Quality of life in patients with MuSK positive myasthenia gravis

MuSK Myasthenia Gravis-Potential Pathomechanisms and Treatment Directed against Specific Targets

Myasthenia gravis (MG) is an autoimmune disease in which autoantibodies target structures within the neuromuscular junction, affecting neuromuscular transmission. Muscle-specific tyrosine kinase receptor-associated MG (MuSK-MG) is a rare, often more severe, subtype of the disease with different pathogenesis and specific clinical features. It is characterized by a more severe clinical course, more frequent complications, and often inadequate response to treatment. Here, we review the current state of knowledge about potential pathomechanisms of the MuSK-MG and their therapeutic implications as well as ongoing research in this field, with reference to key points of immune-mediated processes involved in the background of myasthenia gravis.

Systematic review of the patient burden of generalised myasthenia gravis in Europe, the Middle East, and Africa

BACKGROUND

Myasthenia gravis (MG) is a rare autoimmune disease characterised by muscle weakness, and progression from ocular (oMG) to generalised (gMG) symptoms results in a substantial negative impact on quality of life (QoL). This systematic review aimed to provide an overview of the patient burden experienced by people living with gMG.

METHODS

Electronic database searches (conducted March 2022), supplemented by interrogation of grey literature, were conducted to identify studies reporting patient burden outcomes in patients with gMG in Europe, the Middle East and Africa. Results were synthesised narratively due to the heterogeneity across trials.

RESULTS

In total, 39 patient burden publications (representing 38 unique studies) were identified as relevant for inclusion in the systematic review, consisting of 37 publications reporting formal patient-reported outcome measures (PROMs), and two publications describing alternative qualitative assessments of patient experience. The studies included a variety of measures including generic and disease-specific PROMs, as well as symptom-specific PROMs focusing on key comorbidities including depression, anxiety, fatigue and sleep disturbance. The findings showed some variation across studies and PROMs; however, in general there was evidence for worse QoL in patients with gMG than in healthy controls or in patients with oMG, and a trend for worsening QoL with increasing MG severity.

CONCLUSIONS

This review highlights the importance of considering patient QoL when developing and assessing treatment and management plans for patients with gMG. However, the heterogeneity identified across studies illustrates the need for further representative and well-powered studies in large cohorts administering consistent, validated questionnaires.

TRIAL REGISTRATION

The protocol for this systematic review was registered in PROSPERO: CRD42022328444.

Health-related quality of life (HRQoL) and psychological impact of the COVID-19 pandemic on patients with myasthenia gravis

The aim of this study was to compare the effects of the pandemic on health-related quality of life (HRQoL), anxious-depressive symptoms, feelings of loneliness, and fear of COVID-19 between people with myasthenia gravis (MG) and healthy controls. We also wanted to know in which group the variable fear of COVID-19 interfered the most with the results. This cross-sectional study involved 60 people with MG and 60 healthy controls. Participants using an online platform completed a sociodemographic questionnaire, the Short Form-36 Health Survey (SF-36), the Hospital Anxiety and Depression Scale (HADS), the revised UCLA Loneliness Scale and the Fear of COVID19 Scale (FCV- 19S). The MG group reported worse levels in HRQoL indicators (p = 0.043- <.001), more severe anxiety-depressive symptoms (p = 0.002), and greater fear of COVID-19 (p < 0.001), but there were no differences in feelings of loneliness (p = 0.002). Furthermore, after controlling for the effect of the fear of COVID-19 variable, the differences remained for physical health indicators, but not for the most of psychosocial indicators (Social Functioning p = 0.102, η²_p = 0.023; Role Emotional p = 0.250, η²_p = 0.011; and HADS Total p = 0.161, η²_p = 0.017). The harmful effect of the COVID-19 pandemic was greater in the MG group, and the perceived fear of COVID-19 had also a greater impact among this group, which has increased its negative effect on their psychosocial health.

COVID-19 infection and vaccination against SARS-CoV-2 in myasthenia gravis

INTRODUCTION

Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction which is typically presented with muscle weakness and excessive fatigability. Majority of MG patients require long-term immune suppression. Our aim was to analyze the frequency and severity of COVID-19 infection in MG patients, as well as the frequency of vaccinated MG patients against SARS-CoV-2.

METHODS

We included 125 MG patients from the central Belgrade municipalities-60% females, age at MG onset 50.1 ± 19.7 years, age at testing 61.7 ± 16.8 years, anti-acetylcholine receptor (anti-AChR) positive 78% and muscle specific tyrosine kinase (MuSK) positive 8.6%.

RESULTS

One-third of our MG patients had a COVID-19 infection and they were younger compared to those without verified COVID-19. Severe COVID-19 infection was registered in 28% of MG patients, mostly in elder subjects with comorbidities such as cardiac diseases and malignancies. MG worsening was noted in 21% of patients during/after COVID-19 and 42% had COVID-19 sequelae. Majority of MG patients were vaccinated against SARS-CoV-2 (almost 70%). Vaccination was more common among MG patients with diabetes and in those with a milder form of MG. The most common types of vaccines were Sinopharm (42%) and Pfizer-BioNTech (25.6%). Adverse events were observed in 36% of vaccinated patients, with flu-like symptoms (77%) and local reactions (13%) being the most common ones. MG worsening was noticed in 5 (5.8%) patients after vaccination.

