Clinical characteristics of late-onset myasthenia gravis.

Objective: Late-onset myasthenia gravis (LOMG) often has comorbidities, and its initial symptoms may be ignored or misdiagnosed as other diseases. There were few large surveys on LOMG. Our study aimed to summarize clinical characteristics of LOMG to improve the rate of correct MG diagnosis. Methods: A retrospective cohort study included 240 LOMG patients with onset age ≥65 years old who were treated at PLA General Hospital from January 1, 2003 to January 1, 2023. Results: The male to female ratio was 1:1.2 (P = 0.699). MGFA clinical classification: Class I 31.3%, Class IIa 12.9%, Class IIb 51.3%, Class IIIa 0.8%, Class IIIb 0.8%, Class IV 0.4%, Class V2.5%. The onset symptom was ptosis in 78.8% and diplopia was in 18.8%. Swallowing dysfunction in the stage of LOMG was in 41.7%. The incidence of thymoma in LOMG was 14.2%. 85.4% of patients antibodies against the muscle acetylcholine receptor (AChR) are detected. The overall incidence of supramaximal repetitive nerve stimulation (Jolly test) was 57.1%, among which the highest positive rate (50.7%) was in the facial nerve. Jolly test of Class IIb was tested in the highest positive rate and Class I was in the lowest one (χ2 = 7.023, P = 0.030). Conclusion: There was no significant difference in the incidence of LOMG between males and females. The clinical manifestations were mainly Class I and Class II, and severe MG was rare. The most common onset symptom was ptosis. The incidence of LOMG with thymoma was low. Supramaximal repetitive nerve stimulation (Jolly test) of the facial nerve was the easiest to detect and Jolly test of Class IIb was tested in the highest positive rate and Class I was in the lowest one.

Myasthenia gravis concurrent with Parkinson's disease in a Spanish cohort. Causation or correlation?

BACKGROUND: Comorbidity between myasthenia gravis (MG) and other autoimmune diseases is well-documented. However, concurrent MG and Parkinson's disease (PD) have rarely been described. This concurrence has mostly been considered coincidental in cases reported to date. MATERIAL/METHODS: We characterized patients with concurrent MG and PD within a cohort of 631 MG patients by gender, age, MGFA class, quantitative MG score at diagnosis, UPDRS score at diagnosis, and the DaTSCAN uptake pattern, to determine the frequency and the phenotype of individuals with these two concurrent entities. Meta-analysis of cases in the literature was used for comparison with our series. RESULTS: Eighteen cases were identified in which the two diseases were concurrent. The major characteristics of the phenotype are male prevalence, late-onset MG, and frequent initial symptoms of dropped head and oculobulbar involvement. DAT confirmed reduced bilateral uptake in eleven patients and reduced unilateral uptake in the others. CONCLUSIONS: To our knowledge, this is the largest reported series of concurrent MG and PD. This concurrence is more common than expected (2.85%). Either MG or PD may appear first. We found no iatrogenic relationship for the order of appearance. The overlapping of symptoms sometimes leads physicians to overlook the second disease, instead viewing it as a deterioration of the first. This study describes patients with well-documented diagnoses of both MG and PD, thus providing further indications of a shared etiology of these two diseases. Prospective studies including genetic, immunological, and environmental analysis are necessary to identify possible common pathogenic mechanisms.

A Pilot Study on Tocilizumab in Very-Late-Onset Myasthenia Gravis.

Objective: This study aimed to initially investigate the efficacy and safety of low-dose tocilizumab combined with glucocorticoid for the treatment of very-late-onset myasthenia gravis (VLOMG). Methods: We conducted a retrospective study in VLOMG patients who were administered intravenous methylprednisolone therapy and subsequently received low-dose oral corticosteroid, in combination with intravenous injection of tocilizumab given once every month for three months. Results: Five patients (mean age 75.0 ± 4.5 years) were included, and all of them were new-onset, and anti-acetylcholine receptor (AChR) antibody-positive generalized MG. The Quantitative Myasthenia Gravis Scale (QMGS) and Myasthenia Gravis Activities of Daily Living (MG-ADL) scores before treatment were 15.4 ± 4.3 and 9.6 ± 2.3, respectively, and they exhibited a continuously decreasing trend after the first, second, and third injection of tocilizumab until 6 months after treatment. At 6 months post-treatment, the QMGS and MG-ADL scores were 5.0 ± 2.9 and 2.0 ± 1.2, respectively, and the difference between scores at baseline and 6-month follow-up was significant (P = 0.005 and P < 0.0001, respectively). No serious adverse drug reactions were reported in any patient during the study period. Discussions and Conclusion: The therapeutic efficacy of tocilizumab in VLOMG remains uncertain. The results from our study support the efficacy and safety of this combination treatment option for VLOMG, and strongly suggests the therapeutic potential of tocilizumab in VLOMG. However, considering the limitation of retrospective nature and small sample size in this study, prospective randomized controlled studies including a larger sample size of selected patients are needed to validate our results.

