Fractional Creatinine Clearance of the Donated Kidney As a Predictor of Graft Function after Living Donor Transplantation

Abstract

Purpose: An insufficient functioning nephron mass might fail to meet the metabolic demands of the recipient and lead to hyperfiltration. This hyperfiltration damage also increase allograft failure rates. During the preoperative evaluation of a potential kidney donor, it is important to estimate the renal function of donated kidney compared with the metabolic needs of the recipient.

Methods: The functional ratio of each kidney was measured using technetium-99m diethylenetriaminepentaacetic acid. The serum creatinine (Scr, mg/dL) and estimated creatinine clearance (Ccr, mL/min/1.73m2) using the Cockcroft-Gault formula were measured and calculated in 82 donors. We excluded recipients who had an episode of rejection, and followed all recipients for more than 12 months posttransplantation.

Results: The average functional proportion of the donated kidney was 50.5%+/-4.7% of the total Ccr 83.4+/-18.3 of donors. The Scr of recipients at 1,3,6 and 9months posttransplantation were significantly (P<.05) correlated with the fractional Ccr of thedonated kidney; however Scr at 1 year was not correlated (P=.307). Furth-ermore the Ccr of the recipient at 1, 3, and 6months post transplantation were significantly (P<.05) correlated with fractional Ccr ofthe donated kidney; however the Ccr at 9months and 1 year were not correlated (P=.094 and.141, respectively).

Conclusion: The Scr and Ccr of recipients within 6 months after transplantation may depend on the functional mass of the donated kidney, which should be estimated prior to kidney donation and compared with the metabolic demands of the potential recipient.