Transfusion of leukoreduced blood products and risk of antibody-mediated rejection of renal allografts

Abstract

Background

Antibody-mediated rejection (AMR) is a major barrier to the long-term function of renal allografts. Platelets and leukocytes, which may be present in red blood cell (RBC) units, express HLA antigens that may increase the risk of AMR by inducing or increasing humoral sensitization to HLA.

Methods

A retrospective cohort study of HLA-incompatible renal transplant recipients between 2004-2015 was conducted. Data on apheresis platelet and leukoreduced RBC transfusions within four weeks of transplantation, demographic information, and biopsy-proven AMR were collected from medical records and the Scientific Registry of Transplant Recipients (SRTR). Patients were evaluated until they showed evidence of AMR or until one year post-transplant, whichever came first. Multivariable analysis with Cox modeling was performed.

Results

Of 244 individuals, 182(74.6%) received RBCs and 20(8.2%) of those also received platelets. During the first year post-transplant, 97(39.8%) had AMR. RBC alone or RBC and platelet transfusions were not associated with increased risk of AMR after adjustment for panel reactive antibody, years on dialysis, HLA antibody strength, and number of therapeutic plasma exchange treatments (adjusted hazard ratio [adjHR]=1.00,95% confidence interval [95%CI]=0.59-1.69 and adjHR=0.68,95%CI=0.28-1.68, respectively). For each one unit increase in RBC transfusions, there was no association with AMR (adjHR=0.94,0.85-1.05). Only HLA antibody strength prior to transplantation was associated with AMR (adjHR=2.23,95%CI=1.10-4.52, cytotoxic crossmatch compared to crossmatch negative but detectable donor-specific HLA antibodies).

Conclusions

Patients who receive an HLA-incompatible transplant who are transfused with leukoreduced RBCs or platelets in the peri-transplant period are at no higher risk of AMR than non-transfused patients.