S protein/vitronectin in chronic liver diseases: correlations with serum cholinesterase, coagulation factor X and complement component C3

S protein/vitronectin plays an important role as a regulatory component in the terminal steps of the complement- and coagulation cascades. In patients suffering from chronic liver diseases, plasma S protein concentration was measured and compared with changes in serum cholinesterase activity, coagulation factor X activity and complement component C3 concentration. Significant decreases of all these proteins were seen in liver cirrhosis. Changes in S protein concentration correlated closely with those of cholinesterase, factor X and complement C3. The data give support for the liver as the main organ of plasma S protein/vitronectin synthesis.