Are the equations for the creatinine-based estimated glomerular filtration rate applicable to the evaluation of renal function in Japanese children and adult patients receiving chemotherapy?

Abstract

Equations for the creatinine-based estimated glomerular filtration rate (eGFR) were recently established for Japanese adults (>18 years old) and children (2-11 years old), respectively, but it is unclear whether eGFR can be as useful as 24-h creatinine clearance (CCr) for assessing renal function in patients receiving chemotherapy. This study examined the degree of concordance between eGFR and CCr and the risk factors leading to the overestimation of renal function by eGFR. A total of 53 data points of 19 children and 56 data points of 16 adults who received chemotherapy were analyzed retrospectively. Body mass index, serum creatinine concentration, 24-h urinary creatinine excretion (UCr), and nephrectomy were considered as risk factors for overestimation by eGFR. In the pediatric part of the study, 7 data points from 3 patients who underwent nephrectomy were included. The eGFR in patients with bilateral kidneys overestimated renal function to a greater degree than in patients with a unilateral kidney. In 45.7 % of pediatric patients with bilateral kidneys and in 19.6 % of adult patients, eGFR overestimated renal function. The risk factor for overestimation was lower UCr in pediatric patients with bilateral kidneys and adult patients. Concordance between eGFR and CCr in pediatric patients with a unilateral kidney should be assessed separately from that in patients with bilateral kidneys. In restricting calculation of eGFR to pediatric patients with bilateral kidneys and adult patients without little muscle mass, eGFR may be useful regardless of whether patients are receiving chemotherapy.