title: [Analysis of discordance between tuberculin test and QuantiFERON-TB® Gold In-Tube in studies of contacts].
abstract: OBJECTIVE
  Our objective is to compare the tuberculin skin test (TST) and the QuantiFERON-TB(®) Gold In-Tube (QFT) in the diagnosis of latent tuberculosis infection (LTI) in a population of contacts of patients with pulmonary tuberculosis, and to analyze the influence of different variables in the discordance.
  
  
  METHODS
  From March 2008 to September 2010, among a population of 300,000 inhabitants of the Basque Country, we analyzed all contacts of patients with pulmonary tuberculosis. All patients underwent the TST and the value of QFT was measured. Sociodemographic variables and vaccination were examined and we analyzed the discordance between the 2 tests.
  
  
  RESULTS
  Seven hundred and four were included in the study, with a mean age of 27 years. Of these, 397 were vaccinated, with similar proportion between native and foreign. Increasing the age to 59 years (odds ratio [OR] 10.53, P<.001), being foreign (OR 2.71, P=.02) and vaccination (OR 4.22, P<.001) were predictors of the discordance between a positive TST and negative QFT.
  
  
  CONCLUSIONS
  It seems that the QFT, alone or combined with the TST, is a safe method for the diagnosis of LTI and its use would contribute to a more specific selection of individuals who would need preventive treatment.
authors: Servicio de Neumología, Hospital de Galdakao, Galdakao, Vizcaya, Spain. aitor.ballazquincoces@yahoo.es.net
authors: Aitor
authors: A
authors: Ballaz
authors: Carlos
authors: C
authors: Salinas
authors: Urko
authors: U
authors: Aguirre
authors: Maria José
authors: MJ
authors: López de Goicoechea
authors: Rosa
authors: R
authors: Diez
authors: Mikel
authors: M
authors: Egurrola
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D016358:Contact Tracing; D005260:Female; D006801:Humans; D007223:Infant; D059425:Interferon-gamma Release Tests; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000517:prevention & control / Q000635:transmission; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D013030:Spain; D014374:Tuberculin Test; D014611:Vaccination / Q000706:statistics & numerical data; D055815:Young Adult