IFNG and tuberculosis: In contrast, average Ag85-specific IFN-γ response in asymptomatic tuberculin-positive subjects was not significantly different in the group of HIV-negative and HIV-positive subjects (although there was a tendency to decrease) but interestingly a follow-up analysis of these Ag85-specific IFN-γ responses in five tuberculin-positive subjects classified as CDC-A according to CDC classification [32] over a period of one year indicated that decreased reactivity against Ag85 in three of them coincided with reactivation and development of clinical tuberculosis.