Predictive value for progression to tuberculosis by IGRA and TST in immigrant contacts

Eur Respir J. 2010 Jun;35(6):1346-53. doi: 10.1183/09031936.00098509. Epub 2009 Oct 19.

Abstract

The authors determined the positive predictive value (PPV) for progression to tuberculosis (TB) of two interferon-gamma release assays (IGRAs), QuantiFERON-TB Gold In-tube (QFT-GIT) and T-SPOT.TB, and the tuberculin skin test (TST) in immigrants contacts. Immigrant close contacts of sputum smear-positive TB patients were included when aged > or =16 yrs and their TST result was > or =5 mm 0 or 3 months after diagnosis of the index patient. Contacts were followed for the next 2 yrs for development of TB disease. Of 339 immigrant contacts with TST > or =5 mm, 324 and 299 had valid results of QFT-GIT and T-SPOT.TB, respectively. Nine contacts developed active TB. One patient had not been tested with TST, while another patient had not been tested with QFT-GIT and T-SPOT.TB. The PPV for progression to TB during this period was 9/288 = 3.1% (95% CI 1.3-5.0%) for TST > or =10 mm, 7/184 = 3.8% (95% CI 1.7-5.9%) for TST > or =15 mm, 5/178 = 2.8% (95% CI 1.0-4.6%) for QFT-GIT and 6/181 = 3.3% (95% CI 1.3-5.3%) for T-SPOT.TB. Sensitivity was 100%, 88%, 63% and 75%, respectively. The predictive values of QFT-GIT, T-SPOT.TB and TST for progression to TB disease among immigrant close contacts were comparable.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Contact Tracing / methods*
  • Contact Tracing / statistics & numerical data*
  • Emigrants and Immigrants / statistics & numerical data*
  • Enzyme-Linked Immunosorbent Assay
  • Follow-Up Studies
  • Humans
  • Incidence
  • Interferon-gamma / metabolism*
  • Netherlands / epidemiology
  • Predictive Value of Tests
  • Prospective Studies
  • Reagent Kits, Diagnostic
  • Risk Factors
  • Tuberculin Test*
  • Tuberculosis, Pulmonary* / diagnosis
  • Tuberculosis, Pulmonary* / epidemiology
  • Tuberculosis, Pulmonary* / transmission
  • Young Adult

Substances

  • Reagent Kits, Diagnostic
  • Interferon-gamma