New-Onset Myasthenia Gravis Associated with SARS-CoV-2 Infection: A Systematic Review

This systematic literature review synthesizes available data from published case reports and case studies describing de novo myasthenia gravis (MG) following confirmed SARS-CoV-2 infection, focusing on clinical presentation, immunological characteristics, temporal relationship, management, and outcomes. The study addresses the following research question: What are the clinical, immunological, temporal, and outcome characteristics of de novo MG following SARS-CoV-2 infection based on published case reports and case studies? Following the PRISMA 2020 guidelines, the analysis included 44 studies describing 48 patients. The findings suggest that MG temporally associated with COVID-19 typically occurred within a relatively short latency period, with a median interval of 21 days. Most patients presented with generalized onset and were predominantly positive for AChR-Abs, consistent with the established clinical and serological profile of classical MG, in which AChR-Abs represent the most common subtype, particularly in generalized disease. MuSK and LRP4-positive cases were less frequent; ICU admission, myasthenic crisis, and respiratory failure were frequently reported. Importantly, most patients responded well to conventional MG therapies.