Comorbidities worsen the prognosis of generalized myasthenia gravis post-thymectomy

Intensive care due to myasthenia gravis: Risk factors and prognosis

BACKGROUND AND PURPOSE

Exacerbation of myasthenia gravis (MG) with respiratory failure requires intensive care. We aimed to study the risk factors for intensive care unit admission for MG exacerbation and myasthenic crisis (MC) and the prognosis of people with MG (pwMG) thereafter.

METHODS

This retrospective study investigated patients in the Helsinki and Uusimaa hospital district during the years 2008-2021. PwMG (International Classification of Diseases, 10th revision code G70.0) were identified through a data repository search, followed by a chart review of patient records. Risk factors for intensive care due to MG exacerbation were evaluated as compared with the patients only treated in the outpatient clinic and those treated in the neurological ward for MG exacerbation. The outcomes of patients in intensive care for any reason were also compared with those of patients in intensive care for exacerbation of bronchial asthma.

RESULTS

Of 577 pwMG, 35 (6.1%) needed intensive care for MG within a median of 5.3 months from diagnosis. The mean (±SD) age at MG diagnosis was higher in the intensive care group (60.5 [±16.1] years) compared to the outpatient (48.3 [±20.9] years; p < 0.001) and neurological ward groups (53.4 [±20.8] years; p = 0.044). Thymoma (odds ratio [OR] 4.8, 95% confidence interval [CI] 1.19-19.43; p = 0.028) and female sex (OR 2.1, 95% CI 1.02-4.48; p = 0.045) were independent risk factors for intensive care. In-hospital mortality was 4% for MC patients. Six-month mortality after intensive care for MG exacerbation (14.3%) was twice that for asthma exacerbation (7.7%).

CONCLUSION

Our study shows an increased risk of intensive care treatment for patients with late-onset MG, female sex or thymoma, occurring usually within 6 months from diagnosis, which emphasises the importance of early treatment choices.

Clinical characteristics and impairment of activities of daily living among patients with myasthenia gravis with differing degrees of muscle weakness: a real-world study of patients in the US and five European countries

BACKGROUND

Real-world data were employed to determine clinical characteristics of patients with myasthenia gravis (MG) with differing degrees of muscle weakness, as defined using the Myasthenia Gravis Foundation of America (MGFA) classification system.

METHODS

Data were drawn from the Adelphi MG Disease Specific Programme (DSP)™, a multinational (United States, France, Germany, Italy, Spain, United Kingdom) survey completed by physicians and their patients with MG in 2020. The association between MGFA class and impairment in activities of daily living (ADL) was tested using linear regression adjusting for sex and Charlson Comorbidity Index. Bivariate comparisons were performed for each individual item. A range of other clinical characteristics were also explored according to MGFA class.

RESULTS

Among 1232 patients, those in MGFA class I had significantly lower ADL impairment versus class II or III/IV (adjusted for sex and Charlson Comorbidity Index) (p < 0.01). However, heterogeneity occurred within each MGFA class. Bulbar symptoms (impaired speech, difficulty swallowing, and/or difficulty chewing/choking on food) were reported in some class I patients (mild in 1.1-1.9% and moderate in 0.3-1.1% of patients) and class II patients (mild in 8.5-16.4%, moderate in 4.7-7.4%, and severe in 0.3-0.9% of patients), and shortness of breath was reported in some class I (mild in 0.5% of patients) and class II patients (mild in 9.8%, moderate in 4.8%, and severe in 0.3% of patients). Conversely, in 11.2-19.2% of class III/IV patients, bulbar symptoms and shortness of breath reported were only mild in severity. In line with this finding, despite significant correlations between MGFA class and several clinical characteristics, patients across every class were at risk of experiencing myasthenic crisis or hospitalization, experiencing comorbidities including anxiety and depression, and not being in remission.

CONCLUSIONS

Although MGFA class correlates with greater ADL impairment and presence of other clinical characteristics, there is variability between patients in each class in terms of symptoms experienced, overall disease burden, and the precise nature of ADL impairment.

