Abstract: TH-PO0949
Repeat Human Leukocyte Antigen Mismatches Are Not Associated with an Increased Risk of Rejection and Graft Loss in Second Kidney Transplant Recipients: A Contemporary Nationwide Retrospective Cohort Study
Session Information
- Transplantation: Clinical - Glomerular Diseases, Infections, and Rejection
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2102 Transplantation: Clinical
Authors
- Pipeleers, Lissa, Universitair Ziekenhuis Brussel, Brussels, Belgium
- de Ferrante, Hans, Eurotransplant International Foundation, Leiden, Netherlands
- Moreau, Juliette Françoise, Universitair Ziekenhuis Brussel, Brussels, Belgium
- Darius, Tom, University Clinics Saint Luc, Brussels, Belgium
- De Pelsmaeker, Steffi, Rode Kruis Vlaanderen, Mechelen, Vlaanderen, Belgium
- Evenepoel, Anton, Universitair Ziekenhuis Brussel, Brussels, Belgium
- Gambino, Giuseppe, LHUB-ULB Bruxelles, Brussels, Belgium
- Hellemans, Rachel, Universitair Ziekenhuis Antwerpen, Edegem, Flanders, Belgium
- Holovska, Vanda, LHUB-ULB Bruxelles, Brussels, Belgium
- Kerkhofs, Johan, Rode Kruis Vlaanderen, Mechelen, Vlaanderen, Belgium
- Naesens, Maarten, UZ Leuven, Leuven, Flanders, Belgium
- Schmitt, Justine, CHU Liège, Liège, Belgium
- Streel, Corentin, University Clinics Saint Luc, Brussels, Belgium
- Tieken, Ineke, Eurotransplant International Foundation, Leiden, Netherlands
- Van Laecke, Steven, Universitair Ziekenhuis Gent, Ghent, Flanders, Belgium
- Weekers, Laurent E., CHU Liège, Liège, Belgium
- Emonds, Marie-Paule, Rode Kruis Vlaanderen, Mechelen, Vlaanderen, Belgium
- Wissing, Karl Martin, Universitair Ziekenhuis Brussel, Brussels, Belgium
Group or Team Name
- KARMA Study Team.
Background
Historically, repeat human leukocyte antigen (HLA) mismatches (RMMs) have been associated with an increased risk of rejection and graft loss, before sensitive techniques to detect anti-HLA antibodies were available. Systematic avoidance of donors with RMMs results in an increased waiting time for repeat kidney transplant (KT) candidates. We hypothesized that RMMs are no longer associated with an increased risk of rejection and graft loss as Luminex single antigen bead (SAB) assays can, at present, prevent the transplantation of RMMs against preformed donor-specific antibodies (DSAs).
Methods
We have investigated the outcomes of all second KT recipients, who had been waitlisted for their second KT in Belgium after 2010 (n=336). Granular HLA-typing data and Luminex sensitisation data were collected. First year biopsy-proven rejections (BPR) were defined according to the Banff 2022 Classification and included T cell-mediated rejection (TCMR) (acute TCMR Banff IA or higher and chronic active TCMR phenotypes) and antibody-mediated rejection (AMR) (active AMR, chronic active AMR and chronic AMR phenotypes).
Results
When considering HLA A, B, DR and DQ antigens, 44 recipients were transplanted with at least one RMM (RMM+), compared to 292 recipients with no RMM (RMM-). Recipients with a preformed DSA against a RMM were excluded. There was no difference in death-censored graft survival (DCGS) between both groups at one and five years: 96% and 86% for the RMM- group compared to 93% and 87% for the RMM+ group, respectively (P=1.0). No difference was observed in the proportion of second KT recipients with at least one BPR (12.3% for RMM- versus 4.6% for RMM+; P =0.2) or TCMR (9.6% for RMM- versus 4.6% for RMM+; P=0.4). In the RMM+ group, no AMRs were observed.
Conclusion
Our data support the assumption that transplanting a kidney graft with a RMM, in the absence of a detectable SAB donor-specific antibody against the RMM, is safe in terms of first-year biopsy proven rejection as well as short- and long-term death-censored graft survival.