title: Discordance Between Tuberculin Skin Test and Interferon-γ Release Assay in Children Younger Than 5 Years Who Have Been Vaccinated With Bacillus Calmette-Guérin.
abstract: BACKGROUND
  Interferon-γ release assays (IGRAs) offer the possibility of improved detection of latent tuberculosis infection (LTBI).
  
  
  OBJECTIVE
  To analyze discordant tuberculin skin testing (TST) and IGRA results in ethnic Croatian children as old as 5 years for whom there is documented exposure to an adult with active tuberculosis (TB) and who have been vaccinated with Bacillus Calmette-Guérin.
  
  
  METHODS
  In specimens from our cohort individuals, we tested the performances of the QuantiFERON-TB Gold In-Tube (QFT-GIT) test and TST and analyzed discordant results.
  
  
  RESULTS
  At the TST cutoff value of 10 mm or greater, the estimated prevalence of M. tuberculosis infection was 18.1% (31/171) using TST and 15.2% (26/171) using QFT-GIT. The results of these 2 tests showed an overall concordance of 87.7%. There was no evidence that subjects' age correlated with discordant results.
  
  
  CONCLUSIONS
  The reasons for discordant results in young children are still unclear, which highlights the importance of further longitudinal studies to better understand the interpretation and any possible clinical implications of the results of these tests.
authors.affiliation: Department of Pulmonology, Allergology, Rheumatology, and Clinical Immunology, Children's Hospital Zagreb, Zagreb, Croati ipavic01@gmail.com.
authors.forename: Ivan
authors.initials: I
authors.lastname: Pavić
authors.affiliation: Department of Tuberculosis, Croatian National Institute of Public Health, Zagreb-Centar, Croatia.
authors.forename: Vera
authors.initials: V
authors.lastname: Katalinić-Janković
authors.affiliation: Department of Pulmonology, Allergology, Rheumatology, and Clinical Immunology, Children's Hospital Zagreb, Zagreb, Croati.
authors.forename: Jasna
authors.initials: J
authors.lastname: Čepin-Bogović
authors.affiliation: Department of Pulmonology, Allergology, Rheumatology, and Clinical Immunology, Children's Hospital Zagreb, Zagreb, Croati.
authors.forename: Arnes
authors.initials: A
authors.lastname: Rešić
authors.affiliation: Department of Clinical Laboratory Diagnosis, Srebrnjak Children's Hospital, Zagreb, Croatia.
authors.forename: Slavica
authors.initials: S
authors.lastname: Dodig
mesh_terms: D001500:BCG Vaccine / Q000627:therapeutic use*; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D059425:Interferon-gamma Release Tests; D008297:Male; D017063:Outcome Assessment, Health Care; D014374:Tuberculin Test; D014376:Tuberculosis / Q000517:prevention & control*
chemical_list: D001500:BCG Vaccine
keywords: child; interferon-γ release assay; latent tuberculosis infection; tuberculin skin test