Lipid-bound sialic acid (LSA) in liver diseases of different etiologies.

OBJECTIVE There are evidences that the changes in glycosylation and sialylation of proteins and lipids play an important role in the pathogenesis and progression of various liver diseases. The aim of this study was to evaluate the changes in the sialylation of serum lipids measured by the level of lipid-bound sialic acid (LSA) in liver diseases of different etiologies. MATERIALS AND METHODS Tested group consisted of 303 patients suffering from liver diseases: alcoholic and non-alcoholic cirrhosis, chronic non-viral hepatitis, toxic hepatitis, chronic viral C and B hepatitis, autoimmune hepatitis, primary liver cancer, liver cancer and cirrhosis (mixed group), acute hepatitis B, primary biliary cirrhosis and fatty liver. LSA was determined by the method of Katopodis and co-workers. RESULTS There were significant differences in the serum LSA concentrations between liver diseases of different etiologies. The level of LSA in liver tumors was higher than that in both types of cirrhosis: alcoholic and non-alcoholic. In turn, LSA level in non-alcoholic cirrhosis was lower than in toxic hepatitis and mixed group. There was no difference in LSA concentration between tumor and mixed group. Similarly to LSA, AFP level in tumor group was also higher than that in both cirrhotic groups, but there was no difference in AFP concentration between tumor and mixed group. CONCLUSIONS The sialylation of serum lipids alters in liver diseases of different etiologies. Given the importance of glycans in biological systems we can speculate that the changes in lipids sialylation play an important role in liver pathology, especially in primary cancer, cirrhosis and toxic hepatitis.