[Connective tissue polypeptides in serum: new parameters of connective tissue synthesis and degradation in liver...

With the invention of drugs that effectively and specifically inhibit excessive collagen synthesis in the liver, a growing interest in serum assays that assess fibrogenesis, i.e. the de novo formation and fibrolysis, i.e. the removal of connective tissue in the liver, may be anticipated. Several serum assays for connective tissue polypeptides fulfil the criteria of sensitivity and specificity for chronic liver diseases. The aminoterminal procollagen type III peptide (PIIINP) correlates with hepatic fibrogenesis, whereas the propeptides of basement membrane collagen (PIVNP and PIVCP) and the basement membrane glycoprotein laminin reflect the enhanced turnover of basement membranes of the sinusoids as well as of proliferating bile ducts and blood vessels in active fibrosis. Circulating collagen type VI results from degradation of interstitial microfilaments and undulin appears to be released upon remodeling of the hepatic architecture. Combined measurement of selected parameters may allow a non-invasive assessment of the balance between fibrogenesis and fibrolysis on a day-to-day basis, especially in the light of potential antifibrotic therapy.