title: [Interferon-gamma assays T-SPOT.TB for the diagnosis of latent tuberculosis infection].
abstract: BACKGROUND
  The diagnosis of latent tuberculosis infection (LTBI) is currently based on the century-old tuberculin skin test (TST). However a positive reaction can result from infection by Mycobacterium tuberculosis, BCG vaccination or cross-reaction with nontuberculous mycobacteria. T-SPOT.TB assay is a new test to diagnose tuberculosis infection by measuring in vitro T-cell interferon gamma release in response to two Mycobacterium tuberculosis-specific antigens: ESAT-6 and CFP 10.
  
  
  METHODS
  T-SPOT.TB assay has been performed on whole blood samples (n = 137) from March to September 2010. A tuberculin skin test result was available for 96 of participants. A positive TST result was considered if the induration was 10 mm or more.
  
  
  RESULTS
  Of the 137 patients tested, T-SPOT.TB assay results were positive in 37 (27%), negative in 98 (71.5%) and indeterminate in only 2 (1.5%) persons. We analyzed T-SPOT.TB and TST results in the 96 patients for whom both test were available. Concordance between T-SPOT.TB and TST results (10 mm skin reaction interpreted as positive) was 79%. Fifteen (15.6%) patients had a positive TST result and a negative T-SPOT.TB and 5 (5.2%) patients had a negative TST result and a positive T-SPOT.TB. We observed good correlation between positive T-SPOT.TB results and the size of induration ≥ 15 mm in TST results.
  
  
  CONCLUSIONS
  T-SPOT.TB offers a more accurate approach than TST for identification tuberculosis infection. The study shows that the test T-SPOT.TB is a good diagnostic tool in identifying persons with tuberculosis infection. For full confirmation of this assessment, it is necessary to examine more cases.
authors.affiliation: Zakład Mikrobiologii, Instytut Gruźlicy i Chorób Płuc w Warszawie Kierownik, ul. Płocka 26, Warsaw.
authors.forename: Dagmara
authors.initials: D
authors.lastname: Borkowska
authors.forename: Zofia
authors.initials: Z
authors.lastname: Zwolska
authors.forename: Dorota
authors.initials: D
authors.lastname: Michałowska-Mitczuk
authors.forename: Maria
authors.initials: M
authors.lastname: Korzeniewska-Koseła
authors.forename: Anna
authors.initials: A
authors.lastname: Zabost
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Napiórkowska
authors.forename: Monika
authors.initials: M
authors.lastname: Kozińska
authors.forename: Sylwia
authors.initials: S
authors.lastname: Brzezińska
authors.forename: Ewa
authors.initials: E
authors.lastname: Augustynowicz-Kopeć
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D055985:Latent Tuberculosis / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D014374:Tuberculin Test
chemical_list: D007371:Interferon-gamma