Serum laminin--its concentration increases with portal hypertension in cirrhotic liver disease.

The concentrations in serum of the high molecular weight glycoprotein laminin and of the N-terminal propeptide of type III procollagen were determined in various histologically proven fibrotic liver diseases (n = 33), of which the portal venous pressure has been measured indirectly. The concentrations of both biomatrix proteins were related to the portal venous pressure. Laminin in serum of normal persons (n = 146) ranged from 0.81 to 1.43 U/ml. Compared with the mean normal concentration (1.04 U/ml) the glycoprotein is increased in fibrotic liver lesions in parallel with the severity of the fibrotic organ transformation reaching the highest values (2.58 +/- 0.87 U/ml, P less than 0.001) in liver cirrhosis (n = 12). The level of N-terminal propeptide of type III procollagen increased similarly, but the concentrations of both matrix proteins exhibit only weak statistical correlations (r = 0.6680). The level of laminin is correlated strongly with the elevation of the portal venous pressure in cirrhotic (r = 0.9206) and fibrotic (r = 0.7157) subjects. For the propeptide of procollagen the respective correlation is r = 0.4808. Molecular sieve chromatography reveals a heterogeneous composition of laminin-related antigens in serum with two main molecular weight fractions of 700 and 300 kD, respectively.