Immune context and treatment timing associated with seizure freedom after rituximab in autoimmune limbic encephalitis

Seizure freedom represents a clinically meaningful outcome in autoimmune limbic encephalitis (ALE). Rituximab (RTX) is commonly used, but the factors associated with seizure outcomes remain unclear. We conducted a retrospective single-center cohort study including 107 adults with ALE and seizures treated between 2005 and 2024. Patients were stratified by RTX treatment, treatment timing, cerebrospinal fluid (CSF) findings, and seizure outcome. The primary endpoint was seizure freedom for ≥12 months. Overall, 72/107 patients (70.6%) achieved seizure freedom, including 18 RTX-treated patients. Earlier RTX initiation (< 12 months) was numerically associated with higher seizure freedom rates than later treatment (77.8% vs. 37.5%). In RTX-treated patients, positive CSF immune findings were associated with seizure freedom (100% vs. 62.5%). Combining early RTX initiation and positive CSF findings was associated with increased odds of seizure freedom. In multivariable analysis, RTX treatment was not independently associated with seizure freedom. These exploratory findings require prospective validation.