Total and Free Serum Sialic Acid Concentration in Liver Diseases

Background. The objective of this study was to compare the levels of total (TSA) and free (FSA) sialic acid in acute and chronic liver diseases. Materials and Methods. The serum TSA and FSA levels were determined in 278 patients suffering from acute and chronic liver diseases of different etiologies. TSA was estimated by enzymatic method and FSA by the thiobarbituric method modified by Skoza and Mohos. Results. There were no significant differences in the serum TSA concentration between liver diseases of different etiologies, although in most of the liver diseases the mean TSA level was significantly lower than that in the control group. In contrast to TSA, the concentration of FSA appears to differ between liver diseases. In toxic hepatitis it was higher than that in nonalcoholic cirrhosis. However, neither of them differs between alcoholic and nonalcoholic cirrhosis or between liver tumors and tumors with cirrhosis. Conclusions. We conclude that the changes in concentrations of TSA and FSA during the same liver diseases indicate significant disturbances in sialylation of serum glycoproteins.