IFNG and tuberculosis: Variables that did not associate with TB disease risk included D0 purified protein derivative (PPD) IFN-γ ELISpot (estimated OR=0.72, P=0.453) and D28 Ag85A peptide IFN-γ ELISpot (estimated OR=0.69, P=0.183) and the D0 MGIA (estimated OR=0.31, P=0.318; Table 1).