Treatment with infliximab or azathioprine negatively impact the efficacy of hepatitis B vaccine in inflammatory bowel disease patients

Background and AimImmunization against hepatitis B virus (HBV) infection is recommended in patients with inflammatory bowel disease (IBD), particularly in those under immunosuppressive therapy. Limited data are available about IBD patient's response to HBV vaccination. We assessed the response rate to HBV vaccination in IBD patients and evaluated the impact of different factors on the efficacy of HBV vaccination. MethodsAnti-HBs titers were measured in a cohort of IBD patients under treatment with infliximab and/or azathioprine. Vaccination was considered efficient when anti-HBs titers were higher than 10IU/L. ResultsWe have identified 217 patients with IBD under infliximab who were vaccinated for hepatitis B, 172 (79%) with Crohn's Disease and the remaining with ulcerative colitis; 114 patients (53%) were male and mean age was 3311 years. Overall, HBV vaccine was successful in 164 (76%) patients. Only 14 patients were vaccinated after infliximab was initiated, and only two of them had antibody levels above 10IU/L. Among the patients that received vaccination before the beginning of infliximab, 88% of those who were vaccinated before starting azathioprine developed antibodies in contrast to 55% who already were under azathioprine. In multivariable analysis, treatment with infliximab (adjusted OR [95% CI]: 17.642 [8.514-33.937]) and with azathioprine (adjusted OR [95% CI]: 3.344 [1.653-9.145]) were the only factors associated with weaker response to HBV vaccination. ConclusionThe response rate to the standard HBV vaccination in IBD patients is low mainly in those treated with infliximab and/or azathioprine.