IFNG and tuberculosis: Median IFN-γ responses differed significantly in Xpert MTB/RIF-positive (130/480) vs. Xpert MTB/RIF-negative (350/480) individuals when measured using the TSPOT.TB [109 (IQR: 49–206) vs. 40 (10–115) SFC⋅10−6 PBMCs; p<0.01] and QFT-GIT assays [2.2 (0.6–5.4) vs. 0.7 (0.1–3.1) IU⋅ml−1; p<0.01], but not in response to PPD [100 (45–160) vs. 91 (17–185) SFC⋅10−6 PBMCs; p = 0.21].