Plasma cystatin C as a marker of renal function in patients with liver cirrhosis.
Cystatin C is a low molecular weight protein and the plasma level of cystatin C is mainly determined by glomerular filtration, making cystatin C an endogenous marker of glomerular filtration rate. The aim of the study was to elucidate the applicability of plasma cystatin C as a marker of renal function in patients with liver cirrhosis. Serum cystatin C and creatinine concentrations were compared with creatinine clearance. Thirty-six patients (14 females and 22 males aged between 33 and 81 years) with liver cirrhosis with normal to severely impaired kidney function were included. Plasma cystatin C was measured by an automated particle-enhanced nephelometric immunoassay (Dade Behring Diagnostics) and plasma creatinine by an enzymatic method. Plasma levels of cystatin C and creatinine were found to increase with decreasing values of creatinine clearance. The reciprocal values of cystatin C and creatinine were compared with those for creatinine clearance revealing an r2 of 0.37 and 0.18, respectively. Comparison of the areas under the curves (AUC) of the non-parametric receiver-operating characteristic plots for plasma cystatin C (AUC=0.7364; SE=0.0929) and plasma creatinine (AUC=0.6309: SF=0.1028) revealed a significant difference between plasma cystatin C and plasma levels of creatinine (p-value=0.03). The results demonstrate that the diagnostic accuracy of plasma cystatin C was better than plasma creatinine in identifying liver cirrhotic patients with reduced glomerular filtration rate.
Randers
E
E
Department of Internal Medicine, Viborg-Kjellerup County Hospital, Viborg, Denmark. elseranders@sol.dk
Ivarsen
P
P
Erlandsen
E J
EJ
Hansen
E F
EF
Aagaard
N K
NK
Bendtsen
F
F
Vilstrup
H
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D015415:Biomarkers; D003404:Creatinine / Q000097:blood; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000502:physiology*; D007677:Kidney Function Tests / Q000379:methods; D008103:Liver Cirrhosis / Q000097:blood*; D008297:Male; D008875:Middle Aged; D051437:Renal Insufficiency / Q000097:blood* / Q000175:diagnosis*
D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D003404:Creatinine