Table 3.

Comparison of biopsies from discarded kidneys and randomly matched controls

Biopsy CharacteristicKidney 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±41.151.4±32.90.86
Percentage of global sclerosis (164 pairs)17.1±15.45.0±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±0.470.60±0.54<0.001
 Interstitial fibrosis (150 pairs)0.97±0.520.54±0.56<0.001
 Interstitial inflammation (38 pairs)0.75±0.550.45±0.500.04
 Vascular damage (127 pairs)1.05±0.760.64±0.630.001
 Arteriolar hyalinosis (24 pairs)0.38±0.510.58±0.650.51
 Acute tubular necrosis (18 pairs)0.78±0.970.28±0.460.22
Missing biopsy information
 Wedge versus needle biopsy18/83 (21.7)38/166 (22.9)0.79
 Tissue processing method not indicated29/83 (34.9)64/166 (38.6)0.51
 Tubular atrophy27/83 (32.5)51/166 (30.7)0.72
 Interstitial fibrosis2/83 (2.4)12/166 (7.2)0.08
 Interstitial inflammation43/83 (51.8)85/166 (51.2)0.92
 Vascular damage6/83 (7.2)29/166 (17.5)0.01
 Arteriolar hyalinosis44/83 (53.0)99/166 (59.6)0.27
 Acute tubular necrosis47/83 (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.