Hepatitis B Reactivation in Biologic‐Treated Moderate‐to‐Severe Psoriasis: A Real‐World Cohort Study With 534 Patient‐Years of Follow‐Up

Background Psoriasis vulgaris is a chronic immune‐mediated inflammatory disease frequently requiring long‐term biologic therapy. Although biologics targeting TNF‐α and interleukin pathways have revolutionized disease management, they may disrupt antiviral immune surveillance and trigger hepatitis B virus (HBV) reactivation in individuals with prior HBV exposure. Data on the long‐term safety of newer agents—particularly IL‐17 and IL‐23 inhibitors—in patients with prior HBV exposure remain limited. Objectives To evaluate longitudinal changes in HBV serological and virological markers and determine the frequency of HBV reactivation among patients with psoriasis vulgaris receiving biologic therapies in routine clinical practice. Methods This retrospective, single‐center study included adult patients treated with biologics between December 2019 and January 2025. HBV serology (HBsAg, anti‐HBs, and anti‐HBc) and HBV‐DNA were assessed at baseline and every 6 months, with 3‐monthly monitoring for anti‐HBc–positive patients from electronic hospital records. Results A total of 345 biologic treatment episodes in 311 patients, corresponding to 534.3 patient‐years of exposure, were analyzed. Biologic therapies included secukinumab (33%), risankizumab (24.6%), guselkumab (17.7%), ixekizumab (15.4%), adalimumab (4.1%), certolizumab pegol (2.9%), and ustekinumab (1.7%). Anti‐HBc positivity was identified in 42 treatment episodes (12.2%), of whom 93% received antiviral prophylaxis. Four HBV reactivation events (9.5%) were observed—two during ixekizumab, one during secukinumab, and one during risankizumab therapy—without progression to clinical hepatitis. The incidence of HBV reactivation among anti‐HBc–positive patients was 5.42 per 100 patient‐years. Conclusions In this real‐world cohort, HBV reactivation occurred in a clinically meaningful proportion of patients with prior HBV exposure (9.5%), presenting exclusively virologic or serologic reactivation without clinical hepatitis despite widespread antiviral prophylaxis. These findings underscore the need for individualized risk assessment and continuous virologic monitoring during biologic therapy and highlight the importance of further prospective studies to inform future clinical guidelines.