title: Treatment with infliximab or azathioprine negatively impact the efficacy of hepatitis B vaccine in inflammatory bowel disease patients.
abstract: OBJECTIVE
  Immunization 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.
  
  
  METHODS
  Anti-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 10 IU/L.
  
  
  RESULTS
  We 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 33 ± 11 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 10 IU/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.
  
  
  CONCLUSIONS
  The response rate to the standard HBV vaccination in IBD patients is low mainly in those treated with infliximab and/or azathioprine.
authors.affiliation: Gastroenterology Department, Faculty of Medicine, Hospital de São João, Porto, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Andrade
authors.affiliation: Gastroenterology Department, Faculty of Medicine, Hospital de São João, Porto, Portugal.|Department of Biochemistry (U38-FCT), Faculty of Medicine, University of Porto, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Santos-Antunes
authors.affiliation: Gastroenterology Department, Faculty of Medicine, Hospital de São João, Porto, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Rodrigues
authors.affiliation: Gastroenterology Department, Faculty of Medicine, Hospital de São João, Porto, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Lopes
authors.affiliation: Gastroenterology Department, Faculty of Medicine, Hospital de São João, Porto, Portugal.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Macedo
mesh_terms: D000293:Adolescent; D000328:Adult; D001379:Azathioprine / Q000008:administration & dosage / Q000009:adverse effects*; D003093:Colitis, Ulcerative / Q000188:drug therapy* / Q000276:immunology*; D003424:Crohn Disease / Q000188:drug therapy* / Q000276:immunology*; D004347:Drug Interactions; D005260:Female; D005765:Gastrointestinal Agents / Q000008:administration & dosage / Q000009:adverse effects*; D006509:Hepatitis B / Q000517:prevention & control*; D006510:Hepatitis B Antibodies / Q000097:blood*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects*; D000069285:Infliximab / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D055815:Young Adult
chemical_list: D005765:Gastrointestinal Agents; D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D007166:Immunosuppressive Agents; D000069285:Infliximab; D001379:Azathioprine
keywords: HBV vaccine efficacy; IBD: clinical trials < gastroenterology; biologic therapies; hepatitis B; immunomodulators; virology < hepatology