Features of Antibody-Mediated Rejection (AMR) in Early and Late Protocol and Indication Renal Allograft Biopsies
Depts of Medicine,
Pathology,
Surgery, University of Maryland, Baltimore, MD
Meeting: 2013 American Transplant Congress
Abstract number: B979
The prevalence of serologic and histologic features of AMR in early and late biopsies and in association with graft fuction has not been well-recognized. We examined these features in 1101 biopsy specimens in 861 patients, biposied Dec. 2009-Apr. 2012.
Table 1 summarizes these features.
| <12 mo | >12 mo | |||
|---|---|---|---|---|
| Protocol | Indication | Protocol | Indication | |
| DSA | 19.7% | 26.7% | 27.0% | 41.1% |
| ACR | 3.9% | 10.2% | 1.4% | 9.0% |
| g score>0 | 7.3% | 10.6% | 12.1% | 32.6% |
| cg score>0 | 1.9% | 5.3% | 6.4% | 27.0% |
| MV inflammation | 10.1% | 18.4% | 14.9% | 42.2% |
| Glom CD68 >12 | 7.7% | 14.4% | 14.9% | 31.4% |
| PTC C4d+ | 17.4% | 37.8% | 16.3% | 38.2% |
| TG by EM | 2.3% | 5.3% | 7.1% | 30.0% |
| Glom endothelial injury | 7.4% | 11.5% | 7.1% | 7.1% |
| cv score>0 | 59.6% | 73.9% | 66.4% | 87.1% |
Acute cellular rejection was not associated with time of biopsy, but more likely in inidication biopsies (aOR:3.5, p<0.001,CI:1.9-6.6). C4d positivity was not related to time but type of biopsy (aOR:3.0, p<0.001,CI:2.2-4.1). While, DSA was associated with both (aOR:1.8, p<0.001,CI:1.4-2.3 for>12mo; aOR:1.7, p=0.001,CI:1.2-2.2 for indication). Transplant glomerulopathy (TG) was more likely in late and indication biopsies (aOR:8.3, p<0.001,CI:4.7-14.7; aOR:3.4, p<0.001,CI:1.9-6.1, respectively). So was Glomerulitis &/or capillaritis (MV inflammation) (aOR: 2.7, p<0.001,CI:2.0-3.7 and aOR:2.9, p<0.001,CI:2.1-4.2, respectively). Glomerular endothelial cell injury by EM was not associated with the time or type of biopsy. Likelihood of higher g score increased with late biopsies (aRRR:2.7, p<0.001 for g1; 3.6, p<0.001 for g2; 11.4, p=0.001 for g3). Glomerular CD68+ cells>12 was also associated with the two (aOR:2.3, p<0.001,CI:1.6-3.4 for late, and aOR:2.5, p<0.001,CI:1.8-3.5 for indication biopsies). Class I DSA alone was only associated with type of biopsy (aOR:1.9, p,0.04,CI:1.0-3.4), class II DSA only with time (aOR:1.9, p<0.001,CI:1.4-2.7), and class I & II DSA with both (aOR:3.1, p<0.001,CI:1.7-5.5 for indication, and aOR:2.0, p=0.002,CI:13-3.2 for late biopsies, respectively).
Our observation in this large cohort shows that ACR, endothelial injury, and C4d are not time-related. In contrast, class II DSA +/- class I, MV inflammation, higher g score, CD68+ cells>12, and TG are associated with time and often type of biopsy. This suggest that in later stages post-transplat, class II DSA-induced graft injury is more mediated by cellular elements rather than complement activation.
To cite this abstract in AMA style:
Haririan A, Papadimitriou J, Klassen D, Ugarte R, Bromberg J, Kukuruga D, Drachenberg C. Features of Antibody-Mediated Rejection (AMR) in Early and Late Protocol and Indication Renal Allograft Biopsies [abstract]. Am J Transplant. 2013; 13 (suppl 5). https://atcmeetingabstracts.com/abstract/features-of-antibody-mediated-rejection-amr-in-early-and-late-protocol-and-indication-renal-allograft-biopsies/. Accessed May 14, 2025.« Back to 2013 American Transplant Congress