase of CCR6⁺IL-17A⁺ cells, ROR-γt and IL-17 expression induced by CD95 triggering relatively to each corresponding control. This suggests that p38 and Erk1/2 MAPK pathway plays a role in expression of CCR6⁺IL-17A⁺ cells, ROR-γt and IL-17, but not in their increase induced by CD95 triggering. Taken together, this study revealed that increased expression of CD95 in CD4⁺ TEM cells promotes Th17 response under the microenvironment of MG.