Analysis of infections and malignancy risks among patients with myasthenia gravis compared with matched controls in a US real-world setting

IntroductionMyasthenia gravis (MG) is a rare, debilitating autoimmune disease associated with pathogenic immunoglobulin G autoantibodies directed against components of the neuromuscular junction. The autoimmune nature of the disease and long-term immunosuppressive treatment may increase susceptibility to infections and malignancies, but studies investigating the association between MG and infections or malignancies remain scarce.MethodsWe conducted a retrospective, observational study using Optum's deidentified Market Clarity Data (Market Clarity) to evaluate the incidence rate (IR) of infections and malignancies in US-based patients with MG in a real-world setting. Adults with ≥2 diagnosis claims of MG were identified over a 2-year period (2016-2019) and propensity score (PS) matched with controls from the general population without MG. Patients with malignancies in the 1-year look-back period were excluded.ResultsPatients with MG (N = 5002) were compared with the PS-matched general population (N = 20,008). The IR of serious infections (primary outcome) was higher in the MG cohort compared with the general population (52.81 vs 31.46 per 1000 person-years [PY], respectively). IRs of opportunistic infections (87.48 vs 57.01 per 1000 PY) and infection-related death (3.98 vs 1.94 per 1000 PY) were also higher in the MG cohort compared with the general population. The overall rate of malignancy was higher in the MG cohort compared with the general population (73.55 vs 50.01 per 1000 PY, respectively).ConclusionsIn this analysis, patients with MG were more susceptible to serious infections, infection-related death, and malignancies.