title: Normal response to vaccines in inflammatory bowel disease patients treated with thiopurines.
abstract: BACKGROUND
  Thiopurines are considered immunosuppressive agents and may be associated with an increased risk for infections. However, few inflammatory bowel disease (IBD) patients are appropriately vaccinated, and data on their ability to mount an immune response are vague. We evaluated the effects of the thiopurines, azathioprine (AZA) and 6-mercaptopurine (6-MP), on cellular and humoral immune responses in IBD patients.
  
  
  METHODS
  A prospective clinical investigation was conducted on IBD patients referred for thiopurine treatment. Immune competence was evaluated by assessing lymphocyte counts and phenotype, response to mitogen and antigen stimulation, immunoglobulin levels, and response to pneumococcal and tetanus vaccines (before treatment, week 0), and to Haemophilus influenza type b vaccine (at week 24).
  
  
  RESULTS
  Thirty-one Crohn's disease and 12 ulcerative colitis patients who completed at least 24 weeks of therapy were included. The posttherapy average 6-MP dose was 1.05 ± 0.30 mg/kg, and white blood cell counts had decreased significantly from baseline values (P < 0.002). The posttreatment response to mitogens and antigens and the immunoglobulin levels were unchanged. Responses to vaccines were normal both in thiopurine-naïve and thiopurine-treated patients, suggesting that these patients were immunologically intact while on thiopurine therapy and capable of generating normal immune responses in vivo.
  
  
  CONCLUSIONS
  There is no evidence for any intrinsic systemic immunodeficiency in IBD patients. Thiopurines at the doses used for treating IBD showed no significant suppressive effect on the systemic cellular and humoral immune responses evaluated. Thiopurine-treated IBD patients can be safely and efficiently vaccinated.
authors: Department of Gastroenterology and Liver Diseases, Tel Aviv Sourasky Medical Center, affiliated to tSackler Faculty of Medicine, Tel Aviv Israel. irisd@tasmc.health.gov.il
authors: Iris
authors: I
authors: Dotan
authors: Lael
authors: L
authors: Werner
authors: Sharon
authors: S
authors: Vigodman
authors: Shradha
authors: S
authors: Agarwal
authors: Jorge
authors: J
authors: Pfeffer
authors: Noya
authors: N
authors: Horowitz
authors: Lisa
authors: L
authors: Malter
authors: Maria
authors: M
authors: Abreu
authors: Thomas
authors: T
authors: Ullman
authors: Hanan
authors: H
authors: Guzner-Gur
authors: Zamir
authors: Z
authors: Halpern
authors: Lloyd
authors: L
authors: Mayer
mesh_terms: D000328:Adult; D001379:Azathioprine / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D005765:Gastrointestinal Agents / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D007108:Immune Tolerance / Q000187:drug effects*; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy* / Q000276:immunology; D007958:Leukocyte Count; D008297:Male; D015122:Mercaptopurine / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D014612:Vaccines / Q000276:immunology / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D005765:Gastrointestinal Agents; D007166:Immunosuppressive Agents; D014612:Vaccines; D015122:Mercaptopurine; D001379:Azathioprine