Spontaneously resolving late-onset ocular myasthenia related to COVID-19. A case report.

Myasthenia gravis (MG) is the most common disease of the neuromuscular junction disorders with bimodal distribution of age, which is often under-estimated in the elderly. Some clinical cases show an association between MG and COVID-19, since molecular mimicry between SARS-CoV-2 and AChR proteins could be responsible for the onset of the disease. We report a 77-year-old woman who developed right eyelid ptosis five days after COVID-19 infection. Positive serum anti-acetylcholine receptor antibodies allowed the diagnosis of myasthenia gravis. It should be noted that there were no significant decremental changes on 3 Hz repetitive motor nerve stimulation study, even for the affected orbicularis oculi muscle. Clinical and pathophysiological data suggest that inflammation during COVID-19 could trigger an overproduction of autoantibodies previously present in the body at a subclinical level. This is the first case of COVID-19 infection complicated by myasthenia gravis, to the best of our knowledge, that resolves spontaneously.

Studying the relationship between clinical features and mental health among late-onset myasthenia gravis patients.

BACKGROUND: Mental disorders are common comorbidities among individuals with neurological diseases, and the prevalence of depressive and anxiety-related symptoms in newly referred patients at neurology outpatient clinics is high. There have been few studies on the mental health of patients with late-onset myasthenia gravis (MG). AIM: To examine the relationship between clinical features and the mental health symptoms within late-onset MG patients. METHODS: A total of 105 patients diagnosed with MG were recruited consecutively from a neuromuscular outpatient clinic between December 2020 and February 2021. Patients were classified into two groups: early-onset MG (age at onset < 50 years, n = 63) and late-onset MG (age at onset ≥ 50 years, n = 42). Social demographic data and information about marital status, education level, clinical symptoms, serum antibody levels, and therapies used were collected for all participants. Participants were also evaluated using the Myasthenia Gravis Composite scale, the Myasthenia Gravis Activities of Daily Living scale, the Myasthenia Gravis Quality of Life 15 (MG-QOL-15) questionnaire, the 17-item version of the Hamilton Depression Rating Scale (HAM-D) and the Hamilton Anxiety Rating Scale (HAM-A). The relationship between clinical features and mental health in late-onset MG patients was examined using multivariate logistic regression analyses. RESULTS: Late-onset MG patients were more prone to dyspnea, had higher levels of serum anti-acetylcholine receptor antibodies, and higher total scores on the MG-QOL-15, HAM-D, and HAM-A questionnaires, than early-onset MG patients had (P < 0.05). Among those with late-onset MG, female patients had higher total HAM-D and HAM-A scores than male patients had (P < 0.05). High scores on the QOL-15 questionnaire were associated with higher incidences of anxiety and depression, and the association was found to be independent after adjusting for confounding risk factors. In the late-onset subgroup, the areas under the receiver operating characteristic curves for the MG-QOL-15 score-based diagnostic accuracy for anxiety and depression state were 0.816 (P = 0.001) and 0.983 (P < 0.001), respectively. CONCLUSION: Higher MG-QOL-15 scores were a risk factor for anxiety and depression in late-onset MG, and women with late-onset MG were more likely to have anxiety and depression than men were.

Comorbidities in older patients with myasthenia gravis - Comparison between early- and late-onset disease.

BACKGROUND: Multimorbidity is an emerging challenge in older myasthenia gravis patients, which can have even greater impact on quality of life and outcome than symptoms of myasthenia. AIMS OF THE STUDY: We aimed to investigate comorbidities in older population and compare early-onset (EOMG) and late-onset (LOMG) myasthenia patients. METHODS: We investigated clinical information of patients from Oxford Myasthenia Centre age 50 or older. Data on 60 chronic disorders were extracted. RESULTS: We included 327 myasthenia patients (30.9% EOMG and 69.1% LOMG) with a median age of 70 years. Comorbidities were present in 94.5% of patients and accumulated with age. Hypertension (58.4% vs. 31.7%), hypercholesterolemia (41.2% vs. 23.8%), diabetes (24.8% vs. 11.9%), cataract (15.5% vs. 5.0%) and prostate disorders (15.0% vs. 2.0%) were more common in LOMG than EOMG, but there were no differences between 70 EOMG and 70 LOMG patients matched according to age and sex. CONCLUSIONS: Comorbidities in older patients with myasthenia are very common, increase with age, and do not differ between early- and late-onset disease.

