title: The impact of immunosuppressive therapy on QuantiFERON and tuberculin skin test for screening of latent tuberculosis in patients with inflammatory bowel disease scheduled for anti-TNF therapy.
abstract: OBJECTIVE
  Patients with inflammatory bowel disease (IBD) should be routinely screened for latent tuberculosis (LTB) before starting anti-TNF therapy in order to prevent reactivation of LTB. Besides tuberculin skin test (TST), QuantiFERON-TB Gold In-Tube (QFT-G-IT) has gained wide acceptance as a screening strategy for LTB in IBD, although it may be negatively influenced by the prior use of immunomodulators (IMM) such as azathioprine or methotrexate. This study aimed to assess the impact of IMM on the TST and the QFT-G-IT for LTB screening in IBD patients scheduled for anti-TNF therapy.
  
  
  METHODS
  This observational, prospective, single-center study included consecutive IBD patients scheduled for anti-TNF therapy undergoing on the same day both TST and QFT-G-IT for screening of LTB, between 2008 and 2010. Patients with a prior history of known or suspicious (L)TB receiving (prophylactic) anti-TB therapy were excluded.
  
  
  RESULTS
  Seventy-five patients were finally included; 28 were treated with thiopurines (IMM group), while 47 (control group) received either 5-aminosalicylic acid (n = 41) or no therapy (newly diagnosed patients, n = 6). Overall, TST and QFT-G-IT were positive in 14 (18.7%) and 16 (21.3%) patients, respectively. There was no statistically significant difference between the two groups regarding the TST (p = 0.761) and QFT-G-IT (0.572) positivity. The overall concordance between the two tests was moderate (kappa = 0.584), being substantial in the IMM group (kappa = 0.700) and moderate in the control group (kappa = 0.498).
  
  
  CONCLUSIONS
  These preliminary results suggest that IMM may not have a significant impact on either QFT-G-IT or TST, although larger, prospective studies are certainly warranted.
authors.affiliation: Department of Gastroenterology, Evaggelismos Hospital , Athens , Greece.
authors.forename: Gerassimos J
authors.initials: GJ
authors.lastname: Mantzaris
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Tsironikos
authors.forename: Xanthipi
authors.initials: X
authors.lastname: Tzanetakou
authors.forename: Eirini
authors.initials: E
authors.lastname: Grispou
authors.forename: Pantelis
authors.initials: P
authors.lastname: Karatzas
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kalogeropoulos
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Papamichael
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D007167:Immunotherapy; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D055985:Latent Tuberculosis / Q000175:diagnosis*; D008297:Male; D008403:Mass Screening / Q000379:methods; D019804:Mesalamine / Q000627:therapeutic use*; D008875:Middle Aged; D011446:Prospective Studies; D014374:Tuberculin Test / Q000379:methods*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D007166:Immunosuppressive Agents; D014409:Tumor Necrosis Factor-alpha; D019804:Mesalamine
keywords: Anti-TNF therapy; QuantiFERON; inflammatory bowel disease; tuberculosis