Creatinine-based glomerular filtration rate estimation in patients with liver disease: the new Chronic Kidney Disease Epidemiology Collaboration equation is not better

Objectives Limitations of serum creatinine in patients with an impaired liver function are well known. The commonly used modification of diet in renal disease (MDRD) equation has a low diagnostic performance to approximate kidney function in patients after liver transplantation (LT) and patients with liver cirrhosis (LC). The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula has been shown to provide a more accurate estimation of kidney function in patients with chronic kidney disease, but studies in patients with liver disease are lacking. Methods We evaluated the diagnostic performance of CKD-EPI in comparison with the re-expressed MDRD formula in patients after LT (group 1; n = 59) and in patients suffering from LC (group 2; n = 44). GFR was measured by Tc-99m-diethylenetriamine penta-acetic acid (group 1) and inulin clearance (group 2). Bias, precision, and accuracy as compared with the measured GFR were determined. Results The measured mean GFR (95% confidence interval) was 52.3 ml/min/1.73m(2) (47.7; 56.9; group 1) and 35.3 ml/min/1.73m(2) (29.12; 41.3; group 2), respectively. In transplanted patients GFR estimation by CKD-EPI and MDRD did not significantly differ with respect to bias (9.7 vs. 4.3 ml/min/1.73m(2)), precision (16.9 vs. 15.5 ml/min/1.73m(2)) and accuracy (64.4 vs. 69.5% within 30% of 'true GFR'). In patients with LC, both formulae showed a very high bias (42.5 vs. 40.1 ml/min/1.73m(2)), a very low precision (20.7 vs. 25.7 ml/min/1.73m(2)) and accuracy (6.8 within 30% of the measured GFR in both groups). Conclusion The CKD-EPI equation does not improve the creatinine-based GFR estimation in patients after LT. In patients with LC, both equations should not be applied as they extremely overestimate GFR. Eur J Gastroenterol Hepatol 23:969-973 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.