Rituximab para el tratamiento de la miastenia grave generalizada: experiencia en la práctica clínica / Rituximab for the treatment of generalised myasthenia gravis: experience in clinical practice

Introducción y objetivos: El rituximab (RTX) es un anticuerpo monoclonal anti-CD20 que se ha utilizado en casos de miastenia grave (MG) refractaria. El objetivo de este trabajo es analizar la eficacia y la seguridad del RTX en la MG en la práctica clínica real en un hospital terciario. Pacientes y métodos:Se realiza un estudio retrospectivo de pacientes con MG tratados con RTX en nuestro centro de marzo de 2014 a septiembre de 2020. Se recogen datos demográficos, serológicos, tratamiento inmunomodulador previo, respuesta clínica y efectos adversos. Resultados: Veinte pacientes con MG –el 100%, generalizada: el 70%, MG de inicio tardío (LOMG), y el 30%, MG de inicio temprano (EOMG)– han recibido RTX (edad media: 66,8 años; 70%, varones). El 90% son seropositivos –16 con anticuerpos antirreceptor de la acetilcolina positivos y dos con anticuerpos antitirosincinasa muscular específica (anti-MuSK) positivos–. Todos habían fracasado con tratamientos previos: el 100% con esteroides, el 100% con inmunoglobulinas intravenosas y/o con plasmaféresis, el 55% con otros inmunosupresores (25%, un inmunosupresor previo; 10%, dos; 15%, tres; y 5%, cuatro) y el 35% con timectomía. Tras el RTX, presentó respuesta clínica el 75% de los pacientes (12 pacientes, remisión completa con posibilidad de la retirada de los esteroides sin recurrencia; y tres parcial, con posibilidad de la reducción de la dosis de esteroides) y fracaso terapéutico el 25%; en todos estos casos se retiró el RTX. El 100% de los pacientes anti-MuSK+ y el 92,8% de los de LOMG presentaron respuesta al RTX, mientras que el 66% de los pacientes con EOMG fracasaron. Sólo tres pacientes presentaron efectos adversos, todos leves, que no requirieron la retirada del RTX. Conclusión: En nuestra experiencia, el rituximab es un tratamiento seguro y eficaz en la MG generalizada agresiva con anticuerpos anti-MuSK o de inicio tardío (LOMG).(AU)

Introduction and aims: Rituximab (RTX) is an anti-CD20 monoclonal antibody that has been used in cases of refractory myasthenia gravis (MG). The aim of this work is to analyse the efficacy and safety of RTX in MG in real clinical practice in a tertiary hospital. Patients and methods: A retrospective study was conducted with patients with MG treated with RTX in our centre from March 2014 to September 2020. Demographic and serological data, together with information about previous immunomodulatory treatment, clinical response and adverse effects are collected. Results: Twenty patients with MG – 100% generalised: 70% late-onset MG (LOMG) and 30% early-onset MG (EOMG) – were given RTX (mean age: 66.8 years; 70% male). A total of 90% are seropositive, 16 of them with positive anti-acetylcholine receptor antibodies and two with positive muscle-specific tyrosine kinase (anti-MuSK) antibodies. All had failed previous treatments: 100% with steroids, 100% with intravenous immunoglobulins and/or plasmapheresis, 55% with other immunosuppressants (25% with one previous immunosuppressant, 10% with two, 15% with three and 5% with four) and 35% with thymectomy. After RTX, 75% of patients showed a clinical response (12 patients with complete remission and the possibility of steroid withdrawal without recurrence; and three patients with partial remission and the possible reduction of steroid dosage) and 25% therapeutic failure; in all these cases RTX was withdrawn. All the anti-MuSK+ patients (100%) and 92.8% of the LOMG patients responded to RTX, while 66% of EOMG patients failed. Only three patients reported adverse effects, all of which were mild and did not require RTX withdrawal. Conclusion: In our experience, rituximab is a safe and effective treatment in aggressive generalised MG with anti-MuSK or late-onset MG (LOMG).(AU)

A Diagnostic Dilemma of Dysphonia: A Case Report on Laryngeal Myasthenia Gravis.

