Effect of donor-recipient age difference on graft function and survival in live-donor kidney transplantation

Background. Renal transplant recipients of older deceased-donor kidneys have reduced allograft survival. However, the impact of donor-recipient age difference on live-donor kidney transplant outcomes, where donors are older than recipients, remains unclear. Methods. Using the Australia and New Zealand Dialysis and Transplant Registry, all primary live-donor kidney transplant recipients in Australia from 1991 to 2006 were studied. Donor-recipient age difference was divided into four categories (donor-recipient <-10, -10-20, 20-29 and >= 30 years). Outcome measures included serum creatinine, graft and patient survival. Results. In the adjusted model, donor-recipient age difference of >= 30 years showed a trend towards increased risk of graft failure compared with a difference of -10-20 years during the first year post-transplant only (hazard ratio=2.11, 95% CI=1.00-4.47; P=0.05). However, in the multivariate competing risks Cox model, donor-recipient age difference was not associated with increased patient death, death-censored graft failure or serum creatinine at 5 or 10 years, nor was it associated with increased risk of acute rejection within the first 6 months. Conclusions. Recipients of kidney transplants donated by live donors who are significantly older than recipients have similar graft and patient survivals to recipients from organs of similar vintage. Thus, living kidney donors, who are up to 30 years older than their recipients, provide kidneys of excellent quality. These findings are of relevance when considering paired kidney donation programme because the chance of finding a suitable match should not be unnecessarily limited by unjustified restrictions on the perceived disadvantage of high donor-recipient age difference.