P.014 Immunotherapy responses of patients with suspected autoimmune-associated epilepsy with negative neural antibody testing

Background: In refractory epilepsy patients with possible autoimmune-associated (AAE) but negative antibody testing(-AB), immunotherapy trials (IMT) may still be pursued.The value of in such remains unclear. For this reason, we reviewed their responses. Methods: Retrospective review admitted to the Epilepsy Unit between (2018-2021) who received (IMT). All had (-AB) and (methylprednisolone (IVMP)-immune globulin (IVIg)-plasma exchange (PLEX)- rituximab).We considered responders when seizure reduction was ≥ 50%. Results: 14 identified. Of them, 50%(n=7) females. Median age (43.5 year. IQR= 28.75-63.25). 2 anti-seizure medications (ASM). onset (39.5 years. IQR=23.75-60.25).Median time from diagnosis until (15.5 months. IQR=12.75 -21.75). Patients either IVIG+IVMP (35.7%, n=5) or IVIG alone (28.5%, n=4) IVIG+IVMP+PLEX (21.4%, n=3) IVMP (7.1%, n=1) IVIG+IVMP+rituximab n=1). follow-up 25 months.Although early responses were common, sustained response at last only 21.4% (n=3). Factors confounding determination efficacy present all (e.g:concurrent changes ASM). Conclusions: Our findings suggest that suspected are largely unsuccessful. This suggests an insufficient therapeutic effect after alternatively,non-immune-mediated mechanisms causing type epilepsy. Critical evaluations (IMT)in cases needed.