Comparison of GFR Determined by Using Serum Cystatin C and Serum Creatinine Concentration Alone and in Combination for Diagnosis of Hepatorenal Syndrome

Introduction: Renal dysfunction is common in patients with liver cirrhosis, occurs about 19% of hospitalized patients with cirrhosis which have a huge impact on prognosis. Serum creatinine (Cr) is a widely used but less reliable marker to estimate glomerular filtration rate (GFR). Serum cystatin C(CysC) is a good endogenous marker to determine early renal impairment. Combined cystatin C and creatinine is an effective reflection of GFR. This study aimed to validate renal function by estimation of GFR using serum cystatin C and serum creatinine individually and combinedly. Methods: This was an observational cross sectional study, conducted in Department of Hepatology, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh. Thirty patients were cirrhosis with hepatorenal syndrome (HRS) and thirty were cirrhosis without HRS.

Results: Mean value of serum creatinine, serum cystatin C, GFR by creatinine, GFR by cystatin C and GFR by (cre-cys) were statistically significant (p<0.05) between two groups. All the study population were in Child Pugh B and C. Association of mean values of creatinine, cystatin C, GFR by creatinine, GFR by cystatin C and GFR by (cre-cys) with Child Pugh B and C were statistically significant in both groups. Based on ROC curves at cut-off value of 1.29 mg/ml cystatin C had sensitivity 96.7% and specificity 76.7% for detecting HRS. Coefficient of GFR by creatinine was -0.01 (CI -0.01 to 0.00) which was not statistically significant. Coefficient of GFR by cystatin C was -0.02 (CI -0.03 to 0.00) and GFR by (cre-cys) was 0.04 (CI 0.01 to 0.06) which were statistically significant for diagnosis of HRS.

Conclusion: Combined serum creatinine and cystatin C based GFR showed significant association to discriminate early renal impairment in patients with cirrhosis of liver.