title: Creatinine-based glomerular filtration rate estimation in patients with liver disease:  the new Chronic Kidney Disease Epidemiology Collaboration equation is not better.
abstract: OBJECTIVE
  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 99mTc-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/1.73 m2 (47.7; 56.9; group 1) and 35.3 ml/min/1.73 m2 (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/1.73 m2), precision (16.9 vs. 15.5 ml/min/1.73 m2) 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/1.73 m2), a very low precision (20.7 vs. 25.7 ml/min/1.73 m2) and accuracy (6.8 within 30% of the measured GFR in both groups).
  
  
  CONCLUSIONS
  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.
authors: Department of Internal Medicine, University of Bonn, Bonn, Germany. tm.gerhardt@web.de
authors: Thomas
authors: T
authors: Gerhardt
authors: Uwe
authors: U
authors: Pöge
authors: Birgit
authors: B
authors: Stoffel-Wagner
authors: Holger
authors: H
authors: Palmedo
authors: Tilman
authors: T
authors: Sauerbruch
authors: Rainer Peter
authors: RP
authors: Woitas
mesh_terms: D000328:Adult; D000465:Algorithms; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D008103:Liver Cirrhosis / Q000097:blood / Q000503:physiopathology*; D016031:Liver Transplantation; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate
chemical_list: D015415:Biomarkers; D019275:Radiopharmaceuticals; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate