TABLE 3.
Main demographic and clinical characteristics of patients with ABMR and DSA compared to ABMR without HLA-DSA (left) and to non-ABMR with HLA-DSA (right).
| ABMR+ DSA+ (n = 31) | ABMR+ DSA– (n = 16) | P-value | ABMR– DSA+ (n = 17) | P-value vs. ABMR+ DSA+ | |
| AT TRANSPLANTATION | |||||
| Recipient age (years) [mean (SD)] | 45.6 (16.0) | 51.3 (15.9) | 0.25 | 49.1 (17.9) | 0.49 |
| Recipient gender (female) [n (%)] | 15 (48.4%) | 8 (50.0%) | 1.00 | 7 (41.2%) | 0.77 |
| Type of donor (deceased) [n (%)] | 29 (93.5%) | 12 (75.0%) | 0.16 | 17 (100%) | 0.53 |
| Donor age (years) [mean (SD)] | 44.2 (17.6) | 51.8 (13.5) | 0.14 | 48.9 (20.2) | 0.41 |
| HLA-DSA+ at transplantation [n/total (%)]* | 11/27 (40.7%) | 1/12 (8.3%) | 0.090 | 6/16 (37.5%) | 1.00 |
| Thymoglobulin induction [n (%)] | 6 (19.4%) | 4 (25.0%) | 0.38 | 6 (35.3%) | 0.32 |
| AT BIOPSY | |||||
| Biopsy time after KT (months) [median (IQR)] | 36.7 (14–98) | 15.2 (8–80) | 0.27 | 18.5 (14–64) | 0.50 |
| Immunosuppression at biopsy [ n (%)] | |||||
| Prednisone | 25 (80.6%) | 13 (81.3%) | 1.00 | 14 (82.4%) | 1.00 |
| Calcineurin inhibitors | 21 (67.7%) | 15 (93.8%) | 0.070 | 15 (88.2%) | 0.17 |
| Mycophenolate | 28 (90.3%) | 11 (68.8%) | 0.10 | 16 (94.4%) | 1.00 |
| mTOR inhibitors | 11 (35.5%) | 3 (18.8%) | 0.32 | 3 (17.6%) | 0.32 |
| ABMR characteristics in biopsy [ n (%)] | N/A | N/A | |||
| Microvascular inflammation (g + PTC ≥ 2) | 25 (80.6%) | 14 (87.5%) | 0.70 | ||
|
Glomerulitis (g ≥ 1) |
24 (77.4%) | 12 (75.0%) | 1.00 | ||
| PTC (PTC ≥ 1) | 25 (80.6%) | 9 (56.3%) | 0.096 | ||
| C4d deposits (C4d ≥ 2) | 11 (35.5%) | 5 (31.3%) | 0.76 | ||
| Chronic transplant glomerulopathy [yes (%)] | 16 (51.6%) | 6 (37.5%) | 0.54 | ||
| EM CTG or PTCML [yes/total (%)]** | 24/29 (82.8%) | 5/9 (55.6%) | 0.17 | ||
| Serum creatinine [mg/dl, mean (SD)] | 1.9 (0.9) | 2.3 (1.8) | 0.21 | 1.3 (0.4) | 0.024 |
| eGFR [ml/min, mean (SD)] | 46.6 (22.8) | 40.6 (22.7) | 0.39 | 58.1 (16.1) | 0.074 |
| Pr/Cr [mg/g, median (IQR)] | 389.0 (167–994) | 604 (144–910) | 0.98 | 155.9 (111–244) | 0.004 |
ABMR, antibody-mediated rejection; CTG, chronic transplant glomerulopathy; DSA, HLA donor specific antibodies; eGFR, estimated glomerular filtration rate; EM, electron microscopy; IQR, interquartile range; KT, kidney transplantation; Pr/Cr, urinary protein to creatinine ratio; PTC, peritubular capillaries; PTCML, peritubular capillary multilayering; SD, standard deviation. *From 55 patients with pre-transplant SAB assay performed; **From 38 patients with EM study. A significant p-value is indicated by a bold value.