COVID‐19 in patients with myasthenia gravis: Epidemiology and disease course

Businaro, Pietro; Vaghi, Gloria; Marchioni, Enrico; Diamanti, Luca; Arceri, Sebastiano; Bini, Paola; Colombo, Elena; Cosentino, Giuseppe; Alfonsi, Enrico; Costa, Alfredo; Ravaglia, Sabrina; Mallucci, Giulia; Ballante, Elena; Franciotta, Diego; Gastaldi, Matteo

INTRODUCTION/AIMS: Coronavirus disease 2019 (COVID‐19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, has become a global pandemic. Patients with myasthenia gravis (MG), often treated with immunosuppressants, might be at higher risk of developing COVID‐19 and of demonstrating a severe disease course. We aimed to study prevalence and describe features of COVID‐19 in MG patients. METHODS: In May 2020, we conducted telephonic interviews with MG patients followed at our referral center. We collected structured data regarding MG and COVID‐19, which was diagnosed as probable or confirmed according to the European Centre for Disease Prevention and Control case definition. We compared confirmed‐COVID‐19 prevalence calculated from the beginning of the pandemic in MG patients with that of the overall Pavia district. RESULTS: We interviewed 162 MG patients (median age, 66 y; interquartile range 41‐77; males 59.9%), 88 from the Pavia district. Three patients had SARS‐CoV‐2‐confirmed by polymerase chain reaction and eight had probable‐COVID‐19. In the Pavia district, the prevalence of confirmed‐COVID‐19 among MG patients (1/88, 1.14%) and overall population (4777/546 515, 0.87%) did not differ (P = .538). Higher Myasthenia Gravis Foundation of America clinicalclass and the need for recent rescue treatment, but not ongoing immunosuppressive treatments, were associated with COVID‐19 risk. Of 11 MG patients with probable/confirmed‐COVID‐19, 3 required ventilator support, and 2 elderly patients died of COVID‐19 respiratory insufficiency. Only 1 of11 patients experienced worsening MG symptoms, which improved after increasing their steroid dose. DISCUSSION: The risk of COVID‐19 in MG patients seems to be no higher than that of the general population, regardless of immunosuppressive therapies. In our cohort, COVID‐19 barely affected MG course.