Comparison Between CKD-EPI Creatinine and MDRD Equations to Estimate Glomerular Filtration Rate in Kidney Transplant Patients.

Background. The Modification of Diet in Renal Disease (MDRD) equation is widely used to estimate glomerular filtration rate (eGFR) in kidney transplant (KT) patients. The novel Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI) could improve accuracy of GFR estimation. Our aim was to compare both equations for staging of CKD in KT patients. Methods. In a cohort of KT patients, correlation of eGFR according to MDRD and CKD-EPI with 24-hour creatinine clearance (24h-CrCl) was evaluated. Concordance between both equations for CKD staging was performed. MDRD was used for initial CKD staging. The mean difference of GFR between 24h-CrCl and each equation was calculated and Bland-Altman analysis applied. Results. A cohort of 463 KT patients were studied: 67% female, overall average age 46 14 years, 41% living donor, mean time of transplantation 71 months (3-95), and mean serum creatinine 1.68 +/- 1.03 mg/dL. For the whole cohort (all CKD stages), eGFR by CKD-EPI was 5.33 mL/min/1.73 m(2) higher than by MDRD (P < .01). For CKD stages 1, 2, and 3A, the mean eGFR differences (CKD-EPI MDRD) were 13.98 +/- 3.27, 8.2 +/- 1.98, and 5.34 +/- 1.32 mL/min/1,73 m(2), respectively. The percentage of patients with eGFR <60 mL/min/1.73 m(2) decreased from 63.8% according to MDRD to 53.9% with the use of CKD-EPI. In women and patients <= 65 years old, eGFR by CKD-EPI was 5.98 and 5.81 mL/min/1.73 m(2) higher, respectively, than by MDRD (P < .01). Conclusions. The novel CKD-EPI reduces the number of patients with eGFR <60 mL/min/1.73 m(2) and consequently assigns lower CKD stages to our KT population.