Table 3.
Numbers of MCP-1-, NGAL-, and OPN-associated urinary extracellular vesicles from the different segmental epithelium of nephrons in nonstone formers (controls) and idiopathic calcium stone formers
| Segment of the Nephron | Nephron Segmental Epithelium Marker |
Tested Combination Biomarker | Nonstone Formers (n = 40) | Calcium Stone Formers | P Value |
|---|---|---|---|---|---|
| Proximal tubule | URAT1 | MCP-1 | 13.2 (3.4, 44.9) | 4.6 (1, 21.1) | 0.05* |
| Ascending thin limb | Aquaporin-1 | MCP-1 | 29.2 (7.6, 96.3) | 5 (0.2, 26) | <0.01* |
| Thick limb | Uromodulin | MCP-1 | 3.7 (1.5, 19.7) | 3.4 (1, 12.2) | 0.40 |
| Distal tubule | SLC12A3 | MCP-1 | 2.1 (0.6, 10.2) | 2.8 (0.6, 11.9) | 0.96 |
| Collecting duct | Aquaporin-2 | MCP-1 | 26 (8.3, 93.5) | 16.2 (3.6, 67.3) | 0.15 |
| Papillary duct | Cytokeratin 19 | MCP-1 | 14.5 (3.2, 48.4) | 2.5 (0.7, 12.2) | <0.01* |
| Proximal tubule | URAT1 | NGAL | 19.1 (5.1, 59.2) | 8.3 (2.3, 43.8) | 0.03* |
| Ascending thin limb | Aquaporin-1 | NGAL | 50.7 (22.5, 172.5) | 8 (0.4, 54.5) | <0.01* |
| Thick limb | Uromodulin | NGAL | 62.8 (19.3, 198) | 35.4 (9.5, 130.2) | 0.13 |
| Distal tubule | SLC12A3 | NGAL | 4 (1.9, 16.1) | 4.6 (1.5, 17.2) | 0.94 |
| Collecting duct | Aquaporin-2 | NGAL | 77.3 (27, 219.4) | 38.7 (11.6, 139.5) | 0.03* |
| Papillary duct | Cytokeratin 19 | NGAL | 30.8 (5.9, 111.1) | 5.8 (1.2, 25.7) | <0.01* |
| Proximal tubule | URAT1 | OPN | 5.5 (1.6, 34.4) | 5.9 (1, 24.6) | 0.56 |
| Ascending thin limb | Aquaporin-1 | OPN | 11 (2.8, 40.8) | 4.3 (0.5, 23.3) | 0.05* |
| Thick limb | Uromodulin | OPN | 12.3 (2.5, 33) | 4.8 (1.3, 26.9) | 0.23 |
| Distal tubule | SLC12A3 | OPN | 2.7 (0.7, 15.8) | 3.8 (0.8, 17.7) | 0.76 |
| Collecting duct | Aquaporin-2 | OPN | 14.8 (3.1, 37.6) | 9.5 (2.5, 48.3) | 0.83 |
| Papillary duct | Cytokeratin 19 | OPN | 8.3 (1.6, 36.5) | 4 (0.7, 20.9) | 0.11 |
Data are presented as medians (25th percentile, 95th percentile) of the natural log of the respective marker-associated urinary extracellular vesicles/mg creatinine value. MCP-1, monocyte chemoattractant protein-1; NGAL, neutrophil gelatinase-associated protein; OPN, osteopontin; URAT1, urate transporter 1. Statistical differences between groups were analyzed with a Wilcoxon rank sum test. P < 0.05 was considered statistically significant.
*
Statistical significance.