Table 1.
Conventional diagnoses in 703 biopsies
| Conventional Diagnosis | All Biopsies (n=703) | All Kidneysa (n=564) | Kidneys That Did Not Progress to Failure (n=436) | Kidneys That Progressed to Failure (n=128) | P Valueb (Failed Versus Working) |
|---|---|---|---|---|---|
| Rejection-related processes, n (%) | |||||
| Pure TCMR | 67 (10) | 56 (10) | 50 (11)a | 6 (5) | 0.02 |
| Pure ABMR | 110 (16) | 94 (17) | 47 (11) | 47 (37)a | <0.001 |
| C4d-positive ABMR | 30 (4) | 27 (5) | 13 (3) | 14 (11)a | <0.001 |
| C4d-negative ABMR | 80 (11) | 67 (12) | 34 (8) | 33 (26)a | <0.001 |
| Mixed rejection | 28 (4) | 12 (2) | 8 (2) | 4 (3) | 0.48 |
| Borderline | 89 (13) | 63 (11) | 56 (13)a | 7 (5) | 0.02 |
| Transplant glomerulopathy | 27 (4) | 24 (4) | 16 (4) | 8 (6) | 0.20 |
| Other processes, n (%) | |||||
| PVN | 25 (4) | 16 (3) | 11 (3) | 5 (4) | 0.41 |
| GN | 81 (12) | 75 (13) | 55 (13) | 20 (16) | 0.38 |
| Relatively normal | 180 (26) | 147 (26) | 133 (31)a | 14 (11)c | <0.001 |
| Atrophy fibrosis of unknown significance | 72 (10) | 58 (10) | 44 (10) | 14 (11) | 0.78 |
| Other uncommon diagnosed | 24 (3) | 19 (3) | 16 (4) | 3 (2) | 0.59 |
| Total | 703 | 564 | 436 | 128 |
We selected one random biopsy per kidney. Significant differences in progression to failure highlight that the group is overrepresented in the diagnostic category.
Chi-squared and Fisher exact statistical tests.
Of 14 failures after a study biopsy that showed relatively normal histology, 8 failures were attributable to late events apparently unrelated to the study biopsy (ABMR, GN, or nonadherence), 3 failures were missed diagnoses of ABMR, and 3 failures have incomplete follow-up records.
Other diagnoses included C4d deposition without morphologic evidence for active rejection (n=6), missing diagnosis (n=1), and biopsies with no clear diagnosis, including probable TCMR (n=2), probably normal (n=7), probable atrophy fibrosis of unknown significance (n=5), suspicious for ABMR (n=2), and probable borderline (n=1).