Prevalence of hepatitis-B viral markers in patients with inflammatory bowel disease in a hepatitis-B-endemic area: inadequate protective antibody levels in young patients.

Background: There are few data regarding the prevalence of hepatitis-B virus (HBV) markers in inflammatory bowel disease (IBD) patients in Korea, which is a hepatitis-B-endemic area. The aim of this study was to assess the prevalence of HBV markers in IBD patients in comparison with controls.

Methods: We enrolled 513 IBD patients [241 Crohn's disease (CD) and 272 ulcerative colitis (UC)] whose hepatitis-B surface antigen and anti-HBs levels were evaluated. Anti-HBc was assayed in 357 patients. These markers were compared with those of 1020 sex-matched and age-matched controls.

Results: Prevalence of hepatitis-B surface antigen in IBD patients was 3.7% and there was no significant difference between groups (CD 4.1%, UC 3.3%, control 4.4%, P=0.713). The frequency of effective vaccination against HBV (positive anti-HBs, without anti-HBc) was lower in IBD patients less than 30 years old compared with the same-aged controls (CD 43.3%, UC 48.5%, control 61.9%, P=0.002), whereas there was no difference between groups in subjects more than 30 years old. One third of IBD patients were at risk of susceptibility to HBV infection (nonimmune), particularly those less than 30 years old, compared with controls of the same age (CD 43.3%, UC 36.4%, control 21%, P<0.001). In IBD patients, multivariate analysis identified that age less than 30 years was an independent risk factor for nonimmune status.

Conclusions: IBD was not a risk factor for HBV infection even in endemic areas. However, many young IBD patients were susceptible to HBV infection. It is crucial to screen for HBV immunity and to implement a meticulous vaccination strategy for young Korean IBD patients.