CD4 and tuberculosis: Following this observation, we performed a ROC analysis (Figure 2(a)) and a cut-off >0.45% for activated CD4+ T cells was found as the value allowing the best combination of sensitivity (94.44%, 95% CI: 72.2–99.8%) and specificity (100%, 95% CI: 69.15–100%; AUC 0.9722; 95% CI: 0.9141–1.030%, P < 0.0001) to differentiate Mtb-infected patients (active TB and LTBI) from healthy controls.