GFR was estimated with the Modification of Diet in Renal Disease ( MDRD ) equation and the Chronic Kidney Disease Epidemiology Collaboration study eGFR ( CKD-EPI-Creat ) in 257 donors and the two newly developed equations using CysC with and without Creat , eGFR ( CKD-EPI-CysC ) and eGFR ( CKD-EPI-Creat + CysC ) , in 215 donors .