Interferon γ in patients with HIV/AIDS and suspicion or latent tuberculosis infection

Objective: To assess the usefulness of IGRA test (QuantiFERON (R) -Cell mediated immune) compared with the tuberculin skin test. Methods: A cross sectional study was carried out in Mexico, 25 infected patients with HIV-AIDS and the suspicion or with latent tuberculous infection (LTBI) who were >18 years of age and without treatment for tuberculosis (TB), were enrolled in the study. Results: Median cluster of differentiation (CD4) count was 364 cells/ mu L and median HIV viral load was 50 copies/mL. Overall, 20 patients (80%) had at least one positive diagnostic test for LTBI: four (16%) had a positive tuberculin skin test and 19 (76%), a positive QuantiFERON (R) -tuberculosis. Conclusions: No agreement is found between the two diagnostic tests: k = -0.004, 95% confidence interval (-0.2219, 0.2210). Additional longitudinal studies among HIV-infected populations with high prevalence of TB are needed to further assess the usefulness of IGRAs in this patient population.