P914 Immunogenecity of Hepatitis B Vaccination in Patients with Ulcerative Colitis on Infliximab Monotherapy : A Prospective Comparative Study

Abstract

Abstract Background Hepatitis B virus (HBV) infection has been associated with chronic hepatitis and cirrhosis. Patients with inflammatory bowel disease (IBD) maybe at higher risk of HBV infection, especially those on biologic therapies. There is limited data on the effectiveness of HBV vaccination in patients with IBD receiving different types of IBD medications. This study intends to compare the effectiveness of HBV vaccine in patients with ulcerative colitis (UC) on Infliximab (IFX) compared to those on 5-aminosalicylic acid (5-ASA). Methods Patients with UC aged between 18-85 years were prospectively enrolled in the study. The patients were divided into two groups: group 1 ( patients with UC on 5-ASA) and group 2 (patients with UC on IFX). HBV vaccination was administered (20 mcg) following the standard regimen, and Hepatitis B serum antibody (HbsAb) titres were assessed three months after the final dose. The response to HBV vaccines was categorized as 'adequate' immune response (≥10 IU/L) and 'effective' immune response (≥100 IU/L). Results In our final analysis of 118 patients with UC, 54.2% were male, and 52.5% had extensive disease. HBsAb titer levels were significantly higher in the 5ASA group (126.7 ± 37.5) compared to the IFX group (55.5 ± 29.4). Stratifying HBsAb levels into two categories (≥10-99 IU/L and ≥100 IU/L) revealed a significantly greater proportion of subjects in the 5-ASA group with levels ≥100 IU/L (76.7%) compared to the IFX group (12.1%). Conversely, the IFX group showed a higher percentage of subjects with levels between 10-99 IU/L (87.9%) relative to the 5-ASA group (23.3%). Logistic regression analysis demonstrated that patients with UC receiving 5-ASA were 23.94 times more likely to exhibit HBsAb levels ≥100 compared to those on IFX (OR 23.94, 95% CI 8.89-64.49). Conclusion Immune response to hepatitis B vaccination in patient with ulcerative colitis on infliximab is attenuated compared to those on 5-ASA. Therefore emphasizing the importance of HBV vaccination for patients with IBD before starting anti-TNF therapy, especially infliximab, and advocating for screening is imperative in high risk countries.