Adults with myasthenia gravis who contracted COVID-19 were at twice the risk of hospitalization, ICU admission, and death based on data from a recent population-based study.
According to a recent population-based study using administrative health data in Ontario, Canada, adult participants with myasthenia gravis (MG) and who also contracted COVID-19 were twice the risk of hospitalization of matched controls.1 The patients with MG and infected with COVID-19 were also more at risk of ICU admission and death in comparison.
The MG cases had higher rates of ER visits, at 36.6% versus 24.4% for matched controls, as well as hospital admissions, at 30.5% in comparison to 15.1%. The ICU admissions were also higher, occurring at rates of 6.7% for the MG cases versus 3.9% for the matched controls, as was 30-day mortality (14.6% vs. 8.5%). In past research, there has been limited data on the health outcomes of COVID-19 infected people with MG, vaccine uptake, and safety.
Monica de Carvalho Alcantara, MD, PhD, Division of Neurology, UHN Toronto General Hospital, and colleagues presented the data at the 2022 American Association of Neuromuscular & Electrodiagnostic Medicine Annual Meeting, where between January 2020 and May 2021 there were 164 of 4411 (3.7%) MG cases and 669 of 22,055 (3.0%) controls who contracted COVID-19.1 Among the 3461 first doses of the COVID-19 vaccines in MG cases, less than 6 were hospitalized with an MG diagnosis within 30 days.
Of the eligible Ontario residents screened (n= 11,365,233), MG cases were matched according by age, sex and residential area with controls in the study. The mean age of the cohort was 67.7 years (±15.6), and more than half women (51.6%), and the majority were urban residents (88.0%). By August 2021, 80.3% MG cases versus 81.2% controls had received 2 vaccine doses, 3.1% MG cases versus 2.8% controls had one dose and 16.4% MG cases versus 15.8% controls were unvaccinated. Also in the study, vaccine uptake was high along with the negligible risk of severe MG exacerbations after receiving the immunization.
Previous research from Sonigra et al suggests that patients with MG are may be at a higher risk of developing a COVID-19 infection because of the associated immunosuppression resulting from long-term corticosteroid use.2 In another observational study from Rzepiński et al, 30 unvaccinated Polish patients with MG consulted in a neurological outpatient clinic had 11 patients with MG requiring hospitalization.3 Among the patients in the study group, 10 were identified as being infected with COVID-19. Of those that were infected, 7 experienced a mild course of symptoms with a quick recovery. As for the 3 remaining patients that had COVID-19, all had MG exacerbation reported.
Future research is needed to evaluate the infection of COVID-19 into the account of the ratio of patients vaccinated to unvaccinated MG patients, international differences, and the types of applied treatments available for patients.3