High level of discordant IGRA results in HIV-infected adults and children

Int J Tuberc Lung Dis. 2008 Apr;12(4):417-23.


Setting: Tygerberg district, Western Cape Province, South Africa.

Objective: To measure the agreement of two interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST) for the detection of Mycobacterium tuberculosis infection in human immunodeficiency virus (HIV) infected adults and children in a setting highly endemic for tuberculosis (TB).

Design: Cross-sectional study.

Results: In HIV-infected adults (n=20) and children (n=23), tests yielded discordant results, with 61% of individuals testing positive with T-SPOT.TB, 41% with TST and 28% with QuantiFERON TB Gold (QTF). In children, there was poor agreement between the TST and T-SPOT.TB (kappa [kappa]=-0.02), but moderate agreement between the TST and QTF (kappa=0.44). In adults, there was moderate agreement between the TST and T-SPOT.TB (kappa=0.43), and the TST and QTF (kappa = 0.46). In children and adults, there was fair agreement between the T-SPOT.TB and QTF (kappa=0.33). Twenty per cent of adults had >or=1 indeterminate IGRA results.

Conclusions: There is poor to moderate agreement between the TST and IGRAs in HIV-infected adults and children. T-SPOT.TB may have improved sensitivity for detection of M. tuberculosis infection in HIV-infected individuals compared to the QTF and the TST. In HIV-infected individuals, IGRA test properties are affected by test cut-off point and nil control responses.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIDS-Related Opportunistic Infections / diagnosis*
  • Antigens, Bacterial
  • Bacterial Proteins
  • Cross-Sectional Studies
  • HIV Infections / complications
  • Humans
  • Immunologic Tests*
  • Interferon-gamma / blood*
  • Mycobacterium tuberculosis / isolation & purification*
  • Sensitivity and Specificity
  • South Africa / epidemiology
  • Tuberculin Test
  • Tuberculosis / complications
  • Tuberculosis / diagnosis*
  • Tuberculosis / epidemiology


  • Antigens, Bacterial
  • Bacterial Proteins
  • CFP-10 protein, Mycobacterium tuberculosis
  • ESAT-6 protein, Mycobacterium tuberculosis
  • Interferon-gamma