[Clinical characteristics and prognosis of immune checkpoint inhibitor-associated myasthenia gravis]

The clinical data and follow-up outcomes of 9 patients diagnosed with immune checkpoint inhibitor (ICI)-associated myasthenia gravis (MG) admitted to Henan Provincial People's Hospital from January 2021 to October 2024 were collected retrospectively to analyze their clinical characteristics and prognosis. Nine patients were enrolled, including 4 males and 5 females, aged [M (Q₁, Q₃)] 69 (55, 77) years. All patients had tumors and had received ICI treatment. The time from the start of ICI treatment to the occurrence of MG symptoms or aggravation of the condition was 26 (20, 39) d. Seven patients were classified Myasthenia Gravis Foundation of America Clinical Classification (MGFA) Ⅲ-Ⅴ. All 9 patients had increased creatine kinase and transaminase. Troponin was measured in 5 patients, and all showed elevated levels. ICI therapy was discontinued in all patients at the onset or exacerbation of MG symptoms, and they subsequently received immunomodulatory therapy with pyridostigmine combined with glucocorticoids and/or intravenous immunoglobulin. Symptoms improved in 7 patients and 2 patients showed poor therapeutic effect. The follow-up time was 12.0 (4.5, 16.5) months, and 2 patients died due to the progression of MG superimposed on underlying diseases at the end of the follow-up. ICI-related MG mostly occurs in the early stage of ICI treatment, and is characterized by severe symptoms, rapid progression, and easy complications with myositis/myocarditis. Active initiation of acetylcholinesterase inhibitors combined with immunotherapy can significantly improve outcomes.