To clarify the clinical significance of
vitronectin, we compared the concentration of plasma
vitronectin with serum fibrous markers and liver function test values in patients with chronic
liver diseases. We also evaluated the
vitronectin content in the liver by means of
enzyme-linked
immunosorbent assay and the localization of
vitronectin in liver tissue with
enzyme immunohistochemistry. In chronic
liver disease, the concentration of plasma
vitronectin was significantly lower than that in healthy controls, being related to the severity of
liver disease. The plasma levels of
vitronectin showed no correlation to fibrous markers but a significant correlation with those of
serum albumin and prothrombin time. On the other hand, the content of
vitronectin in liver tissue was significantly increased in chronic
liver disease compared with that in normal controls. In the normal liver,
vitronectin was observed in the portal area by light microscopy. In
chronic hepatitis and
cirrhosis,
vitronectin was found in the connective tissue around the portal and central veins and in the areas of piecemeal and focal
necrosis. These findings suggested that
vitronectin is deposited in injured tissue through the process of repair and
fibrosis and plays an important role as an adhesive
protein. Moreover, the lower levels of plasma
vitronectin in chronic
liver disease may be due to its decreased synthesis, deposition or both in injured tissue.