IFNG and pulmonary tuberculosis: In order to determine the predictive power of Th1 and Th2 in discriminating Pulmonary Tuberculosis status (PTB) (culture status was used as a confirmatory test), binary logistic regression models were fitted for Th1 covariates [IFN-γ, TNF-α, IL-2 and IL-12(p70)] and Receiver Operating Characteristic (ROC) curves plotted.