Comparative outcomes in chronic lymphocytic leukemia patients with and without myasthenia gravis: A propensity score–matched analysis.

e19019 Background: Chronic lymphocytic leukemia (CLL) is commonly associated with autoimmune complications, most of which are hematological in nature. Rarely, non-hematological autoimmune disorders such as myasthenia gravis (MG) have been reported to occur in patients with CLL, with only a small number of cases described in the literature since the 1960s. Despite this, the clinical impact remains poorly characterized, particularly regarding outcomes such as mortality, hospitalization, infectious risk, and treatment patterns. Methods: A retrospective cohort study was conducted using electronic health record data to identify adults with CLL, with and without MG. Propensity score matching was performed using age, sex, and additional clinical variables to create two balanced cohorts. Outcomes assessed included mortality, hospitalizations, sepsis/bacteremia, and use of immunomodulatory therapies. Statistical analyses included Kaplan–Meier curves, log-rank tests, and Cox proportional hazards modeling. Results: After matching, each cohort contained 171 patients with similar demographics. Mortality risk was 16.4% in CLL patients and 18.1% in CLL + MG patients (risk difference −0.018; 95% CI: −0.098 to 0.063; p = 0.668). Hospitalization occurred in 29.2% of CLL patients versus 39.2% in CLL + MG patients (risk difference −0.099; 95% CI: −0.199 to 0.001; p = 0.053). Rates of sepsis/bacteremia were 17.0% versus 20.5% (risk difference −0.035; 95% CI: −0.118 to 0.048; p = 0.405). Use of acetylcholinesterase inhibitors was significantly higher in the MG group (46.2% vs. 5.8%; risk difference −0.404; 95% CI: −0.486 to −0.321; p < 0.001), as was corticosteroid usage (74.9% vs. 56.1%; risk difference −0.187; 95% CI: −0.286 to −0.088; p < 0.001) and steroid-sparing agents (15.2% vs. 5.8%; risk difference −0.094; 95% CI: −0.158 to −0.029; p = 0.005). Kaplan–Meier analysis showed no significant difference in overall survival between groups (mortality, log-rank p = 0.738), but survival probability declined more markedly with MG in specific therapeutic subgroups. Conclusions: Patients with both CLL and MG exhibit higher rates of immunosuppressive and immunomodulatory therapy use and trends toward increased mortality and hospitalizations, though most results are not statistically significant except for specific medication exposures. These findings highlight the need for tailored management and further research for this clinical population.