Serum markers for hepatic fibrosis in alcoholic liver disease: which is the best marker, type III procollagen, type IV collagen, laminin, tissue inhibitor of metalloproteinase, or prolyl hydroxylase?
Although various serum markers for the evaluation of hepatic fibrosis have been introduced, it remains unclear which is the best marker to evaluate the hepatic fibrosis observed in alcoholic liver disease (ALD). In this study, we measured serum concentrations of the immunoreactive beta-subunit of prolyl hydroxylase, procollagen type III peptide, the 7S domain (7S-IV) and triple-helix domain (TH-IV) of type IV collagen, laminin, and tissue inhibitor of metalloproteinase (TIMP) in patients with and without ALD (non-ALD), and controls to evaluate the best serum marker reflecting the characteristic histologic features of ALD. After Azan-Mallory and silver-impregnated reticulin staining, histologic specimens were examined; and the degree of hepatic fibrosis was classified as mild, moderate, or severe. Although serum concentrations of all markers, except for TIMP, in patients with each type and stage of liver disease were higher than cut-off values and these concentrations increases with the progression of liver disease, statistical analyses indicate that serum TH-IV concentration is the best marker to distinguish ALD from non-ALD. A good correlation was also found between the hepatic type IV collagen content and serum TH-IV, but not serum 7S-IV concentration. Moreover, after abstinence from alcohol, serum concentrations of TH-IV decreased more quickly than other serum markers. These results clearly suggest that, compared with other markers, serum concentration of TH-IV may more strongly reflect the histologic features of ALD. However, other serum markers, except for TIMP, may be useful in evaluating the degree of hepatic fibrosis.