IFNG and tuberculosis: In all three groups, there were significantly higher levels of IP-10 than of IFN-γ following antigen stimulation (Control - IFNγ median 7.25 pg/ml, range 3.5–46.5 pg/ml; IP-10 median 536 pg/ml, range: 320–40,000 pg/ml:p = 0.0001; LTBI - IFNγ median 2205 pg/ml, range 60–31084 pg/ml; IP-10 median 19350 pg/ml, range 2,200–40,000 pg/ml, p = 0.0047: Active TB - median IFNγ 1124.5 pg/ml, range 10–11928.5 pg/ml; IP-10 median 9544 pg/ml, range 1386–40,000 pg/ml, p = 0.0011: (Figure 2).