title: The chronic kidney disease epidemiology collaboration equation combining creatinine and cystatin C accurately assesses renal function in patients with cirrhosis.
abstract: BACKGROUND
  Accurate measurement of renal function in cirrhotic patients is still challenging. To find the best test for the determination of the true glomerular filtration rate (GFR) in cirrhotic patients this study prospectively compared measured (m)GFR, the gold standard, with estimated (e)GFR using equations based on serum levels of creatinine and cystatin C.
  
  
  METHODS
  GFR was measured by sinistrin clearance using the bolus method in 50 patients with cirrhosis (Child Turcotte Pugh score A, B and C) and 24 age-matched healthy subjects as controls. Measured (m)GFR was compared to eGFR using bias, accuracy 10 % and 30 %, as well as correlation coefficients.
  
  
  RESULTS
  Creatinine-based equations generally overestimated GFR in patients with cirrhosis and showed a bias (average difference between mGFR and eGFR) of -40 (CG), -12 (MDRD) and -9 (CKD-EPI-Cr) ml/min/1.73 m(2). Cystatin C-based equations underestimated GFR, especially in patients with Child Turcotte Pugh score C (bias 17 ml/min/1.73 m(2)for CKD-EPI-CysC). Of these equations, the CKD-EPI equation that combines creatinine and cystatin C (CKD-EPI-Cr-CysC) showed a bias of 0.12 ml/min/1.73 m(2) as compared to measured GFR.
  
  
  CONCLUSIONS
  The CKD-EPI equation that combines serum creatinine and cystatin C measurements shows the best performance for accurate estimation of GFR in cirrhosis, especially at advanced stages.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. elisabeth.krones@medunigraz.at.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Krones
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. peter.fickert@medunigraz.at.
authors.forename: Peter
authors.initials: P
authors.lastname: Fickert
authors.affiliation: Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. sabine.zitta@medunigraz.at.
authors.forename: Sabine
authors.initials: S
authors.lastname: Zitta
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. stefanneunherz@gmail.com.|Department of Cardiology, Klinikum Leverkusen, Leverkusen, Germany. stefanneunherz@gmail.com.
authors.forename: Stefan
authors.initials: S
authors.lastname: Neunherz
authors.affiliation: Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. katharina.artinger@medunigraz.at.
authors.forename: Katharina
authors.initials: K
authors.lastname: Artinger
authors.affiliation: Institute for Physiological Chemistry, Medical University of Graz, Graz, Austria. gilbert.reibnegger@medunigraz.at.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Reibnegger
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. franziska.durchschein@medunigraz.at.
authors.forename: Franziska
authors.initials: F
authors.lastname: Durchschein
authors.affiliation: Division for General Surgery, Department of Surgery, Medical University of Graz, Graz, Austria. doris.wagner@medunigraz.at.
authors.forename: Doris
authors.initials: D
authors.lastname: Wagner
authors.affiliation: Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria. tatjana.stojakovic@medunigraz.at.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Stojakovic
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. vanessa.stadlbauer@medunigraz.at.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Stadlbauer
authors.affiliation: Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria. guenter.fauler@medunigraz.at.
authors.forename: Günter
authors.initials: G
authors.lastname: Fauler
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. rudolf.stauber@medunigraz.at.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Stauber
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. gernot.zollner@medunigraz.at.
authors.forename: Gernot
authors.initials: G
authors.lastname: Zollner
authors.affiliation: Department of Surgery, Division of Transplant Surgery, Medical University of Graz, Graz, Austria. daniela.kniepeiss@medunigraz.at.
authors.forename: Daniela
authors.initials: D
authors.lastname: Kniepeiss
authors.affiliation: Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria. alexander.rosenkranz@medunigraz.at.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Rosenkranz
mesh_terms: D000328:Adult; D000368:Aged; D001317:Austria / Q000453:epidemiology; D015415:Biomarkers; D015897:Comorbidity; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D015340:Epidemiologic Research Design; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine