Based on these differences, we performed a ROC analysis (Figure 4(a)) and cut-off < 0.182% for polyfunctional CD4+ T cells allowed the best combination of sensitivity (77.78%, 95% CI: 52.36–93.59) and specificity (70%, 95% CI: 34.75–93.33%; AUC 0.8444; 95% CI: 0.7021–0.9868%, P = 0.0002) to differentiate between active TB and LTBI subjects. Here, CD4 is linked to tuberculosis.