Table 4.
Diagnostic characteristics of synovial fluid biomarkers
| Biomarker | AUC | Cutoff | Specificity (%) | 95% CI (%) | Sensitivity (%) | 95% CI (%) |
|---|---|---|---|---|---|---|
| α-Defensin | 1.000 | 4.8 μg/mL | 100 | 95–100 | 100 | 88–100 |
| ELA-2 | 1.000 | 2.0 μg/mL | 100 | 95–100 | 100 | 88–100 |
| BPI | 1.000 | 2.2 μg/mL | 100 | 95–100 | 100 | 88–100 |
| NGAL | 1.000 | 2.2 μg/mL | 100 | 95–100 | 100 | 88–100 |
| Lactoferrin | 1.000 | 7.5 μg/mL | 100 | 95–100 | 100 | 88–100 |
| IL-8 | 0.992 | 6.5 ng/mL | 95 | 87–99 | 100 | 87–100 |
| SF CRP | 0.987 | 12.2 mg/L | 97 | 90–100 | 90 | 73–98 |
| Resistin | 0.983 | 340 ng/mL | 100 | 95–100 | 97 | 82–99 |
| Thrombospondin | 0.974 | 1061 ng/mL | 97 | 90–100 | 90 | 73–98 |
| IL-1β | 0.966 | 3.1 pg/mL | 95 | 87–99 | 96 | 82–100 |
| IL-6 | 0.950 | 2.3 ng/mL | 97 | 89–100 | 89 | 71–98 |
| IL-10 | 0.930 | 32.0 pg/mL | 89 | 79–96 | 89 | 72–98 |
| IL-1α | 0.922 | 4.0 pg/mL | 91 | 81–97 | 82 | 63–94 |
| IL-17 | 0.892 | 3.1 pg/mL | 99 | 92–100 | 82 | 63–94 |
| G-CSF | 0.859 | 15.4 pg/mL | 92. | 82–97 | 82 | 62–94 |
| VEGF | 0.850 | 2.3 ng/mL | 77 | 65–87 | 75 | 55–89 |
AUC = area under the curve; α-defensin = human α-defensin 1-3; ELA-2 = neutrophil elastase 2; BPI = bactericidal/permeability-increasing protein; NGAL = neutrophil gelatinase-associated lipocalin; SF = synovial fluid; CRP = C-reactive protein; G-CSF = granulocyte colony-stimulating factor; VEGF = vascular endothelial growth factor.