Table 2.
Performance of BAL cytokines as diagnostic biomarkers for IPA.
| Cytokine | Cut-off† | Sensitivity | Specificity | PPV | NPV | NRI |
|---|---|---|---|---|---|---|
| (95% CI) | ||||||
| IL-1β | 27.1 | 70 (55–83) | 68 (55–81) | 70 (60–79) | 69 (58–78) | 0.34 |
| IL-6 | 89.8 | 74 (63–85) | 79 (68–89) | 78 (67–87) | 73 (63–81) | 0.51 |
| IL-8 | 904 | 90 (81–98) | 73 (60–85) | 78 (68–85) | 88 (75–94) | 0.63 |
| IL-17A | 0.66 | 72 (58–84) | 81 (70–90) | 80 (68–88) | 74 (64–82) | 0.53 |
| IL-23 | 103 | 76 (66–90) | 77 (67–90) | 78 (67–86) | 76 (65–84) | 0.53 |
| TNF-α | 0.94 | 80 (70–90) | 69 (55–81) | 73 (63–81) | 77 (65–86) | 0.49 |
†
Cut-off values of cytokines are expressed as pg/mL. Statistically-derived optimal cut-off was determined by Youden's index (maximum sensitivity and specificity given by the inflection point of the AUCROC). The net reclassification index (NRI) was used to compare the performance of each cytokine cut-off with the known diagnosis of IPA. IL, interleukin; TNF, tumor necrosis factor; PPV, positive predictive value; NPV, negative predictive value.