Impact of donor recipient size matching on outcomes in renal transplantation

Interest in nonimmunologic factors affecting longterm graft survival has focused on adequacy of nephron dosing. Body surface area (BSA) is a reliable surrogate for nephron mass, In a retrospective study of 378 primary recipients of paired kidneys from 189 cadaveric donors, we assessed the impact of matching donor and recipient BSA on outcome over 7 years, BSA of donors was 1.82+/-0.26 m(2), Initially, paired recipients of kidneys from a single donor were divided into two groups. Group 1 included the recipient with the larger BSA of the pair (1.97+/-0.17 m(2)), while group 2 consisted of smaller BSA recipients (1.69+/-0.19 m(2)), Although early function was better in group 2 patients, graft survival at 1 year (77% vs. 79%) and 5 years (54% vs. 55%) was identical between groups, as were most recent serum creatinine levels (2.0+/-0.1 vs. 2.1+/-0.2 mg/dl). A second analysis divided patients with a functioning allograft at discharge from initial transplant hospitalization (n=345) into three groups based solely on donor to recipient BSA ratio: the ratio of group A (n=39) was less than or equal to 0.8, that of group B (n=255) was between 0.81 and 1.19, and that of group C (n=51) was greater than or equal to 1.2. Graft survival and kidney function over 5 years did not differ among groups. In multivariate analysis of 17 variables, donor:recipient ESA, independent of other risk factors, did not affect risk of allograft loss. These data indicate that including nephron mass as a criterion for cadaveric organ allocation is unlikely to improve long-term results in renal transplantation.