Clinical Accuracy of Average Creatinine and Cystatin-C-Based Estimated GFR in Japanese Living Renal Transplantation Donors

Abstract

Objective: To evaluate the clinical accuracy of several estimated glomerular filtration rates (eGFR) using cystatin-C to measure renal function in Japanese renal donors.

Methods: In total, 61 healthy, potential renal donors were assessed. The average age was 42.7 years (range: 27-67). We evaluated the GFR based on the 24-hour creatinine clearance (Ccr) using 24-hour urine collection, eGFR based on serum creatinine (eGFRcr), and cystatin-C (eGFRcys) levels using an equation developed by the Japanese Society of Nephrology, the average of the eGFRcr and eGFRcys (eGFRave) rates, and an eGFR based on a combination of serum creatinine and cystatin-C values using an equation developed by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI). The association between Ccr and each eGFR was evaluated using Pearson's r and the Bland-Altman plot.

Results: Pearson's correlation coefficient analysis revealed a significant correlation between the Ccr and the eGFRcr (r = 0.62, P < .0001), eGFRave (r = 45, P = .0003), and eGFRcr-cys (r = 0.451, P = .0014). The Bland-Altman study suggested that each eGFR had a low level of agreement with the Ccr because the latter was higher than each eGFR. On the other hand, the eGFRave had the highest level of agreement with CCr × 0.715.

Conclusions: The eGFRave may provide a simple and useful method of evaluating renal function in living renal transplant donors.