An autoimmune neuromuscular junction disorder, myasthenia gravis, occurs when antibodies are produced against postsynaptic membrane acetylcholine receptors. Late-onset myasthenia gravis, a rare variant of the disease found in the elderly, has become a diagnostic challenge on account of its atypical presentation. We proffer a case of a 60-year-old man that presented with progressive dysphonia and weakening of cough, which was eventually followed by difficulty in swallowing and nasal regurgitation. Examination and laboratory workup came out unremarkable apart from a positive acetylcholine receptor antibody test, due to which a diagnosis of laryngeal myasthenia, an uncommon presentation of late-onset myasthenia gravis was made. Following treatment with pyridostigmine and prednisolone saw a relief of the active complaints. This article highlights the need for physicians to stay alert and have a high suspicion of such probability for timely diagnosis.

Clinical profile and impact of comorbidities in patients with very-late-onset myasthenia gravis.

INTRODUCTION/AIMS: The purpose of this study was to evaluate the clinical profile of myasthenia gravis (MG) in older patients and determine the impact of medical comorbidities on their MG status and outcome. METHODS: This was a retrospective chart review of patients with a symptom onset of MG at or after 65 years of age. Correlations were made between demographics, clinical characteristics, the Myasthenia Gravis Foundation of America (MGFA) severity scale scores, and Myasthenia Gravis Impairment Index (MGII) scores with two outcome measures: MGFA Post-Intervention Status (MGFA-PIS) and Simple Single Question (SSQ). RESULTS: The study population included 109 patients, with 90 of them having more than one follow-up visit. Their mean age was 75.3 ± 6.9 years and sex distribution was even. Of these patients, 67.7% had generalized MG. Nine-one percent of patients had one comorbidity. None of the demographic factors or comorbidities showed an association with MGFA-PIS, SSQ, or MGII after correction for multiple comparisons. Seventy-one percent of the patients improved with treatment, 12.4% remained unchanged, and 16.6% showed worsening at their last follow-up visit. DISCUSSION: Our study shows that patients with very-late-onset MG had a good prognosis and treatment response. None of the comorbidities had an impact on the severity of myasthenic symptoms or on outcome in these patients.

The associations of HLA-DRB1 gene polymorphisms with late-onset myasthenia gravis: a meta-analysis.

BACKGROUND: Late-onset myasthenia gravis (LOMG) is one of the major subgroups of the MG. Intensive evidence suggested that polymorphisms in HLA-DRB1 gene were associated with LOMG risk, but the results remained inconsistent. Therefore, a meta-analysis is conducted to make a more precise evaluation between HLA-DRB1 alleles and LOMG. METHODS: The PubMed, EMBASE, Cochrane library, Chinese National Knowledge Infrastructure (CNKI), and Wan Fang and Technology of Chongqing (VIP) Database were searched for eligible studies. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were applied to assess the association between HLA-DRB1 alleles and LOMG. RESULTS: A total of 11 studies involving 5513 people were included in our meta-analysis. The results showed that DRB1 07 and 0403 alleles were risk factors for LOMG (1.83 [1.12, 2.98], P = 0.02; 7.05 [2.62, 18.92], P = 0.0001, respectively), while DRB1 0301 and 1301 alleles were identified as protective factors for LOMG (0.44 [0.31, 0.62], P < 0.00001; 0.38 [0.23, 0.62], P = 0.0001, respectively). As for the HLA-DRB1 04 and 14 alleles, our subgroup analysis showed that there were significant associations between these alleles and LOMG in Caucasians (2.21 [1.14, 4.27], P = 0.02; 2.82 [1.29, 6.14], P = 0.009, respectively). CONCLUSIONS: These results confirmed the association of DRB1 alleles (0301, 04, 0403, 07, 1301, and 14) and LOMG, which might provide potential promising biomarkers for prediction of LOMG risk.

Clinical differences of early and late-onset myasthenia gravis in 985 patients.