CONCLUSION

COVID-19 has placed a significant new burden for MG patients. Elder MG patients and patients with comorbidities are in higher risk of having adverse outcome following SARS-CoV-2 infection. Percentage of vaccinated MG patients was higher than in general Serbian population.

Anti-titin antibody is associated with more frequent hospitalization to manage thymoma-associated myasthenia gravis

BACKGROUND AND PURPOSE

Anti-titin antibodies are antistriational antibodies associated with thymoma-associated myasthenia gravis (MG). We evaluated whether the patients with anti-titin antibody are more frequently hospitalized to manage thymoma-associated MG than those patients without anti-titin antibody.

METHODS

Patients with thymoma-associated MG who conducted the serological test for anti-titin antibody were retrospectively included. Disease severity, treatments, MG-related annual hospitalization rate, and MG-related emergency room (ER) visit rate were compared between the patients with anti-titin antibody and those patients without anti-titin antibody. Multivariate analysis was conducted to analyze the association between anti-titin antibody serostatus and multiple admissions (hospitalization or ER visit of ≥2 times).

RESULTS

Of the 64 included patients, 31 (48.4%) patients were positive for anti-titin antibody (titin+ group) and 33 (51.6%) patients were negative for anti-titin antibody (titin- group). Both the annual rate of MG-related hospitalization and ER visit were significantly higher in the titin+ group [0.2 (0.1-0.6) and 0.1 (0-0.2) per year, respectively] than those in the titin- group [0 (0-0.2) and 0 (0-0) per year, p = 0.004 and p = 0.006, respectively]. In multivariate analysis, positive anti-titin antibody was still significantly associated with multiple admissions [odds ratio (OR) 4.11, 95% CI 1.05-16.03] compared to the titin- group as a reference after adjusting for sex, follow-up duration, age at onset, systemic chemotherapy, and the Masaoka staging.

CONCLUSION

The presence of anti-titin antibody is associated with more frequent hospital utilization. Personalized explanation and careful monitoring strategy could be required in patients with thymoma-associated MG with anti-titin antibody for the timely detection of relapses.

A novel MuSK cell-based myasthenia gravis diagnostic assay

To improve the clinical diagnosis of neural autoimmune diseases, we developed an in-house muscle-specific kinase (MuSK) antibody cell-based assay (CBA) and compared its performance with RIA, ELISA, and other CBAs. Sera from patients with myasthenia gravis (MG) and other autoimmune diseases were analyzed. We found 46 (18.3%) MuSK-CBA Ab positive cases among 251 AChR-Ab negative cases [patients] and 4 (0.6%) MuSK-CBA Ab positive cases [among] the 624 AChR-Ab positive samples. Comparing these with available clinic assays, our highly specific CBA method is more sensitive than commercial ELISA and IFA(indirect immunofluorescence assay).

Severity and depression can impact quality of life in patients with myasthenia gravis

BACKGROUND

The revised 15-item Myasthenia Gravis (MG) Quality of Life Questionnaire (MGQoL15R) is a validated scale of quality of life in patients with MG. We aimed to study the factors causing the variability within the Arabic version of the MGQoL15R (MGQoL15R-A).

METHOD

A standardized questionnaire was completed by 118 patients. Correlations and hierarchical regression analyses were used to assess the contribution of sociodemographic variables, clinical factors, Patient Health Questionnaire-9 (PHQ9-A), and Generalized Anxiety Disorder-7 (GAD7-A) to the variability in the MGQoL15R-A.

RESULTS

The MGQoL15R-A was highly correlated with PHQ9-A (r = 0.76), and moderately correlated with GAD7-A (r = 0.52). Clinical factors and PHQ9-A independently explained 30.4% and 34.5% of the variability, respectively. Among the clinical factors, uncontrolled MG status, relapse within the past year, and a higher number of current MG therapies were significantly associated with a higher MGQoL15R-A score.

CONCLUSIONS

MG severity and depressive symptoms (measured by PHQ9-A) can affect the MGQoL15R-A score.

Factors associated with quality of life of people with Myasthenia Gravis

Purpose

As most of patients with Myasthenia Gravis have limitations in their physical functioning, many experience changes in psychological states and often have depression. The objective of the current study was to examine the roles of communication with medical professionals, patients’ loneliness, and patients’ depression, in relation to their effects on the patients’ quality of life.

Methods

For 120 patients with MG of 18 years and older, demographic variables, along with communication with medical professionals, loneliness, depression, and quality of life were measured.

Results

As a result, people suffering from MG experienced lower quality of life when their career has changed due to the illness. At the same time, depression was a significant predictor of their quality of life, both in physical and mental domains.

Conclusions

The implications for clinical settings and the suggestions for future research are discussed.