IFNG and tuberculosis: In our cohort, IFN-γ producing cells were not compromised by active TB disease or age (or time of Mtb exposure), since blood cells of all groups were similarly effective in secreting IFN-γ in response to antigens present in the QuantiFERON-TB Gold test [ESAT-6/CFP-10/TB-7.7(p4)] (Table 1) and to other specific Mtb antigens (Figure 1).