Investigation of the factors associated with circulating soluble CD36 levels in patients with HCV-related chronic liver disease

BACKGROUND CD36, a class B scavenger receptor, participates in the pathogenesis of metabolic dysregulation such as insulin resistance, hepatic steatosis, and atherosclerosis. Persistent hepatitis C virus (HCV) infection often evokes these metabolic abnormalities. The primary purpose of this study was to investigate the role of CD36 in the pathogenesis of insulin resistance and hepatic steatosis caused by chronic HCV infection. METHODS Forty-five patients with HCV-related chronic liver disease (CLD-C) were enrolled in this study. CD36 expression in the liver specimen was examined by an immunohistochemical procedure. The concentrations of circulating soluble form of CD36 (sCD36) and oxLDL were determined by the enzyme-linked innunosorbent assay. Insulin resistance was estimated by the values of HOMA-IR. RESULTS Moderate to extensive hepatic CD36 expression was observed in the sinusoids of all enrolled CLD-C patients. CD36-positive sinusoids appeared to be identical to Kupffer cells. The severity of CD36 expression in the hepatic sinusoids was significantly correlated with the sCD36 level in sera of patients with CLD-C. The serum sCD36 levels were significantly correlated with body mass index and serum oxLDL levels in those patients. However, the serum sCD36 concentrations were independent of the values of HOMA-IR and the severity of hepatic steatosis. CONCLUSIONS These data suggest that the serum sCD36 levels reflect the severity of CD36 expression on the Kupffer cells in patients with CLD-C, and that the serum sCD36 levels were associated with obesity, although the levels were independent of insulin resistance and hepatic steatosis in those patients.