Table 4: Utility of host markers detected in serum in the diagnosis of TB disease.

MarkerTB casesNon-TB cases valueAUC (95% CI)Cut-off valueSensitivity % (95% CI)Specificity % (95% CI)

IL-6 11.5 (0.0–28.1)0.0 (0.0-0.0)0.010.73 (0.54–0.92)>27.5427.3 (6.0–61.0)96.3 (81.0–99.9)
IL-2 0.6 (0.0–1.3)0.0 (0.0-0.0)0.010.73 (0.53–0.92)>0.9545.5 (16.8–76.6)92.6 (75.7–99.1)
SAP 60894.8 (45137.4–65623.2)42251.4 (36985.9–53804.8)0.030.72 (0.54–0.90)>5891454.6 (23.4–83.3)85.2 (66.3–95.8)
SAA 239.1 (0.0–848.8)6133.8 (2012.1–40070.2)0.050.70 (0.52–0.88)>94189418.2 (2.3–51.8)96.3 (81.0–99.9)

Median levels (pg/mL) and interquartile ranges (in parenthesis) of the markers and abilities to discriminate between pulmonary TB cases ( ) and individuals without active TB ( ) are shown. Only markers for which Mann-Whitney    values were ≤0.09 are shown. AUC: area under the receiver operator characteristics (ROC) curve; 95% CI: 95% confidence interval. The cut-off values are for sensitivity and specificity for TB disease and were selected based on the highest likelihood ratio. Marker levels are in pg/mL except for SAA and SAP (ng/mL).