Hepatic fibrosis and its serum markers: a review

Hepatic fibrosis is characterized by a progressive increase in extracellular matrix in the liver, formed by collagens, proteoglycans and glycoproteins, qualitatively similar but quantitatively different from that in normal liver. A great number of matrix-related substances have been investigated in serum in order to identify reliable serum markers of liver fibroplasia. Among the various cleavage products of collagen precursor, the NPIIIP collagen is at present considered the most reliable serum marker of active fibrogenesis in liver, useful in monitoring the progression of fibrosis and in assessing the therapeutic efficacy of antifibrotic drugs. Lam-P1 and type IV collagen are now regarded as putative markers of basement membrane formation and sinusoids capillarization, an important pathological process in fibrosing disease, related to the impairment of hepatic circulation. Other serum-measured matrix-related substances, e.g. enzymes involved in collagen metabolism, fibronectin and proteoglycans, have not proved to reflect liver fibroplasia reliably. In spite of the availability of useful serum markers, the assessment of hepatic fibrosis is still based on liver biopsy.