The influence of deceased donor age and old-for-old allocation on kidney transplant outcome

Abstract

Background: Transplantation of older deceased donor kidneys is gaining wide acceptance in most countries. Many previous studies have concluded that advanced donor age negatively impacts posttransplant outcome, but detailed data on the extent to which a few years increase in donor age will influence early graft function and graft survival are scarce.

Methods: We used the Organ Procurement and Transplantation Network database (cohort 1994-2006, n=99,860 recipients) to evaluate the effect of deceased donor age on posttransplant results and to obtain regression models which are relevant to guide clinical organ allocation policies. In addition, we simulated the effect that old-for-old allocation would have on transplant outcome.

Results: In the context of other risk factors, donor age increased the risk of delayed graft function and graft failure with odds and hazard ratios of 1.02 and 1.01, respectively. Absolute delayed graft function risk increased by 0.35% to 0.37%, and graft survival decreased with each year increase in donor age. Kidney discard rates in the United States increased with donor age, up to 66.9% for 65 years and older donors. In our simulation, we found that old-for-old kidney allocation would have no large impact on overall renal transplant outcome.

Conclusions: This study shows that donor age strongly influences posttransplant outcome, not only in the upper extremes but also for the whole range of donor ages more than or equal to 11 years. Implementation of old-for-old kidney allocation is likely to be safe. Such a policy could reduce waiting time for aged candidates, but it will not necessarily improve overall kidney transplant outcome.