Serological Assessment of Hepatitis in Patients with Inflammatory Bowel Disease in Taiwan: A Retrospective Cohort Analysis

Inflammatory bowel disease (IBD), comprising ulcerative colitis (UC) and Crohn's disease (CD), is a chronic, immune-mediated inflammatory disorder of the gastrointestinal tract. Immunosuppressive therapy administration increases the risk of hepatitis B virus (HBV) and hepatitis C virus (HCV) reactivation. This study aimed to investigate the hepatitis screening rate, serological status, and protective antibody levels among the Taiwanese IBD population. This single-center retrospective study included patients with IBD from January 2016 to December 2024. Hepatitis serological markers were analyzed. Patients were categorized into active HBV infection (HBsAg-positive), resolved HBV infection (HBsAg-negative and anti-HBc-positive), and non-HBV-infected groups, with prevalences of 7.5%, 32.5%, and 0.9%, respectively. This study included 347 patients with IBD (UC: 68.3%; CD: 31.7%), with a mean age of 47.1 ± 16.4 years. Patients born after 1984 demonstrated a significantly reduced HBsAg positivity (0.9% vs. 11.0%; <i>p</i> < 0.05) and resolved HBV infection (52.2% vs. 1.0%; <i>p</i> < 0.05). However, among non-HBV-infected individuals, only 42.0% had protective anti-HBs levels (≥10 mIU/mL), despite vaccination program initiation. In this study, we found an overall HBsAg positivity rate of 7.5% and an anti-HCV seropositivity rate of 0.9% in our IBD population. Taiwan's HBV vaccination program has effectively reduced the HBV prevalence. However, a significant proportion of vaccinated individuals lack sufficient protective antibody levels, thereby requiring continued HBV screening and booster vaccinations.