Risk factors for renal allograft survival from older cadaver donors

The shortage of cadaver donors for kidney transplantation has prompted many centers to use kidneys from older donors. The use of older donor kidneys has been associated with lower graft survival.

United Network for Organ Sharing data of all adult cadaveric renal transplant recipients receiving kidneys from adult donors between 1988 and 1994 (transplants, n=35,621) were analyzed to further study this issue. All patients were followed for a minimum of 1 year after transplantation. The recipients were classified according to donor age: group 1, 19-50 years; group 2, 51-60 years; and group 3, >60 years.

The actuarial kidney survival estimates for group 1: (n=27,999) at 1, 3, and 5 years were 82.7%, 72.2%, and 61.4%. The corresponding values for group 2 (n=5,367) and group 3 (n=2,255) were 77.3%, 63.3%, and 51.3%; and 71.7%, 55.3%, and 42.7%, respectively (P<0.0001). Logistic regression analysis for 1-year graft survival was performed, and odds ratios (ORs) were computed for various risk factors. Increased odds of graft failure were seen with increasing donor age, previous transplantation, and elevated panel-reactive antibody. In the older donor group, lower ORs were observed if the recipients were Hispanic or Asian. In addition, kidneys from African-American or Asian donors had a poorer graft outcome. A similar analysis for 3-year graft survival for those grafts functioning at 1 year revealed poorer survival with older African-American donors (OR=1.78, P<0.02), whereas improved survival rates were seen when older kidneys were used for older (OR=0.635, P<0.01) and female (OR=0.733, P < 0.01) recipients. Statistically significant factors such as HLA mismatch, cold ischemia time, and African-American or diabetic recipients differ in their impact on graft survival across the donor age groups.

In conclusion, kidneys from older donors are associated with poorer graft survival rates with African-American and Asian donors and African-American recipients, and no detrimental effects when used for older, Hispanic, Asian, or female recipients.