Table 3.
Comparison of biopsies from discarded kidneys and randomly matched controls
| Biopsy Characteristic | Kidney Discarded for Biopsy Findings (n=83) | Randomly Matched Control (n=166) | P Valuea |
|---|---|---|---|
| Wedge (versus needle) | 34/51 (66.7) | 72/101 (71.3) | 0.55 |
| Frozen tissue (versus paraffin-embedded tissue) | 32/33 (97.0) | 57/65 (87.7) | NE |
| Number of glomeruli assessed (164 pairs) | 53.8±41.1 | 51.4±32.9 | 0.86 |
| Percentage of global sclerosis (164 pairs) | 17.1±15.4 | 5.0±5.9 | <0.001 |
| Percentage of global sclerosis >20% | 27/83 (32.5) | 5/166 (3.0) | <0.001 |
| Biopsy findings, if reportedb | |||
| Tubular atrophy (80 pairs) | 1.07±0.47 | 0.60±0.54 | <0.001 |
| Interstitial fibrosis (150 pairs) | 0.97±0.52 | 0.54±0.56 | <0.001 |
| Interstitial inflammation (38 pairs) | 0.75±0.55 | 0.45±0.50 | 0.04 |
| Vascular damage (127 pairs) | 1.05±0.76 | 0.64±0.63 | 0.001 |
| Arteriolar hyalinosis (24 pairs) | 0.38±0.51 | 0.58±0.65 | 0.51 |
| Acute tubular necrosis (18 pairs) | 0.78±0.97 | 0.28±0.46 | 0.22 |
| Missing biopsy information | |||
| Wedge versus needle biopsy | 18/83 (21.7) | 38/166 (22.9) | 0.79 |
| Tissue processing method not indicated | 29/83 (34.9) | 64/166 (38.6) | 0.51 |
| Tubular atrophy | 27/83 (32.5) | 51/166 (30.7) | 0.72 |
| Interstitial fibrosis | 2/83 (2.4) | 12/166 (7.2) | 0.08 |
| Interstitial inflammation | 43/83 (51.8) | 85/166 (51.2) | 0.92 |
| Vascular damage | 6/83 (7.2) | 29/166 (17.5) | 0.01 |
| Arteriolar hyalinosis | 44/83 (53.0) | 99/166 (59.6) | 0.27 |
| Acute tubular necrosis | 47/83 (56.6) | 119/166 (71.7) | 0.01 |
Data are presented as the fraction (%) or mean±SD. NE, not estimable due to too few discordant pairings.
a
P values for binary data were generated from logistic regression for repeated measures using generalized estimating equations and taking into account the nested correlation induced by kidney laterality within donor (5). P values for parametric data were generated from a signed rank test on the matched case-control differences for clustered data (6). See Supplemental Table 3 for details.
b
0, none; 1, mild; 2, moderate; 3, severe.