Table 2.
Comparison of urine tests between glomerular and tubulointerstitial disease.
| Characteristic | Glomerular | Tubulointerstitial | Mixed | P-value [1] | P-value [2] |
|---|---|---|---|---|---|
| Dipstick | |||||
| Dipstick performed | 121 (95%) | 89 (97%) | 148 (93%) | ||
| Specific gravity | 1.020 (1.015, 1.025) | 1.015 (1.010, 1.020) | 1.020 (1.015, 1.020) | <0.001 | <0.001 |
| pH | 6.0 (5.5, 6.5) | 6.0 (5.5, 6.5) | 6.0 (5.5, 6.5) | 0.66 | 0.80 |
| Protein | 3 (2, 3) | 1 (0, 2) | 3 (1, 3) | <0.001 | <0.001 |
| Ketone | 10 (8%) | 12 (13%) | 10 (7%) | 0.20 | 0.22 |
| Blood* | 3 (1, 4) | 1 (1, 3) | 2 (1, 3) | <0.001 | <0.001 |
| Leukocyte | 0 (0, 0) | 0 (0, 1) | 0 (0, 1) | 0.02 | 0.007 |
| Urine Microscopy | |||||
| Microscopy performed | 122 (96%) | 85 (92%) | 149 (93%) | ||
| RBC cast* | 19 (17%) | 5 (7%) | 13 (10%) | 0.08 | 0.06 |
| Dysmorphic RBC* | 35 (32%) | 7 (10%) | 21 (16%) | <0.001 | <0.001 |
| RBC cell* | 85 (78%) | 46 (68%) | 100 (76%) | 0.27 | 0.13 |
| WBC cast | 4 (3%) | 2 (2%) | 2 (1%) | 0.57 | 0.69 |
| WBC cell | 12 (10%) | 19 (22%) | 24 (16%) | 0.05 | 0.01 |
| RTE cell | 30 (25%) | 35 (41%) | 44 (30%) | 0.04 | 0.01 |
| RTE cast | 3 (2%) | 10 (12%) | 3 (2%) | 0.001 | 0.007 |
| Granular cast | 45 (37%) | 42 (49%) | 53 (36%) | 0.09 | 0.08 |
| Urine biomarkers | |||||
| Glomerular disease | |||||
| Albumin | 1.25 (0.49, 3.19) | 0.09 (0.03, 0.42) | 0.94 (0.11, 2.54) | <0.001 | <0.001 |
| Tubular injury and health | |||||
| IL-18 | 104.4 (50.6, 217.9) | 75.1 (32.7, 184.1) | 84.7 (40.9, 202.4) | 0.07 | 0.03 |
| KIM-1 | 4387 (2042, 10203) | 3532 (1827, 6792) | 3197 (1644, 6230) | 0.03 | 0.12 |
| MCP-1 | 1407 (586, 3939) | 1799 (787, 4652) | 1433 (517, 2991) | 0.15 | 0.21 |
| YKL-40 | 3593 (937, 14265) | 6086 (1351, 21951) | 9905 (1226, 75259) | 0.04 | 0.13 |
| NGAL | 96 (22, 494) | 200 (56, 773) | 220 (52, 804) | 0.02 | 0.01 |
| Uromodulin | 1.41 (0.84, 2.24) | 1.13 (0.72, 1.78) | 0.97 (0.58, 1.76) | <0.001 | 0.03 |
| Interstitial Nephritis | |||||
| Interleukin-9 | 0.29 (0.14, 0.70) | 0.36 (0.13, 1.45) | 0.47 (0.20, 1.37) | 0.04 | 0.46 |
| TNF-α | 0.22 (0.09, 0.75) | 0.42 (0.15, 2.38) | 0.39 (0.13, 2.64) | <0.001 | <0.001 |
Kruskal-Wallis or rank sum and chi-square test performed; P-value [1] compares all three groups; p-value [2] compares glomerular vs. tubular; *excludes those with bladder catheters (n = 47); urine microscopy available in 359; urine biomarker values represent urine biomarker to urine creatinine ratio; all biomarkers are pg per mg of urine creatinine except albumin (mg/mg) and uromodulin (microg/mg). Data presented as count (percentage) or median (interquartile range).