Table 2.
Associations of urine cathepsin D with kidney histopathological features in the BKBC
| Histopathologic lesion | Severity | N (% total) | Mean (SD) urine cathepsin D in ng/mg Cr | Adjusted difference in cathepsin D concentration in ng/mg Cr (95% CI)* | Trend test P value* |
|---|---|---|---|---|---|
| Tubulointerstitial compartment | |||||
| Interstitial fibrosis and tubular atrophy | ≤50% >50% | 23 31 | 108.1 (92.8) 197.3 (126.5) | Ref. 83.7 (21.7, 145.7) | 0.043 |
| Tubulointerstitial inflammation, with fibrosed area | Mild, 11–25% Moderate, 26–50%, or severe, >50% | 33 21 | 132.1 (121.4) 202.0 (109.7) | Ref. 75.5 (14.3, 136.7) | 0.009 |
| Tubulointerstitial inflammation, with preserved area | None, <10% Mild, 11–25%, moderate, 26–50%, or severe, >50% | 47 4 | 149.9 (114.8) 228.6 (87.5) | Ref. 59.9 (−54.6, 174.3) | 0.60 |
| Acute tubular injury | None | 28 | 148.1 (117.3) | Ref. | 0.46 |
| Mild or moderate | 26 | 171.4 (125.8) | 24.4 (−38.3, 87.0) | ||
| Glomerular compartment | |||||
| Global glomerulosclerosis | None <10%, or mild, 11–25% | 15 | 147.5 (161.2) | Ref. | 0.55 |
| Moderate, 26–50% | 22 | 138.8 (99.0) | −28.7 (−107.5, 50.0) | ||
| Severe, >50% | 19 | 179.2 (110.1) | 20.9 (−62.5, 104.3) | ||
| Segmental glomerulosclerosis | None, <10% Mild, 11–25%, moderate, 26–50%, or severe, >50% | 44 10 | 147.0 (103.5) 154.3 (106.0) | Ref. 3.8 (−66.9, 74.6) | 0.73 |
| Mesangial matrix expansion | Mild or moderate Severe | 19 36 | 131.5 (137.1) 170.2 (111.6) | Ref. 24.6 (−41.6, 90.9) | 0.91 |
| Mesangial hypercellularity | None or mild Moderate | 14 28 | 161.3 (109.3) 121.8 (77.3) | Ref. −44.3 (−107.9, 19.3) | 0.70 |
| Severe | 10 | 198.6 (148) | 30.8 (−49.6, 111.2) | ||
| Vascular compartment | |||||
| Arterial sclerosis | Mild or moderate | 23 | 174.8 (145.6) | Ref. | 0.39 |
| Severe | 30 | 150.1 (100.7) | −11.5 (−77.3, 54.4) | ||
| Arteriolar hyalinosclerosis | Mild or moderate Severe | 16 38 | 200.9 (157.3) 141.8 (99.2) | Ref. −56.3 (−123.6, 11.0) | 0.052 |
Number (%) of missing values for each variable in the overall study population: interstitial fibrosis and tubular atrophy 2 (4); tubulointerstitial inflammation, with fibrosed area 2 (4); tubulointerstitial inflammation, with preserved area 5 (9); acute tubular injury 2 (4); global glomerulosclerosis 0 (0); segmental glomerulosclerosis 2 (4); mesangial matrix expansion 1 (2); mesangial hypercellularity 4 (7); arterial sclerosis 3 (5); arteriolar hyalinosclerosis 2 (4).
Adjustment for age and sex. We performed calculations using all available histopathologic lesion severity categories instead of combined categories. Histopathologic lesion severities were collapsed to create balanced distributions. Trend test P values were calculated for original, noncollapsed histopathologic lesion severity categories. Cr, creatinine; Ref., referent.