Metabolic demand and renal mass supply affecting the early graft function after living donor kidney transplantation.

BACKGROUND: Graft mass has been demonstrated to be a determinant of outcome after kidney transplantation. An insufficient nephron might fail to meet the metabolic demands of the recipient and lead to hyperfiltration.
METHODS: The study population was restricted to live donor transplants demonstrating immediate function that had neither ischemic injury, episodes of rejection, nor any complications that resulted in a functional decrease of the graft. The donated kidney was weighed just after cold flush, and the recipient's serum creatinine (Scr) was measured on a daily basis postoperatively. When the recipient's Scr reached the baseline, the recipient's 24-hour urine was collected for the amount of proteinuria (Upr), creatinine excretion (Ucr), and creatinine clearance (Ccr) calculation. As the parameters of the metabolic demands of donor and recipient, body weight, height, body surface area, lean body weight, and body mass index were noted. Pearson correlation and linear regression were carried out.
RESULTS: The graft function, as measured by Scr, Ucr, and Upr, was not directly correlated with the graft weight but rather correlated with the ratios of graft weight to the parameters of recipient's metabolic demands. As recipient size increased, the metabolic demand has increased. The parameters of recipient's metabolic demands were directly correlated with Scr and Ucr, rather than with Upr.
CONCLUSION: During living donor and recipient matching, both the potential sizes of the donated kidney and the recipient should be considered in terms of the early graft function after transplantation.