Epidemiology of myasthenia gravis in Denmark, Finland and Sweden: a population-based observational study

BACKGROUND

Incidence and prevalence rates of myasthenia gravis (MG) vary considerably across studies, and mortality risk is rarely addressed. We examined the prevalence and incidence rates, mortality and factors associated with mortality with MG.

METHOD

This was a registry linkage study based on nationwide health and administrative registries of Denmark, Finland and Sweden (populations of 5.9, 5.6 and 10.5 million, respectively). Patients with MG were identified based on International Classification of Diseases codes from inpatient and outpatient specialised care registries. Yearly prevalence, incidence and mortality rates in relation to the total background population were calculated from 2000 to 2020 (study period). The causes of death and factors associated with mortality were addressed separately.

RESULTS

The overall incidence of MG was 1.34 (95% CI 1.27 to 1.41), 1.68 (95% CI 1.60 to 1.75) and 1.62 (95% CI 1.56 to 1.68) per 100 000, and the overall prevalence per 100 000 was 18.56 (95% CI 18.31 to 18.81), 20.89 (95% CI 20.62 to 21.16) and 23.42 (95% CI 23.21 to 23.64) in Denmark, Finland and Sweden, respectively. The overall standardised mortality ratio (SMR) was 1.32 (95% CI 1.23 to 1.42) among patients with MG in Denmark, 1.23 (95% CI 1.15 to 1.33) in Finland, and 1.20 (95% CI 1.14 to 1.26) in Sweden, with higher SMR observed in women than men. Annual incidence and prevalence increased over time, whereas the SMR remained stable. The most common causes of death were MG, chronic ischaemic heart disease and acute myocardial infarction.

CONCLUSIONS

This population-based study from three Nordic countries highlights the need for improved care of patients with MG, especially young women.

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

INTRODUCTION

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Recommendations for the management of myasthenia gravis in Belgium

International guidelines on the treatment of myasthenia gravis (MG) have been published but are not tailored to the Belgian situation. This publication presents recommendations from a group of Belgian MG experts for the practical management of MG in Belgium. It includes recommendations for treatment of adult patients with generalized myasthenia gravis (gMG) or ocular myasthenia gravis (oMG). Depending on the MG-related antibody a treatment sequence is suggested with therapies that can be added on if the treatment goal is not achieved. Selection of treatments was based on the level of evidence of efficacy, registration and reimbursement status in Belgium, common daily practice and the personal views and experiences of the authors. The paper reflects the situation in February 2024. In addition to the treatment considerations, other relevant aspects in the management of MG are addressed, including comorbidities, drugs aggravating disease symptoms, pregnancy, and vaccination. As many new treatments might potentially come to market, a realistic future perspective on the impact of these treatments on clinical practice is given. In conclusion, these recommendations intend to be a guide for neurologists treating patients with MG in Belgium.

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.

Comorbidity in myasthenia gravis: multicentric, hospital-based, and controlled study of 178 Italian patients

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disorder with fluctuating weakness that causes significant disability and morbidity. Comorbidities may influence the course of MG, particularly in specific subgroups. The aim of this study is to investigate the frequency of comorbidities in MG patients compared to healthy controls (HC) and to evaluate their distribution according to age at disease onset, sex, and disease severity.

METHODS

MG patients attending the University Hospital "Paolo Giaccone" in Palermo and "SS Annunziata" Hospital in Chieti were enrolled; HC were enrolled from the general population. Non-parametric statistics and logistic regression were used to assess the association of specific comorbidities according to age at disease onset, sex, disease subtypes, and severity of the disease.

RESULTS

A total of 356 subjects were included in the study: 178 MG patients (46% F; median age 60 years [51-71]) and 178 sex- and age-matched HC (46% F, median age 59 years [50-66]). Overall, 86% of MG patients and 76% of HC suffered from comorbidities, and MG patients had a higher number of comorbidities compared to HC. Patients with late-onset suffered from more comorbidities than those with early-onset MG. Hypertension was more common in male patients with MG, while thymic hyperplasia, osteoporosis, and autoimmune diseases were more common in females. Respiratory disorders and thymoma were more common in patients with more severe disease (p < 0.05 for all comparisons).

