Table 4.
Histologic analysis of graft failure
| Variable | No dnDSAs (n=34) | C1q− dnDSAs (n=5) | C1q+ dnDSAs (n=7) | P Value |
|---|---|---|---|---|
| Median time between transplant and biopsy (d) | 2032 (154–4115) | 2073 (1026–4471) | 1528 (373–3241) | 0.4 |
| Median time between biopsy and graft loss (d) | 319 (0–1747) | 49 (42–939) | 396 (248–841) | 0.4 |
| Banff scores | ||||
| i | 1.02±0.67 | 1.20±0.44 | 1.28±1.11 | 0.8 |
| t | 0.56±0.79 | 0.40±0.90 | 0.14±0.38 | 0.4 |
| g | 0.21±0.60 | 0.20±0.45 | 0.00±0.00 | 0.6 |
| ptc | 0.13±0.34 | 0.40±0.89 | 0.57±0.79 | 0.2 |
| v | 0.00±0.00 | 0.00±0.00 | 0.00±0.00 | 1.0 |
| ci | 2.12±0.65 | 2.00±0.71 | 1.85±0.69 | 0.6 |
| ct | 2.06±0.66 | 2.20±0.84 | 1.71±0.76 | 0.4 |
| cv | 1.03±0.89 | 1.16±1.14 | 1.00±0.70 | 0.6 |
| cg | 0.94±1.22 | 1.40±1.14 | 1.71±1.11 | 0.2 |
| C4d>0, n (%) | 5 (23) | 1 (20) | 2 (29) | 0.5 |
| Banff diagnosis, n (%) | ||||
| Chronic AMRa | 0 (0) | 5 (100) | 6 (86) | 0.001 |
| Suspicious AMRb | 6 (18) | 0 (0) | 0 (0) | |
| Interstitial fibrosis/tubular atrophy | 20 (59) | 0 (0) | 1 (14) | |
| Transplant glomerulopathy | 8 (23) | 0 (0) | 0 (0) | |
| AMR characteristics, n (%) | ||||
| C4d+ AMR | 1 (20) | 2 (33) | ||
| C4d− AMR | 4 (80) | 4 (67) |
Median values are expressed with minimum and maximum in parentheses. Values expressed with a plus/minus sign are the mean±SD.
a
Biopsies showing histologic evidence of chronic tissue injury (cg>0, cv>0) and dnDSA were considered as chronic AMR, even if evidence of current/recent antibody interaction with vascular endothelium (C4d>0 or g+ptc≥2) was absent.
b
Biopsies showing both histologic evidence of acute (g>0, ptc>0, v>0) or chronic (cg>0, cv>0) tissue injury and evidence of current/recent antibody interaction with vascular endothelium (C4d>0 or g+ptc≥2), but no dnDSA, were designated as suspicious AMR.