SERUM TYPE-IV COLLAGEN IN VARIOUS LIVER-DISEASES IN COMPARISON WITH SERUM 7S COLLAGEN, LAMININ, AND TYPE-III PROCOLLAGEN PEPTIDE

The clinical significance of the immunoreactive triple helical domain of type IV collagen in serum was evaluated in 73 healthy controls and 161 patients with various biopsy-proven liver diseases. Although serum levels of type III procollagen peptide were increased in all liver di seases, those of type IV collagen, 7S collagen, and laminin were princ ipally increased in chronic liver diseases associated with hepatic fib rogenesis/fibrosis. In both non-alcoholic and alcoholic liver diseases , 7S collagen was increased in serum, while type IV collagen and lamin in in serum were particularly increased in alcoholic liver diseases an d in hepatocellular carcinoma, in which latter the sensitivity was gre ater for type IV collagen than for laminin. Gel filtration analysis in Sephacryl S-400 revealed type IV collagen in serum to be a single mol ecular form with a molecular weight that correspond to type IV collage n, whereas 7S collagen was recognized as several heterogeneous macromo lecules. These findings indicate that serum type IV collagen is derive d from the type IV protocollagen pool, and is a sensitive marker for t he fibrogenetic process in hepatic basement membranes.