The predictive value of serum laminin for portal hypertension in chronic liver diseases.

The concentration of laminin, a high molecular weight basement membrane glycoprotein, was determined with a competitive radioimmunoassay in serum from the hepatic and cubital veins of patients with chronic liver diseases (n = 175), and correlated with portal venous pressure calculated from the hepatic vein pressure gradient. The level of laminin in the hepatic vein (mean value: 1.83 U/ml) was significantly (p less than 0.05) higher than that in the cubital vein (mean value 1.68 U/ml). In both vascular regions the glycoprotein levels increased with the degree of fibrosis, reaching their highest concentrations in cirrhosis (2.16 +/- 0.84 U/ml, p less than 0.001) (normal range: 0.81-1.43 U/ml). In all chronic liver diseases there was a significant positive correlation between the level of serum laminin and portal vein pressure (rs 0.70, p less than 0.001), which prompted us to calculate some criteria of the diagnostic validity of raised laminin for portal hypertension (portal venous pressure greater than or equal to 5 mm Hg). At a cut-off concentration of laminin of 1.45 U/ml, sensitivity is 0.87, specificity 0.74, diagnostic efficiency 0.81, and the likelihood ratio 3.4. Positive and negative predictive values at the same cut-off and at a prevalence of portal hypertension in this study of 50% are 0.77 and 0.85, respectively. Serum laminin may prove to be a potentially useful biochemical marker of portal hypertension.