[Measurement of serum immunoreactive beta-glucuronidase: a possible serological marker for histological hepatic cell necrosis and to predict the histological progression of hepatitis].

beta-Glucuronidase, a lysosomal hydrolase, was purified from human liver tissue, and an enzyme-linked immunosorbent assay was developed using specific antibody against the enzyme. Using the assay procedure, the serum immunoreactive beta-glucuronidase (beta-glucuronidase) was determined in 190 patients with various liver diseases and in 53 healthy controls to examine whether or not the serum level of beta-glucuronidase would successfully reflect the degree of histological hepatic cell necrosis. beta-Glucuronidase was also determined at regular intervals in 28 patients with chronic hepatitis to investigate the clinical usefulness of serial measurement of the enzyme to predict the histological progression of hepatitis. These 28 patients could be subdivided into three groups, "continuously low type", "labile type" and "elevated type" according to the profiles of fluctuation of serum beta-glucuronidase values. Serum beta-glucuronidase was significantly increased in patients with hepatoma, liver cirrhosis and chronic active hepatitis compared with normal controls. There was significant positive correlation between the beta-glucuronidase and the degree of hepatic cell necrosis determined by histological observation, on the other hand, there was no statistical correlation between the transaminase activities and the degree of hepatic cell necrosis. It was confirmed in immunohistochemical study that the increased beta-glucuronidase in serum has been released from necrotic hepatic cells into blood stream. It was speculated that the elevation of serum transaminase activities had resulted from the alteration in the membrane permeability of hepatic cells rather than from hepatocellular necrosis. Histological progression of hepatitis was found in 8 of 10 patients (80%) of "labile" and "elevated type", while it was found only 3 of 18 patients (16.7%) of "continuously low type". These results suggested that the serial measurement of beta-glucuronidase could be used for an indicator to predict the histological progression of hepatitis.