title: Interferon-gamma release assay clarifies the effect of bacille Calmette-Guérin vaccination in Greek army recruits.
abstract: OBJECTIVE
  To compare the most recent commercial interferon-gamma release assay (IGRA), the QuantiFERON-TB Gold In-Tube (QFT-GIT), with the tuberculin skin test (TST) in Greek army recruits who were bacille Calmette-Guérin (BCG) vaccinated during childhood and had no history of tuberculosis (TB) exposure.
  
  
  METHODS
  We conducted a cross-sectional comparison study of 1750 young army recruits. TST was performed on all participants, while QFT-GIT was performed in all subjects with TST > 0 mm and in 18 TST-negative controls (TST = 0 mm).
  
  
  RESULTS
  Among the study subjects, 5.4% (96/1750) had TST indurations of >or=10 mm, and 3.4% (59/1750) had indurations of >or=15 mm. Among subjects with a positive TST, 11.4% (11/96) tested positive on QFT-GIT. All those with QFT-GIT positivity had TST indurations of >or=15 mm, and none of those with TST indurations of 10-14 mm were positive by QFT-GIT. The overall agreement between TST and QFT-GIT was poor (kappa = 0.02).
  
  
  CONCLUSIONS
  We found a significant discordance between TST and QFT-GIT in BCG-vaccinated Greek army recruits consistent with previous studies showing that BCG received after infancy produces false-positive TST reactions. Our findings underline the need for a two-step approach in diagnosing latent TB infection in all BCG-vaccinated individuals: initial TST screening, followed by an IGRA to confirm TST positivity.
authors.affiliation: Department of Pneumonology, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Katsenos
authors.forename: M
authors.initials: M
authors.lastname: Nikolopoulou
authors.forename: A K
authors.initials: AK
authors.lastname: Konstantinidis
authors.forename: C
authors.initials: C
authors.lastname: Gartzonika
authors.forename: A
authors.initials: A
authors.lastname: Gogali
authors.forename: I
authors.initials: I
authors.lastname: Margelis
authors.forename: A
authors.initials: A
authors.lastname: Tatsioni
authors.forename: A
authors.initials: A
authors.lastname: Mavridis
authors.forename: S H
authors.initials: SH
authors.lastname: Constantopoulos
authors.forename: G
authors.initials: G
authors.lastname: Daskalopoulos
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000293:Adolescent; D000328:Adult; D001500:BCG Vaccine / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D005260:Female; D006115:Greece; D006801:Humans; D007371:Interferon-gamma; D008297:Male; D008889:Military Personnel; D014374:Tuberculin Test / Q000379:methods*; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology; D055815:Young Adult
chemical_list: D000276:Adjuvants, Immunologic; D001500:BCG Vaccine; D007371:Interferon-gamma