CONCLUSION

MG patients, particularly those with late onset, showed a higher prevalence of comorbidities than HC. Assessment of comorbidities in MG is an essential issue to identify the appropriate treatment and achieve the best management.

Autoimmune and Non-Autoimmune Comorbidities in Myasthenic Patients of East-European Descent: A Case-Control Study

Background: As the life expectancy of patients with myasthenia gravis (MG) is improving, so the number of comorbidities continues to rise, with a potentially significant impact on the overall morbidity and mortality. The main aim of the study was to assess comorbidities of MG in a group of patients of East-European descent. Methods: We retrospectively compared 185 adult myasthenic patients with 895 sex- and age-matched controls, admitted from January 2013 to December 2021. Results: Of these patients, 60% had late-onset MG (LOMG), with a clear predominance of women in both the LOMG and early-onset (EOMG) types; and 23.8% of the patients had a radiological description consistent with thymoma. All myasthenic patients had at least one comorbidity; 20 (10.8%) of the patients associated at least one autoimmune comorbidity. Obesity (p < 0.01), type 2 diabetes (p < 0.0001), cerebrovascular diseases (p < 0.0001), essential hypertension (p < 0.01), and cardiac arrythmias (p < 0.0001) were more frequent in patients than in the control group. The granulocyte-to-lymphocyte ratio was higher in the myasthenic patients compared to the controls (p < 0.01 for LOMG). Discussion: We, thus, suggest a common chronic low-grade inflammatory background as a possible connection between MG subtypes and some of these apparently unconnected comorbidities. Conclusions: The East-European origin of the patients offered a different social and cultural angle of a disease studied mainly on populations of West-European and Asian descent.

Epidemiology of myasthenia gravis in France: A retrospective claims database study (STAMINA)

BACKGROUND

The objectives of this observational study were to report the incidence and prevalence of myasthenia gravis (MG) in France, describe patients' characteristics and treatment patterns, and estimate mortality.

METHODS

A historical cohort analysis was performed using the French National Health Data System (SNDS) database between 2008 and 2020. Patients with MG were identified based on ICD-10 codes during hospitalization and/or long-term disease (ALD) status, which leads to a 100% reimbursement for healthcare expenses related to MG. The study population was matched to a control group based on age, sex and region of residence.

RESULTS

The overall incidence of MG was estimated at 2.5/100,000 in 2019 and the overall prevalence at 34.2/100,000. The mean age was 58.3 years for incident patients and 58.6 for prevalent patients. Among patients with MG, 57.1% were women. In the first year after identification of MG, acetylcholinesterase inhibitors were the most commonly used treatments (87.0%). Corticosteroids were delivered to 58.3% of patients, intravenous immunoglobulin to 34.4%, and azathioprine to 29.9%. Additionally, 8% of patients underwent thymectomy. The proportions of patients with exacerbations and crises were 59.7% and 13.5% respectively in the first year after MG identification. All-cause mortality was significantly higher in patients with MG compared to matched controls (HR=1.82 (95% CI [1.74;1.90], P<0.0001)).

CONCLUSION

In this study, the incidence and prevalence of MG estimated in France were found to be higher than previously reported. Most exacerbations and crises occurred within the first year after MG identification. MG was associated with increased mortality compared to a control population matched on age, gender, and geographical region.

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

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

Disease-Based Prognostication: Myasthenia Gravis

Myasthenia gravis (MG) is an acquired autoimmune neuromuscular junction transmission disorder that clinically presents as fluctuating or persistent weakness in various skeletal muscle groups. Neuroprognostication in MG begins with some basic observations on the natural history of the disease and known treatment outcomes. Our objective is to provide a framework that can assist a clinician who encounters the MG patient for the first time and attempts to prognosticate probable outcomes in individual patients. In this review article, we explore clinical type, age of onset, antibody status, severity of disease, thymus pathology, autoimmune, and other comorbidities as prognostic factors in MG.

