Table 4.
Diagnostic performance of candidate markers in distinguishing CKDu, ECKD, and NECKD from NEC
| Parameter | AUC (95% CI) | % (95% CI) |
P value | |
|---|---|---|---|---|
| Sensitivity | Specificity | |||
| CKDu vs. NEC | ||||
| A1M | 0.914 (0.863–0.966) | 92.0 (83.2–96.5) | 84.7 (75.4–90.9) | <0.0001 |
| B2M | 0.696 (0.604–0.787) | 53.3 (42.2–64.2) | 92.9 (85.1–97.0) | <0.0001 |
| CST3 | 0.817 (0.749–0.885) | 69.3 (58.1–78.6) | 84.7 (75.4–90.9) | <0.0001 |
| NGAL | 0.827 (0.759–0.894) | 82.7 (72.4–89.7) | 72.9 (62.6–81.2) | <0.0001 |
| OPN | 0.585 (0.486–0.684) | 44.0 (33.3–55.3) | 84.7 (75.4–90.9) | 0.093 |
| RBP4 | 0.735 (0.650–0.819) | 81.3 (70.9–88.6) | 63.5 (52.9–73.0) | <0.0001 |
| KIM1 | 0.520 (0.422–0.617) | 38.7 (28.5–50.0) | 72.9 (62.6–81.2) | 0.694 |
| TIMP1 | 0.620 (0.527–0.713) | 40.0 (29.7–51.3) | 84.7 (75.4–90.9) | 0.011 |
| ECKD vs. NEC | ||||
| A1M | 0.913 (0.867–0.959) | 87.8 (78.7–93.4) | 84.7 (75.4–90.9) | <0.0001 |
| B2M | 0.832 (0.763–0.901) | 74.4 (63.9–82.6) | 89.4 (80.8–94.5) | <0.0001 |
| CST3 | 0.843 (0.779–0.906) | 72.0 (61.3–80.5) | 90.6 (82.2–95.3) | <0.0001 |
| NGAL | 0.797 (0.728–0.865) | 75.6 (65.2–83.6) | 75.3 (65.1–83.3) | <0.0001 |
| OPN | 0.756 (0.681–0.832) | 48.8 (38.3–59.4) | 95.3 (88.0–98.5) | <0.0001 |
| RBP4 | 0.804 (0.731–0.877) | 85.4 (75.9–91.5) | 74.1 (63.8–82.3) | <0.0001 |
| KIM1 | 0.684 (0.602–0.766) | 80.5 (70.5–87.7) | 50.6 (40.2–60.9) | <0.0001 |
| TIMP1 | 0.738 (0.664–0.813) | 54.9 (44.1–65.2) | 84.7 (75.4–90.9) | <0.0001 |
| NECKD vs. NEC | ||||
| A1M | 0.891 (0.843–0.938) | 77.6 (67.6–85.2) | 91.8 (83.6–96.2) | <0.0001 |
| B2M | 0.852 (0.795–0.909) | 77.6 (67.6–85.2) | 82.4 (72.7–89.1) | <0.0001 |
| CST3 | 0.851 (0.791–0.910) | 70.6 (60.1–79.2) | 90.6 (82.2–95.3) | <0.0001 |
| NGAL | 0.767 (0.697–0.837) | 69.4 (58.9–78.2) | 75.3 (65.1–83.3) | <0.0001 |
| OPN | 0.586 (0.499–0.674) | 54.1 (43.6–64.3) | 69.4 (58.9–78.2) | 0.053 |
| RBP4 | 0.862 (0.805–0.919) | 91.8 (83.6–96.2) | 76.5 (66.3–84.2) | <0.0001 |
| KIM1 | 0.716 (0.639–0.792) | 78.8 (68.9–86.2) | 55.3 (44.7–65.4) | <0.0001 |
| TIMP1 | 0.747 (0.674–0.820) | 55.3 (44.7–65.4) | 84.7 (75.4–90.9) | <0.0001 |
A1M, alpha 1 microglobulin; AUC, area under the curve; B2M, beta 2 microglobulin; CI, confidence interval; CKDu, chronic kidney disease of uncertain etiology; CST3, cystatin C; ECKD, endemic chronic kidney disease; KIM1, kidney injury molecule 1; NEC, nonendemic control; NECKD, nonendemic chronic kidney disease; NGAL, neutrophil gelatinase-associated lipocalin; OPN, osteopontin; RBP4, retinol binding protein 4; TIMP1, tissue inhibitor of metalloproteinase 1.