Comparison of cystatin C and creatinine-based glomerular filtration rate formulas with 51Cr-EDTA clearance in patients with cirrhosis.
OBJECTIVE
Renal function is an important predictor of survival in cirrhosis and liver transplantation. GFR estimates using serum cystatin C (CysC) are proposed as better predictors of renal function than ones on the basis of serum creatinine (Cr). Our aims were: (1) evaluate correlations between serum CysC and different methods of creatinine measurements; (2) compare CysC and Cr GFR formulas with (51)Cr-EDTA; and (3) evaluate liver-related parameters potentially influencing GFR.


METHODS
254 blood samples in 65 patients with cirrhosis correlating CysC with four Cr methods were used; another 74 patients comparing (51)Cr-EDTA GFR to Modification of Diet in Renal Disease and Larsson and Hoek formulas for CysC were also included. Agreement was assessed using Bland-Altman plots and concordance correlation coefficients. Multivariate linear regression analysis was used for GFR predictors.


RESULTS
Serum CysC correlated modestly with O'Leary modified Jaffe, compensated kinetic Jaffe, enzymatic creatinine, and standard kinetic Jaffe 0.72/0.71/0.72/0.72 (all P < 0.001). Bland-Altman agreement with (51)Cr-EDTA GFR was poor; the best agreement was Modification of Diet in Renal Disease (concordance 0.61; 95% CI, 0.47 to 0.71); the worst agreement was the Hoek formula (concordance 0.46; 95% CI, 0.27 to 0.61). A new GFR formula including the Child-Pugh score improved the accuracy of Cr GFR formulas compared with (51)Cr-EDTA GFR.


CONCLUSIONS
Estimated GFR in cirrhosis is not better with CysC formulas compared with creatinine ones: specific formulas may be necessary.
Xirouchakis
Elias
E
The Royal Free Sheila Sherlock Liver Centre and University Department of Surgery, Royal Free Hospital and University College London, London, United Kingdom.
Marelli
Laura
L
Cholongitas
Evangelos
E
Manousou
Pinelopi
P
Calvaruso
Vincenza
V
Pleguezuelo
Maria
M
Guerrini
Gian Piero
GP
Maimone
Sergio
S
Kerry
Andrew
A
Hajjawi
Mark
M
Nair
Devaki
D
Thomas
Michael
M
Patch
David
D
Burroughs
Andrew Kenneth
AK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001663:Bilirubin / Q000097:blood; D002860:Chromium Radioisotopes; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D004492:Edetic Acid; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008103:Liver Cirrhosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis
D002860:Chromium Radioisotopes; D055316:Cystatin C; D004492:Edetic Acid; D003404:Creatinine; D001663:Bilirubin