Objective: The clinical differences of early-onset myasthenia gravis (EOMG) and late-onset MG (LOMG) have not been elucidated in China. In order to clarify this, a retrospective study was conducted in 985 MG patients, whose disease duration was longer than 3 years. Methods: These patients were separated into EOMG and LOMG according to the onset age of 50 years. The clinical differences including demographics, clinical features, thymus abnormalities and comorbidities of EOMG and LOMG patients were analyzed. Results: Results indicated that 485 were males and 500 were females, 714 were EOMG and 271 were LOMG. Female was more common in EOMG and male was more common in LOMG (p = 0.003). The peak onset age was 0-4 years in EOMG and 55-59 years in LOMG. Ocular MG (OMG) was more common in EOMG and generalized MG (GMG) was more common in LOMG (p = 0.004). The transformation rate of OMG to GMG was higher in LOMG (p = 0.002). The positive incidence of repetitive nerve stimulation (RNS) was higher in EOMG (p = 0.026). Thymoma was more frequent in LOMG (p = 0.017) and thymic hyperplasia was more frequent in EOMG (p < 0.001). Hyperthyroidism was more common in EOMG (p = 0.017) and diabetes was more common in LOMG (p < 0.001). Conclusion: These results have potential significance for the recognition of clinical features and the determination of management strategies in EOMG and LOMG.

Late-onset myasthenia gravis is predisposed to become generalized in the elderly.

OBJECTIVE: The continuous increase in the number of patients presenting with late-onset myasthenia gravis (LOMG) underscores the need for a better understanding of the clinical course and the establishment of an optimal therapeutic strategy. We aimed to clarify factors associated with clinical outcomes in LOMG. METHODS: We retrospectively reviewed the clinical profiles of 40 patients with early-onset MG (EOMG) (onset age: 49 years or younger), 30 patients with non-elderly LOMG (onset age: 50-64 years), and 28 patients with elderly LOMG (onset age: 65 years or older) and compared the subgroups according to onset age and thymus status. The evaluated parameters were MGFA classification before treatment, MG-ADL score, complicating diseases, antibody titer, treatment, and MGFA post-intervention status. RESULTS: Elderly LOMG patients showed transition to generalized symptoms at a higher frequency and underwent thymectomy less frequently than EOMG and non-elderly LOMG patients (p < 0.001). The frequencies of crisis and plasmapheresis were significantly lower in thymectomized LOMG patients without thymoma than in thymectomized LOMG patients with thymoma or non-thymectomized LOMG patients (p < 0.01, P < 0.05, respectively). However, the outcome was not significantly different. All of the thymectomized LOMG patients without thymoma presenting with hyperplasia or thymic cyst had a favorable clinical course. CONCLUSIONS: Our study showed that elderly LOMG patients are more prone to severity, suggesting that they require aggressive immunomodulatory therapy.

Immunoadsorption therapy in late-onset myasthenia gravis / 中华肾脏病杂志

Objective To investigate the removal effect of immunoadsorption (IA) on associated antibodies and the efficacy in late-onset myasthenia gravis (MG). Methods A total of 25 late-onset MG patients were randomly selected to enroll in this study. IA therapy was given to 10 patients (IA group), while immunoglobin (0.4 g·kg-1·d-1) was administrated to the other 15 patients for 5 days(Ig group). The titers of Titin antibody (Titin-ab), acetylcholine receptor antibody (AchR-ab) and presynaptic membrane antibody (PrsmR-ab) were detected before and after the treatment. Quantitive MG (QMG) score was assessed before and immediately after the entire course of treatment. The clinical efficacy, the duration of respiratory support and in-hospital were compared between two groups. The correlation between three antibodies and QMG score was also analyzed. Results Compared with that before treatment, the Titin-ab PIN values, the AchR-ab PIN values, and the PrsmR-ab P/N values of IA group were all decreased significantly after treatment (P<0.05, respectively). The P/N value of Titin-ab in IA group was decreased by 54.7%～3.5%, which was significantly higher than that in Ig group(19.9%±3.1%) (P<0.01). QMG score reduced by 42.4%± 4.2% and 23.8%±3.7% in IA group and Ig group respectively (P<0.01, respectively). Symptoms were effectively ameliorated by both treatments, but the effective power of IA group was higher than that of Ig group (70% vs 40%, P<0.05). Remission time of IA group was significantly shorter than that of Ig group [(5.38±0.42) d vs (8.4±1.54) d, P=0.008), so was the duration of in-hospital [(13.50±0.50) d vs (16.50±0.50) d, P<0.05). The number of respiratory support in IA group was less than that in Ig group (1/10 vs 6/15, P<0.05). By the Pearson correlation analysis, the decrease of Titin-ab showed a better longitudinal correlation with the decrease of QMG score than the other two antibodies (r=0.6315, P<0.01). Conclusion IA can rapidly and effectively clear the pathogenic antibodies of late-onset MG patients and its short-term clinical efficacy is better than immunoglobin.