Outcomes of transplantation using kidneys from donors meeting expanded criteria in Australia and New Zealand, 1991 to 2005.

BACKGROUND: Kidneys from expanded criteria donors (ECD) are reported to have inferior transplant outcomes.
METHODS: Using the Australia and New Zealand Dialysis and Transplant Registry, we reviewed deceased donor kidneys transplanted from 1991 to 2005 in Australia and New Zealand, followed until December 2006. ECD was defined using United Network for Organ Sharing criteria. Graft and patient outcomes, estimated glomerular filtration rates (eGFR), acute rejection, and delayed graft function were analyzed by donor-age and ECD status, with adjustment for important covariates.
RESULTS: There were 3248 recipients of non-ECD kidneys and 781 recipients of ECD kidneys. Compared with donors aged less than 50 years, adjusted hazard ratios for graft failure (GF) at 0 to 1 and 1 to 5 years for ECD kidneys from donors aged 60 years or above were 1.92 (1.48-2.49; P<0.001) and 2.52 (1.97-3.23; P<0.001). The hazard ratios for GF were 1.87 (1.31-2.70; P<0.05) for ECD kidneys from donors aged 50 to 59 years in the first year but were not increased subsequently. Mean eGFR at 1 year decreased with increasing donor age and ECD status (56.4 [53.8-58.9] mL/min for kidneys from donors aged <50, 46.6 [45.0-48.3] and 43.5 [41.1-45.9] for non-ECD and ECD donors aged 50 to 59 years, respectively, and 38.6 [36.9-40.4] for donors > or =60; P<0.001) but subsequent eGFR loss was similar except for donors aged 60 years or above (P=0.021). Acute rejection and delayed graft function were more frequent in ECD kidney recipients, but the associations between GF and donor age/ECD status were independent of these factors.
CONCLUSIONS: For recipients of ECD kidneys, donor age 60 years or above is the most significant determinant of poor outcome; donor age 50 to 59 years represents a category of intermediate risk.