Relationship of immunodiagnostic assays for tuberculosis and numbers of circulating CD4+ T-cells in HIV infection

Infection with HIV is the greatest risk factor for tuberculosis (TB) in Africa. Tuberculin skin test (TST), QuantiFERON-TB Gold In-Tube (QFT-G-IT) and T-Spot.TB assays were performed in newly diagnosed HIV-infected individuals with and without active TB and in HIV-uninfected subjects at a university outpatient clinic in Kampala, Uganda. A total of 135 individuals were enrolled: 109 with a new diagnosis of HIV-1 infection but no active TB, 19 with HIV-1 infection and active TB, and seven HIV-uninfected healthy subjects. In control subjects immune responses were positive in 57.2% by TST and in 100% by at least one interferon-gamma release assay. In HIV-1 infected patients without active TB, induration in the TST (mm) (rho = 0.41, p-value