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.