A new study published in Muscle & Nerve found increased rates of COVID-19 complications and deaths in a cohort of patients with myasthenia gravis (MG).
The study aimed to investigate the impact of COVID-19 in a cohort of patients with MG and to determine the role of COVID-19 in myasthenia exacerbation and the long-term effects of COVID-19 infection on MG treatment.
The research team conducted a retrospective analysis of 39 patients with confirmed diagnoses MG and SARS-CoV-2 infection between March 1, 2020, and October 25, 2021, at Emory University, Atlanta, Georgia. Patients’ records were inquired for demographic data, MG history, and COVID-19 treatments and hospitalizations.
Eight of 39 patients were vaccinated at the time of infection, 30 were unvaccinated, and the vaccination status of 1 was unknown. The median age of patients was 52.6 years, and 27 received immunomodulatory treatments at the time of infection. Furthermore, 35 of 39 patients were symptomatic, 21 were hospitalized, and 7 required ventilation assistance.
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Additionally, MG exacerbations developed in 5 patients and were treated with therapeutic plasma exchange, intravenous immunoglobulin (IVIg), and prednisone taper. The results also suggest that 4 hospitalized patients died from COVID-related lung injuries, while no deaths were attributed to MG exacerbation. Moreover, no deaths were reported in fully vaccinated patients, and only one vaccinated patient was admitted to the ICU.
The authors emphasized that caution should be taken with antibiotics in treating bacterial pneumonia occurring with MG since 1 patient experienced exacerbation after receiving azithromycin. Moreover, IVIg is advised to be used with caution in patients with COVID-19 infection, given the risk of exacerbating thromboembolic complications, as observed in a patient.
“Our data complement earlier studies showing an approximately 10% mortality in unvaccinated patients with MG and COVID-19 infection, which is higher than that of the general population, as calculated by the US Centers for Disease Control and Prevention,” the authors wrote.
MG is a rare neuromuscular disease yet the most common condition affecting the neuromuscular junction in skeletal muscle. MG treatments might lead to several COVID-19 complications; for example, long-term steroids might worsen diabetes, which is one of the risk factors for poorer outcomes with COVID-19.
Earlier studies have reported severe COVID-19 complications in patients with MG, while larger studies conducted in Turkey and Czech Republic in the pre-vaccine era reported more severe complications (~11% mortality); however, many such cases were those where patients experienced mild illness and were mistakenly put in MG patient registries. Additionally, the COVID-19 Associated Risks and Effects in Myasthenia Gravis (CARE-MG) registry has reported a higher risk of MG exacerbation (40%) and mortality (24%) compared to previous studies.
Thomas EV, Bou G, Barton S, et al. COVID-19 infection in myasthenia gravis: clinical course and outcomes. Muscle Nerve. Published online Jun 16, 2023. doi:10.1002/mus.27919.