IFNG and tuberculosis: However, in the HIV/TB-coinfected patients, we observed a positive correlation between the plasma levels of IL-15 and IL-17 (r = 0.377, p = 0.024; Figure 3A) and a negative correlation between the plasma levels of IFN-γ and IL-18 (r = −0.486, p = 0.048; Figure 3B).