Risk of Hepatitis B Virus Reactivation in Patients with Neurological Diseases Receiving Anti-CD20 Therapies

ABSTRACT Objective: Anti-CD20 therapies, including ocrelizumab, rituximab, and ofatumumab, are widely used in treating immune-mediated neurological diseases. However, these therapies may increase the risk of hepatitis B virus (HBV) reactivation, particularly in patients with prior HBV exposure. Despite the recognized preventive measures for managing HBV reactivation, specific data regarding the safety of anti-CD20 therapies in this context remain limited. This retrospective study aims to evaluate the risk of HBV reactivation among patients with neurological disorders treated with anti-CD20 therapies in a single-center cohort from Türkiye. Methods: We reviewed the records of 580 patients who received at least one dose of anti-CD20 therapies between July 2018 and March 2024. HBV serological markers were assessed at baseline and during follow-up. Patients were stratified based on HBV serostatus, and antiviral prophylaxis rates were documented. Serological follow-up data were reviewed for seroconversion. Results: Of the patients, 12.24% showed anti-HBc positivity, with higher rates in the ocrelizumab group (15.57%) compared to rituximab (8.08%) and none in the ofatumumab group. Among the anti-HBs positive group, the prophylaxis rate was 78%, while it was 100% in the anti-HBs negative side. No seroconversion cases were observed, regardless of prophylaxis status. Conclusions: Our findings indicate that anti-CD20 therapies do not pose a detectable risk of HBV reactivation in patients with immune-mediated neurological disorders, even when antiviral prophylaxis is not given to those who are anti-HBs positive. However, further prospective studies with larger cohorts must confirm these results and improve HBV management in this patient population.