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Kidney Week

Abstract: FR-PO1018

The Effect of Donor-Recipient Size Mismatch on Graft Survival Is Modified by Kidney Transplant Recipient and Donor Age

Session Information

Category: Transplantation

  • 1702 Transplantation: Clinical and Translational


  • Lepeytre, Fanny, Centre de Recherche du CHUM, Montreal, Quebec, Canada
  • Delmas-Frenette, Catherine, None, Westmount, Quebec, Canada
  • Zhang, Xun, McGill University Health Centre, Montreal, Quebec, Canada
  • Sapir-Pichhadze, Ruth, McGill University, Montreal, Quebec, Canada
  • Foster, Bethany J., McGill University Health Center, Montreal, Quebec, Canada
  • Cardinal, Heloise, Centre de Recherche du CHUM, Montreal, Quebec, Canada

Advanced donor age, recipient age and donor-recipient size mismatch are all independent risk factors for poorer kidney graft survival, but how these variables interact is unknown.


We performed a retrospective cohort study using the Scientific Registry of Transplant Recipient (SRTR). All first deceased donor kidney transplantations performed between Jan 1st 2000 and Jan 1st 2015 in recipients aged ≥18 years were included. We used multivariable Cox proportional hazards models to assess the association between donor-recipient body surface area (BSA) ratio (≤ 0.9 vs. >0.9) and overall graft survival, defined as death with function, return to dialysis or retransplantation. We considered interactions between BSA ratio and each of recipient age (≤54 vs. >54 years; the median age) and donor age (≤60 vs. >60 years), as well as a 3-way interaction term of BSA ratio by recipient age and donor age.


From a total of 118,101 patients, 39,330 (33.3%) experienced graft loss over a median follow-up of 4.8 years. The 3-way donor-recipient BSA ratio by donor age by recipient age interaction was statistically significant (p=0.02). Among recipients ≤54 years, a donor-recipient BSA ratio ≤ 0.9 was associated with a higher risk of graft failure when donors were younger than 60 (hazard ratio (HR): 1.11, 95% confidence interval (CI) 1.07-1.14); when the donor was older than 60, donor-recipient BSA ratio ≤ 0.9 was not associated with graft survival (HR: 0.92, 95% CI 0.81-1.04). In recipients >54 years, donor-recipient BSA ratio ≤ 0.9 was significantly associated with graft failure regardless of donor age (HR: 1.07, 95% CI 1.03-1.10 for donors ≤60 and HR: 1.09, 95% CI 1.02-1.16) for donors >60.


We find donor-recipient size mismatch to have a small but significant impact on graft survival in all but younger recipients of older deceased donors. We hypothesize that in the latter group, the adverse impact of donor age superscedes the effect of donor-recipient size mismatch, and a size mismatch should not be considered as adversely affect graft survival in this patient population.