Table 6. Diagnostic potential of individual markers detected in QFT-IT supernatants.
| Markers | TB cases (n = ) | Non TB cases (n = ) | P-value | AUC (95% CI) | Sensitivity, % (95% CI) | Specificity, % (95% CI) | Cut off value |
| VEGF Ag | 100 (2–290) | 120 (2–352) | 0.085 | 67 (47–87) | 79 (49–95) | 60 (32–84) | 117.0 |
| CRPAg | 188210 (3411–816000) | 12918 (120–332914) | 0.009 | 80 (62–95) | 64 (49–95) | 87 (27–78) | 72307.0 |
| SAAAg | 579939 (560–4000000) | 1115 (560–222320) | 0.004 | 82 (66–98) | 79 (49–95) | 73 (45–92) | 22752.0 |
| SAPAg | 48247 (24799–74998) | 35242 (560–69282) | 0.034 | 73 (54–93) | 79 (49–95) | 80 (52–96) | 41205.0 |
| MMP-9Ag | 738806 (354239–700362629) | 1435154 (278743–2444144) | 0.073 | 72 (49–95) | 71 (42–92) | 67 (30–93) | 935846.0 |
| IP-10Ag-Nil | 15799 (0–19426) | 1773 (0–16430) | 0.007 | 80 (65–97) | 64 (57–98) | 93 (32–84) | 15696.0 |
| MCP-1Ag-Nil | 388 (0–7881) | 0 (0–12922) | 0.047 | 73 (52–91) | 79 (49–95) | 67 (38–88) | –732.0 |
| MCP-1Nil | 9969 (1909–18125) | 14912 (4368–20001) | 0.015 | 77 (59–94) | 60 (66–100) | 93 (32–84) | 14651.0 |
| MIP-1β Nil | 1096 (74–2258) | 1792 (548–3190) | 0.017 | 76 (59–93) | 73 (42–92) | 64 (32–84) | 1334.0 |
| TGF-α Nil | 8 (2–39) | 30 (2–144) | 0.047 | 70 (50–90) | 86 (57–98) | 60 (32–83) | 24.0 |
| VEGF Nil | 31 (2–626) | 285 (2–727) | 0.041 | 73 (51–91) | 60 (49–95) | 79 (32–84) | 216.0 |
| IL-10 Nil | 8 (2–51) | 41 (2–86) | 0.032 | 74 (55–92) | 80 (35–87) | 64 (52–96) | 11.0 |
| IL-1β Nil | 108 (2–365) | 331 (17–1957) | 0.050 | 72 (53–90) | 67 (35–87) | 84 (38–88) | 254.0 |
| CRP Nil | 457028 (2831–816000) | 35080 (157–816000) | 0.032 | 78 (55–92) | 64 (42–91) | 80 (32–84) | 66232.0 |
| SAA Nil | 1979000 (943–4160000) | 1821 (560–173709) | 0.002 | 84 (70–99) | 64 (49–95) | 100 (38–88) | 176199.0 |
| SAP Nil | 44639 (23918–56777) | 32733 (22470–79572.) | 0.026 | 76 (55–94) | 79 (49–95) | 73 (45–92) | 38751.0 |
| MMP-9 Nil | 617975 (275049–720100) | 1347000 (331645–360500) | 0.018 | 83 (60–100) | 89 (49–95) | 79 (51–100) | 766037.0 |
Median levels (and ranges in parenthesis) of analytes detected in QFT-IT supernatants and accuracy in the diagnosis of TB disease. All analyte levels are in pg/ml except for CRP, SAA and SAP (ng/ml). P-values were calculated using the Mann Whitney U test. Cut-off values, sensitivity and specificity were selected based on the Youden’s index. AUC = Area under the receiver operator characteristics curve. 95% CI = 95% confidence interval. Nil = unstimulated marker levels, Ag = levels detected in antigen stimulated supernatants, Ag-N = Antigen specific marker levels obtained after subtraction of nil responses.