Latent tuberculosis detection by interferon γ release assay during pregnancy predicts active tuberculosis and mortality in human immunodeficiency virus type 1-infected women and their children

Abstract

Background: We evaluated the prognostic usefulness of interferon γ release assays (IGRAs) for active tuberculosis and mortality in Kenyan human immunodeficiency virus type 1 (HIV-1)-infected women and their infants. Methods: Prevalence and correlates of Mycobacterium tuberculosis-specific T-SPOT.TB IGRA positivity were determined during pregnancy in a historical cohort of HIV-1-infected women. Hazard ratios, adjusted for baseline maternal CD4 cell count (aHRCD4), were calculated for associations between IGRA positivity and risk of active tuberculosis and mortality over 2-year postpartum follow-up among women and their infants. Results: Of 333 women tested, 52 (15.6%) had indeterminate IGRA results. Of the remaining 281 women, 120 (42.7%) had positive IGRA results, which were associated with a 4.5-fold increased risk of active tuberculosis (aHRCD4, 4.5; 95% confidence interval [CI], 1.1-18.0; P=.030). For immunosuppressed women (CD4 cell count, <250 cells/μL), positive IGRA results were associated with increased risk of maternal mortality (aHRCD4, 3.5; 95% CI, 1.02-12.1; ), maternal active tuberculosis or mortality (aHRCD4P=.045, 5.2; 95% CI, 1.7-15.6; P=.004), and infant active tuberculosis or mortality overall (aHR CD4, 3.0; 95% CI, 1.0-8.9; P=.05) and among HIV-1-exposed uninfected infants (aHRCD4, 7.3; 95% CI, 1.6-33.5; P=.01). Conclusions: Positive IGRA results for HIV-1-infected pregnant women were associated with postpartum active tuberculosis and mortality among mothers and their infants. © 2010 by the Infectious Diseases Society of America. All rights reserved.