Donor-recipient age matching improves years of graft function in deceased-donor kidney transplantation

Background. Donor and recipient age in kidney transplantation are known to affect graft and patient survival. In deceased-donor (DD) transplantation, donor and recipient age matching are being increasingly accepted as part of the kidney allocation programme. The aims of this study are to evaluate the effect of donor and recipient age on transplant outcomes and to determine the effect of changing existing allocation criteria to allocation based on age matching of donors and recipients on total graft years of function.Methods. Using the Australia and New Zealand Dialysis and Transplant Registry, all DD kidney transplant recipients in Australia and New Zealand between 1991 and 2006 were analysed (n = 4616). Outcomes analysed were overall graft failure, death with functioning graft and serum creatinine. We calculated the mean time to graft loss ('years of graft function') for donor and recipient age cut-offs as 60 and 55 years, respectively, over up to 16 years follow-up. We then examined the gain in graft years if all older kidneys were allocated to older recipients.Results. Older donors were associated with higher risk of overall graft failure [adjusted hazard ratio (HR) = 1.79, 95% confidence interval (95% CI) = 1.45, 2.21 and HR = 1.29, 95% CI = 1.09, 1.53, respectively] at 1-8 years post-transplant and higher serum creatinine at 1 and 5 years post-transplant (mean differences 32.74 μmol/L, 95% CI 27.60, 37.89 and 38.17 μmol/L, 95% CI 27.58, 48.77, respectively). Overall, young and old recipients with young donor kidneys have an additional two to three mean graft years compared to those receiving older donor kidneys.Conclusion. Donor and recipient age matching is an effective method of organ allocation to improve total graft years.