Thymectomy in myasthenia gravis

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Insights from a Case of Good's Syndrome (Immunodeficiency with Thymoma)

Immunodeficiency with thymoma was described by R.A. Good in 1954 and is also named after him. The syndrome is characterized by hypogammaglobulinemia associated with thymoma and recurrent infections, bacterial but also viral, fungal and parasitic. Autoimmune diseases, mainly pure red cell aplasia, other hematological disorders and erosive lichen planus are a common finding. We describe here a typical case exhibiting all these clinical features and report a detailed immunophenotypic assessment, as well as the positivity for autoantibodies against three cytokines (IFN-alpha, IL-6 and GM-CSF), which may add to known immune abnormalities. A review of the published literature, based on case series and immunological studies, offers some hints on the still unsolved issues of this rare condition.

Patient-reported impact of myasthenia gravis in the real world: findings from a digital observational survey-based study (MyRealWorld MG)

OBJECTIVES

This study aims to explore the impact of myasthenia gravis (MG) - in terms of treatments, side effects, comorbidities, psychological health and work or study- in the real world from a patient perspective.

DESIGN AND PARTICIPANTS

This is a prospective, observational, digital, longitudinal study. Adults diagnosed with MG residing in the USA, Japan, Germany, the UK, Italy, Spain or Canada were eligible to participate in the study. There were no other exclusion criteria. Participants used a bespoke smartphone application to confirm eligibility, provide consent and enter data about their MG into a profile, a tracker to record MG-related events and a series of patient-reported outcome instruments. 1693 participants completed at least 1 survey and were included in this analysis.

RESULTS

Results are presented as a percentage of respondents to each survey question. The study population was largely female (69% of 1586 respondents), with an average age of 49.9 years (SD 14.8). In the previous 12 months, 83.7% of 1412 respondents confirmed that they had received one or more routine treatments for MG, and 67.1% of 255 respondents confirmed that they had experienced a side effect in the previous month. Commonly experienced comorbidities reported by 966 respondents were thyroid problems, hypertension and anxiety, experienced by 37.5%, 31.4% and 28.0% of respondents, respectively.According to 889 respondents to the Hospital Anxiety and Depression Scale survey, 52.7% and 43.2% had a score indicative of at least mild anxiety and mild depression, respectively. Of 257 respondents, 33.0% reported experiencing a work or study impact in the past month.

CONCLUSIONS

This analysis of baseline characteristics of the MyRealWorld MG study population indicates that, despite current treatments, patients experience notable burden. Further scheduled analyses will develop a longitudinal picture of MG burden.

TRIAL REGISTRATION NUMBER

NCT04176211.

Effects of comorbid diseases on clinical outcomes in patients with myasthenia gravis

BACKGROUND

This cross-sectional study was undertaken to evaluate the existence and distribution of comorbid disorders among myasthenia gravis (MG) patients according to subgroups and to identify the effects of the comorbid diseases of MG patients on clinical outcomes.

METHODS

The patients were divided into six subgroups according to serum antibodies, age at onset, and thymoma presence. All patients were treated in line with the International Consensus Guidance for Management of Myasthenia Gravis. To assess the clinical outcome after treatment for MG, we used the MGFA Post-intervention Status. In generalized MG patients, the good prognosis group included patients who were classified as having minimal-manifestation status or better. In ocular MG patients, the remission subgroup included patients who were classified as having complete stable remission or pharmacological remission status.

RESULTS

Our study included 168 MG patients, 85 were female while 83 were male. Comorbid diseases were present in 124 (73.8%) MG cases. After at least 1 year of follow-up, 106 (86.8%) of the generalized MG patients were in the good prognosis group and 16 (13.2%) generalized MG patients were in the poor prognosis group. 27 (58.6%) ocular MG patients were in the remission group and 19 (41.3%) ocular MG patients were in the non-remission group. Hypertension increased the risk of poor prognosis by 3.55-fold among patients with generalized MG and type 2 DM increased the risk of not achieving remission by 9.32-fold among patients with ocular MG.

CONCLUSION

Hypertension and type 2 DM had negative effects on the clinical outcomes of MG.

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

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