Clinical Characteristics of Myasthenia Gravis Patients with COVID-19 in Guangxi, China: A Case–Control Study

PURPOSE: With the adjustment of prevention strategies in December 2022, coronavirus disease 2019 (COVID-19) became widely prevalent in China. This study is aimed to describe the clinical characteristics of myasthenia gravis (MG) patients with COVID-19 and identify risk factors of exacerbation in MG patients with COVID-19 in Guangxi. PATIENTS AND METHODS: A total of 489 MG patients and 587 control subjects in Guangxi during the COVID-19 pandemic were enrolled in this case–control study. After contacting the participants, the clinical data of MG patients and the control group were analyzed. The clinical characteristics of MG patients with COVID-19 were described. Multivariable logistic regression analysis was used for discovering independent risk factors of MG exacerbation in the patients with MG and COVID-19. RESULTS: A total of 311 (75.30%) MG patients and 428 (72.91%) control subjects were infected with COVID-19, and 64.31% of MG patients with COVID-19 were women. The median age at the time of interview was 41 (IQR: 28, 54) years old, and median onset age was 36 (IQR: 24, 51), both of which were lower than those in MG patients without COVID-19. MG duration was 24 (IQR: 9, 72) months. About 44.69% of patients were generalized MG (GMG). About 11.90% of MG patients with COVID-19 showed severe COVID-19 symptoms and the duration of symptomatic COVID-19 was 9.57 ± 6.79 days, higher than those in the control group. About 35.69% MG patients with immunosuppressive drugs were infected with COVID-19, which is higher than those in the non-infected MG patients (21.57%). A total of 120 (38.59%) MG patients with COVID-19 had comorbidities. About 21 (20.19%) of the 104 MG patients without vaccination showed severe COVID-19 symptoms. Multivariable logistic regression analysis showed that baseline MG activities of daily living profile (MG-ADL, OR 1.280, 95% CI: 1.010–1.621, p = 0.041), duration of COVID-19 (OR 1.158, 95% CI: 1.100–1.220, p < 0.001), GMG (OR 2.331, 95% CI: 1.228, 4.426, p = 0.010), and lack of COVID vaccination (OR 2.075, 95% CI: 1.152, 3.738, p = 0.015) were independent factors of exacerbation in MG patients with COVID-19. CONCLUSION: MG patients with immunosuppressive drugs, younger onset, longer MG duration, or comorbidities are more susceptible to COVID-19. The baseline MG-ADL, duration of symptomatic COVID-19, GMG, and lack of COVID-19 vaccination are independent risk factors of exacerbation in MG patients with COVID-19.