title: QuantiFERON TB gold testing for tuberculosis screening in an inflammatory bowel disease cohort in the United States.
abstract: BACKGROUND
  Reactivation of latent Mycobacterium tuberculosis (TB) is a rare, yet devastating infectious complication associated with anti-tumor necrosis factor alpha (TNF-α) therapy. We evaluated the performance of the QuantiFERON TB Gold test (QFT-G) for TB screening in a cohort of inflammatory bowel disease (IBD) patients in the United States.
  
  
  METHODS
  We performed a retrospective, observational study of patients initiated and/or maintained on an anti-TNF-α agent in a single IBD referral center and recorded the frequency and the test results of QFT-G testing and the rate of TB reactivation.
  
  
  RESULTS
  512 QFT-G tests were done in 340 patients. Five patients (1.5%) had a positive, nine (2.7%) indeterminate, and 326 patients (95.8%) had a negative QFT-G. After a mean follow-up of 17 months there was one case of TB reactivation (0.3%). The use of immunosuppressive therapy or anti-TNF therapy at the time of testing did not affect the results of the QFT-G testing. Test-retest had substantial concordance (κ = 0.72). 25% of patients (n = 85) had TST testing. Concordance between the TST and QFT-G was found to be moderate (κ = 0.4152, P = 0.0041).
  
  
  CONCLUSIONS
  Most patients with negative QFT-G tolerated anti-TNF therapy with no evidence of TB reactivation. Concomitant use of immunosuppressive therapy or anti-TNF did not seem to affect QFT-G results. One patient had an indeterminate QFT-G while on infliximab and later developed miliary TB. Concordance with TST is moderate.
authors.affiliation: Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
authors.forename: Bashar J
authors.initials: BJ
authors.lastname: Qumseya
authors.forename: Ashwin N
authors.initials: AN
authors.lastname: Ananthakrishnan
authors.forename: Sue
authors.initials: S
authors.lastname: Skaros
authors.forename: Michael
authors.initials: M
authors.lastname: Bonner
authors.forename: Mazen
authors.initials: M
authors.lastname: Issa
authors.forename: Yelena
authors.initials: Y
authors.lastname: Zadvornova
authors.forename: Amar
authors.initials: A
authors.lastname: Naik
authors.forename: Lilani
authors.initials: L
authors.lastname: Perera
authors.forename: David G
authors.initials: DG
authors.lastname: Binion
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology*; D055985:Latent Tuberculosis / Q000139:chemically induced / Q000175:diagnosis* / Q000382:microbiology; D008297:Male; D008403:Mass Screening; D009169:Mycobacterium tuberculosis / Q000472:pathogenicity*; D012189:Retrospective Studies; D014374:Tuberculin Test; D014409:Tumor Necrosis Factor-alpha / Q000009:adverse effects*; D014481:United States
chemical_list: D014409:Tumor Necrosis Factor-alpha