Given the low specificity of the PPD IFN-γ test and the low sensitivity of the ESAT-6 IFN-γ test for the detection of LTBI in this population, we assessed the diagnostic value of HBHA, a novel antigen, previously shown to induce significantly higher IFN-γ production by PBMC from LTBI compared to controls and TB patients [20], [21]. This evidence concerns the gene IFNG and tuberculosis.