Evaluation of MDRD4, CKD-EPI, BIS-1, and modified Cockcroft-Gault equations to estimate glomerular filtration rate in the elderly renal-transplanted recipients.

Equations to estimate glomerular filtration rate (eGFR) were developed in patients using the variables age, body weight, and serum creatinine, which may be different in the elderly. Elderly renal transplant patients (EG; n=70; mean age 65 ± 4 y) who measured plasma Cr-EDTA-Clearance (mGFR) had mGFR compared to eGFR obtained by the Cockcroft-Gault corrected by body surface area (CG-BSA), the modification of diet in renal disease (MDRD-4), the Berlin Initiative Study (BIS-1), and the chronic kidney disease epidemiology collaboration (CKD-EPI). Results were validated using a cohort of 43, of the 70 elderly recipients, who performed a second Cr-EDTA-Clearance. Mean mGFR was 47 ± 16 mL/min/1.73 m and statistically lower than eGFR by MDRD (52 ± 19, P=.001) and BIS-1 (51 ± 13, P=.007) but not different from the CG-BSA (47 ± 15) and CKD-EPI (49 ± 18). The CKD-EPI and CG-BSA presented the lowest bias but only CKD-EPI also showed the highest 30% and 10% accuracy. The same findings were repeated in the validation set. For a cohort of elderly recipients ≥65 years (n=35, 68 ± 3y), the CKD-EPI performed better with the lowest bias (0 ± 12 mL/min/1.73 m ) and best 30% and 10% accuracy. The CKD-EPI equation is a valuable tool to monitor GFR in the elderly RTx recipients.