Role of cystatin C and renal resistive index in assessment of renal function in patients with liver cirrhosis

AIM: To evaluate the clinical significance of cystatin C and renal resistive index for the determination of renal function in patients with liver cirrhosis. METHODS: We conducted a study of 63 patients with liver cirrhosis. A control group comprised of 30 age and gender-matched healthy persons. Serum cystatin C was determined in all study subjects and renal Doppler ultrasonography was made. Estimated glomerular filtration rate from serum creatinine (GFR(Cr)) and cystatin C (GFR(Cys)) was calculated. RESULTS: We confirmed significant differences in values of cystatin C between patients with different stages of liver cirrhosis according to Child-Pugh (P = 0.01), and a significant correlation with model of end stage liver disease (MELD) score (r(s) = 0.527, P lt 0.001). More patients with decreased glomerular filtration rate were identified based on GFR(Cys) than on GFR(Cr) (P lt 0.001). Significantly higher renal resistive index was noted in Child-Pugh C than in A (P lt 0.001) and B stage (P = 0.001). Also, a significant correlation between renal resistive index and MELD score was observed (r(s) = 0.607, P lt 0.001). Renal resistive index correlated significantly with cystatin C (r(s) = 0.283, P = 0.028) and showed a negative correlation with GFR(Cys) (r(s) = -0.31, P = 0.016). CONCLUSION: Cystatin C may be a more reliable marker for assessment of liver insufficiency. Additionally, cystatin C and renal resistive index represent sensitive indicators of renal dysfunction in patients with liver cirrhosis.