Table 4.
Diagnostic accuracy of individual serum and pleural fluid tests for distinguishing CPPE and empyema from UPPE
| Cutoff | Sensitivity (%) | Specificity (%) | LR+ | LR- | AUC (95% confidence interval) | |
|---|---|---|---|---|---|---|
| Serum | ||||||
| NGAL (ng/ml) | > 220 ng/ml | 68.4 | 77.5 | 3.04 | 0.41 | 0.775 (0.672–0.878) |
| Calprotectin (μg/ml) | > 6 μg/ml | 65.8 | 77.5 | 2.92 | 0.44 | 0.765 (0.661–0.870) |
| CRP (mg/dl) | > 12.5 mg/dl | 85.3 | 69.4 | 2.79 | 0.21 | 0.766 (0.651–0.881) |
| IL-6 (pg/ml) | > 31 pg/ml | 82.9 | 55.3 | 1.85 | 0.31 | 0.717 (0.601–0.833) |
| Pleural effusion | ||||||
| NGAL (ng/ml) | > 600 ng/ml | 78.9 | 85.0 | 5.26 | 0.25 | 0.855 (0.770–0.941) |
| Calprotectin (μg/ml) | > 90 μg/ml | 84.2 | 97.5 | 33.68 | 0.16 | 0.965 (0.929–1.000) |
| BPI (ng/ml) | > 10 ng/ml | 97.4 | 87.5 | 7.79 | 0.03 | 0.970 (0.940–1.000) |
| AZU1 (ng/ml) | > 175 ng/ml | 97.4 | 57.5 | 2.29 | 0.05 | 0.860 (0.781–0.939) |
| CRP (mg/dl) | > 7.3 mg/dl | 84.2 | 87.2 | 6.58 | 0.18 | 0.879 (0.800–0.957) |
| IL-6 (ng/ml) | > 31 ng/ml | 81.6 | 72.5 | 2.97 | 0.25 | 0.818 (0.719–0.918) |
LR+ Positive likelihood ratio, LR- Negative likelihood ratio, AUC Area under the ROC curve, NGAL Neutrophil gelatinase-associated lipocalin, BPI Bactericidal permeability-increasing protein, AZU1 Azurocidin, CRP C-reactive protein