P151 NONIMMUNITY AGAINST HEPATITIS B VIRUS IN PATIENTS WITH NEWLY DIAGNOSED INFLAMMATORY BOWEL DISEASE

Abstract

Currently, there are no data on the prevalence rate of hepatitis B virus (HBV) serologic markers in patients with newly diagnosed inflammatory bowel disease (IBD) in Korea, which is a hepatitis B endemic area. There has been controversy over the prevalence of HBV in patients with IBD. There are some reports that even if patients were inoculated with the HBV vaccine when they were toddlers, antibody titers are low when they were checked as adults because of the effect of immunosuppressant. However, these studies showed the effects of low titers are caused by external factors such as drugs; IBD itself was not mentioned as a factor. This study aimed to elucidate the prevalence of HBV serologic markers in Korean patients newly diagnosed with but not yet treated for inflammatory bowel disease (IBD). We prospectively enrolled 210 patients with newly diagnosed IBD (109 with ulcerative colitis [UC] and 101 with Crohn’s disease [CD]). 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. Patients with IBD aged <20 years were at a higher susceptibility risk (nonimmune) of HBV infection than the controls (IBD 41.5% vs. control 22.4%; P = 0.018). On multivariate analysis, patients of age < 20 years (P = 0.024) and with symptom duration > 12 months before diagnosis (P = 0.027) were identified as independent risk factors for nonimmunity against HBV. Newly diagnosed patients with IBD were susceptible to HBV infection. The frequency of nonimmune status was high, especially in patients < 20 years of age 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 newly diagnosed patients with IBD.