CD4 and tuberculosis: Moreover, HLA-DR expression on Mtb-specific CD4 T cells also discriminated LTBI from PCTB (P < .0001; AUC = 0.94 [95% CI, .82–1.00]; sensitivity: 93.75%, specificity: 100%, at an optimal cutoff of 46.9%) and LTBI from any active TB (P < .0001; AUC = 0.96 [95% CI, .90–1.00]; sensitivity: 94.29%, specificity: 100%, at an optimal cutoff of 46.9%) (Supplementary Figure 6A and 6B).