title: IGRA as a predictive factor of silent pulmonary changes in individuals following exposure to tuberculosis.
abstract: OBJECTIVE
  We conducted a study on usefulness of the tuberculin skin test (TST) and the Quantiferon-TB Gold IT (QFT) tests as predictors of radiological changes after contact with tuberculosis.
  
  
  METHODS
  The study group consisted of TB-exposed HCWs working in the Military Institute of Medicine (Warsaw, Poland). The usefulness of TST, QFT, and a combination of both tests was assessed for prediction of silent radiological findings.
  
  
  RESULTS
  83 previously TB-exposed participants were recruited. None of the participants had a history of active tuberculosis. Positive TST results were reported in 72 (86.8 %) participants, and positive QFTs were observed in 27 (32.5 %) cases. Chest radiographs revealed 23 findings specific for non-active tuberculosis in 18 (21.7 %) participants. The results of the QFTs were associated with the highest negative predictive value, positive predictive value, and positive likelihood ratio of silent chest X-ray findings suggestive of latent tuberculosis infection. Positive QFT was the only statistically significant variable that increases the odds ratio (OR-8.3) of the presence of typical of tuberculosis radiological changes in the lung.
  
  
  CONCLUSIONS
  A positive QFT result in an individual with no TB history who was exposed to tuberculosis in the past is associated with a significantly higher risk of clinically silent parenchymal lesions in lungs suggestive of previous tuberculosis.
authors.affiliation: Department of Internal Medicine, Pneumonology and Allergology, Military Institute of Medicine, Ul. Szaserów 128, 04-141, Warsaw, Poland, targowski.tomasz_xl@wp.pl.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Targowski
authors.forename: Sylwia
authors.initials: S
authors.lastname: Chelstowska
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Plusa
mesh_terms: D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001681:Biological Assay; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D007371:Interferon-gamma / Q000097:blood*; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000635:transmission*; D016015:Logistic Models; D008168:Lung / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011044:Poland; D011237:Predictive Value of Tests; D011859:Radiography; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012737:Sex Factors; D014374:Tuberculin Test / Q000379:methods*
chemical_list: D015415:Biomarkers; D007371:Interferon-gamma