Clinical and Serological Profile of Myasthenia Gravis in the O’Higgins Region of Chile: A Regional Study

Myasthenia gravis (MG) is a rare, chronic, and progressive autoimmune disorder that can lead to significant disability in its advanced stages. This retrospective observational study aimed to estimate the prevalence of MG in the O'Higgins Region of Chile and provide a comprehensive characterization of patients' clinical profiles, including medical history, diagnostic findings, and therapeutic responses. A female predominance (n=47, 66.2%) was observed, and most patients showed abnormalities in electrophysiological studies. In nearly all cases, diagnosis was established through autoantibody testing, with acetylcholine receptor antibodies being the most frequently identified. The most frequent comorbidities included mood disorders, hypertension, and thyroid dysfunction. Most patients received cholinesterase inhibitors; corticosteroids were used in 74.6% of cases, and one-third were treated with conventional immunosuppressants. A smaller group received biological therapies such as rituximab or other newer agents, ravulizumab. Despite the range of available treatments, approximately 20% of patients exhibited a refractory disease course. MG is a disease with a multifaceted impact on patients' personal, social, and occupational lives. The findings of this study may support the development of targeted health policies aimed at improving comprehensive care for MG patients in Chile.