Evaluation of serum laminin P1, procollagen-III peptides, and N-acetyl-beta-glucosaminidase for monitoring the activity of liver fibrosis.

Chronic liver diseases are characterized by an increase in connective tissue components in liver tissue. The determination of Col 1-3 peptide of type III procollagen (P-III-P) in serum of patients seems to be a useful parameter of hepatic fibroplasia. Specific radioimmunoassays are available for Col 1-3 (P-III-P) and the Col 1 and Col 1-3 (P-III-P-Fab) peptides of type III procollagen and for laminin P1 fragment. These proteins and the activity of N-acetyl-beta-glucosaminidase (beta-NAG) were measured in 94 patients with chronic liver diseases, and in 74 healthy controls. In addition, direct immunofluorescence studies were done for laminin P1 in normal and fibrotic liver tissues. In normal human liver, laminin was found in the basement membrane of bile ducts and in blood vessel walls. In fibrotic liver tissue, laminin additionally occurred in periportal areas and in sinusoids co-distributed with other connective tissue components. In serum concentrations of P-III-P, P-III-P-Fab and laminin were higher in patients than in healthy subjects. Laminin concentration was increased in early stages of chronic liver disease, possibly as a marker of regeneration; the highest concentrations were in active cirrhosis and chronic active hepatitis. The determination of P-III-P and P-III-P-Fab provided information on synthesis and degradation of type III collagen: In inactive cirrhosis, Col 1 peptide was increased in relation to Col 1-3 peptide.(ABSTRACT TRUNCATED AT 250 WORDS)