Hepatitis B Virus Reactivation Induced by Infliximab Administration in a Patient with Crohn's Disease

A 47-year-old man diagnosed with Crohn's disease was treated with infliximab. He tested negative for hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs) but positive for anti-HB core antibody (anti-HBc). He tested positive for hepatitis B virus (HBV-) DNA 3 months after treatment and was administered entecavir. HBV-DNA test showed negative results 1 month later. ALT was persistently within the normal range, and HBV-DNA was persistently negative thereafter despite the continuation of infliximab every 8 weeks. In our hospital, 14 patients with inflammatory bowel disease, who tested negative for HBsAg, were treated with infliximab; 2 of them tested positive for anti-HBs and/or anti-HBc, and HBV reactivation was observed in 1 patient (the present patient). The present case and these findings highlight that careful follow-up is needed in patients with inflammatory bowel disease treated with infliximab who test positive for anti-HBc and/or anti-HBs.