title: The performance of quantiferon-TB gold in-tube (QFT-IT) test compared to tuberculin skin test (TST) in detecting latent tuberculosis infection (LTBI) in the presence of HIV coinfection in a high TB-burden area with BCG-vaccinated population.
abstract: OBJECTIVE
  To compare quantiferon-TB gold "in tube" (QFT-IT) with the conventional tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI) in HIV-infected adults in a setting highly endemic for tuberculosis with BCG vaccinated population in Bangalore, Karnataka, India.
  
  
  METHODS
  The study population (100 BCG-vaccinated adults) was divided into 4 groups: HIV patients with TB patient contact, HIV patients with past history of TB, TB patients (positive control), and healthy volunteers (negative control).
  
  
  RESULTS
  Overall agreement between TST and QFT-IT was 52.4% (κ = 0.22). Increasing the TST cutoff value from 5 mm to 10 mm among HIV-positive groups resulted in better agreement 62.5% in Group 1 and 81.2% in Group 2.
  
  
  CONCLUSIONS
  In a setting with high TB prevalence, the TST gives increased false positives in HIV-positive groups if 5 mm is used as the cutoff value. This could be minimized by increasing the cutoff to 10 mm.
  
  
  CONCLUSIONS
  The 2-step approach (initial testing of all cases with TST and confirmation of only those positive in TST by testing with QFT-IT) will be economical and help in treating LTBI cases in lower middle income countries like India.
authors.affiliation: Kempegowda Institute of Medical Sciences, Bangalore, India.
authors.forename: Pratibha Malini
authors.initials: PM
authors.lastname: James
authors.forename: Feroze Ahmed
authors.initials: FA
authors.lastname: Ganaie
authors.forename: Ravikumar Lingegowda
authors.initials: RL
authors.lastname: Kadahalli
mesh_terms: D000328:Adult; D001500:BCG Vaccine / Q000008:administration & dosage*; D016022:Case-Control Studies; D060085:Coinfection / Q000175:diagnosis; D005260:Female; D015658:HIV Infections / Q000378:metabolism*; D006801:Humans; D007194:India; D059425:Interferon-gamma Release Tests; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000821:virology*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014374:Tuberculin Test
chemical_list: D001500:BCG Vaccine
keywords: HIV infection; QuantiFERON-IT; interferon gamma release assay; latent tuberculosis infection; tuberculin skin test