In vitro QuantiFERON-TB gold antigen specific interleukin-1beta to diagnose TB among HIV-positive subjects

The TB antigen specific IL-1β levels were significantly elevated in HIV-TB co-infected patients compared to HIV positive subjects (p = 0.0004). The specificity of both IL-1β (50.94%) and QFT-GIT (52.83%) remained similar in HIV positive subjects (p = 0.24). However, IL-1β had shown higher sensitivity (72.73%) than QFT-GIT (54.55%) to diagnose TB among HIV co-infected patients. Moreover, in culture test positive HIV-TB patients, antigen specific IL-1β exhibited sensitivity of 84.21%; whereas QFT-GIT exhibited only 57.89% sensitivity. Unlike IFN-γ (the read out marker of QFT-GIT), antigen specific IL-1β levels were not influenced by low CD4 counts. The other cytokine levels were not significantly differ between the 2 groups.From this study we concluded that TB antigen specific IL-1β may be an additional biomarker for active TB diagnosis among HIV positive subjects.