This study aimed to elucidate the prevalence of hepatitis B virus (HBV) serologic markers in Korean patients newly diagnosed with, but not yet treated for inflammatory bowel disease (IBD).

We prospectively enrolled 210 patients newly diagnosed with IBD (109 with ulcerative colitis and 101 with Crohn's disease). Hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) levels were measured and compared with those of 1,100 sex- and age-matched controls.

The prevalence of chronic HBV infection (positive HBsAg, positive anti-HBc, and negative anti-HBs results) and past infection (negative HBsAg, positive anti-HBc, and positive or negative anti-HBs results) were not significantly different between the patients and controls (chronic HBV infection: IBD, 3.8% vs. control, 4.9%, P=0.596; past infection: IBD, 26.2% vs. control, 28.8%, P=0.625). The patients with IBD aged <20 years were at a higher susceptibility risk (nonimmune) for HBV infection than the controls (IBD, 41.5% vs. control, 22.4%; P=0.018). In the multivariate analysis, an age of <20 years (P=0.024) and symptom duration of ≥12 months before diagnosis (P=0.027) were identified as independent risk factors for nonimmunity against HBV infection.

The patients newly diagnosed with IBD were susceptible to HBV infection. The frequency of nonimmunity was high, especially in the patients aged <20 years and those with a longer duration of symptoms before diagnosis. Therefore, it is necessary to screen for HBV serologic markers and generate a detailed vaccination plan for patients newly diagnosed with IBD.