Serum cystatin C: a non-invasive marker of liver fibrosis or of current liver fibrogenesis in chronic hepatitis C?

Abstract

Background. Serum levels of cystatin C, an endogenous inhibitor of cysteine proteases, provide an alternative method to creatinine-based criteria for measuring glomerular filtration rate. Preliminary data suggested that serum cystatin C levels parallel with the stage of liver fibrosis in chronic liver disorders. Our aim has been to evaluate the possible role of serum cystatin C as a marker of liver fibrosis in hepatitis C virus (HCV)-induced chronic liver disease. Material and methods. 100 consecutive patients (56 men, mean age 51.2 ± 9.5 yrs) with HCV-induced chronic liver disease, scheduled for their first liver biopsy and naive for antiviral therapy were included. Liver fibrosis was evaluated with the METAVIR score. Serum cystatin C and standard laboratory tests were measured simultaneously. Patients with ethanol abuse (> 50 g/day), HBV or HIV coinfection or plasma creatinine ≥ 1.20 mg/dL were excluded. In addition, a second group of 16 patients fulfilling the same requisites and diagnosed with HCV-induced compensated cirrhosis by clinical evidence of portal hypertension was included. Results. Serum cystatin C levels significantly increase from F0 to F2 fibrosis stages, remained stable in F3 and F4 stages and increased again in the group of non-biopsied compensated cirrhosis. Serum cystatin C levels were higher in patients with moderate-advanced necroinflammation in the liver biopsy. Conclusion. Serum cystatin C level may reflect current fibrogenic and necroinflammatory activities in chronic HCV-induced liver disease with normal renal function but can not be considered as a non-invasive marker of liver fibrosis.