Table 1.

Comparison of two biopsies from the same kidney

Biopsy CharacteristicFirst Biopsy (n=64)Second Biopsy (n=64)P Valuea
Wedge (versus needle)40/48 (83.3)10/48 (20.8)<0.001
Frozen tissue (versus paraffin-embedded tissue)37/39 (94.9)37/39 (94.9)NE
Number of glomeruli assessed53.8±28.449.7±40.00.81
Percentage of global sclerosis11.5±10.711.0±10.90.84
Biopsy findings, if reportedb
 Tubular atrophy (36 pairs)0.61±0.731.03±0.290.01
 Interstitial fibrosis (62 pairs)0.68±0.701.02±0.420.01
 Interstitial inflammation (3 pairs)1.00±0.000.33±0.58NE
 Vascular damage (55 pairs)0.91±0.821.11±0.500.19
 Arteriolar hyalinosis (3 pairs)0.33±0.580.33±0.58NE
 Acute tubular necrosis (7 pairs)0.29±0.490.29±0.49NE
Missing biopsy information
 Wedge versus needle biopsy11/64 (17.2)5/64 (7.8)0.14
 Tissue processing method not indicated23/64 (35.9)4/64 (6.3)<0.001
 Tubular atrophy23/64 (35.9)8/64 (12.5)0.003
 Interstitial fibrosis2/64 (3.1)0/64 (0.0)NE
 Interstitial inflammation32/64 (50.0)57/64 (89.1)<0.001
 Vascular damage7/64 (10.9)2/64 (3.1)0.11
 Arteriolar hyalinosis39/64 (60.9)54/64 (84.4)0.01
 Acute tubular necrosis48/64 (75.0)49/64 (76.6)0.81
  • 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 1 for details.

  • b 0, none; 1, mild; 2, moderate; 3, severe.