Separation and identification of serum gamma-glutamyl transpeptidase isoenzymes by wheat germ agglutinin affinity electrophoresis: a basic analysis and its clinical application to various liver diseases.

Serum gamma-glutamyl transpeptidase (gamma-GTP) was separated into four fractions by using wheat germ agglutinin (WGA) affinity electrophoresis. By two-dimensional analysis using gel filtration combining with affinity electrophoresis with WGA, anti-alpha 1-lipoprotein antiserum or anti-beta-lipoprotein antiserum, properties of each fraction were identified as a high molecular WGA affinity fraction (HM), a relatively high molecular beta-lipoprotein binding fraction (beta-LP), an intermediate molecular alpha-lipoprotein binding fraction (alpha-LP) and a low molecular fraction (LM). Quantitative alterations in each fraction of gamma-GTP in the serum of patients with various liver diseases and gall stones (GS) were also examined. In patients with hepatocellular carcinoma (HCC), the HM fraction was more increased compared with those in patients with non-alcoholic liver cirrhosis (LC) and chronic hepatitis (CH). The rate of HM fraction was correlated with total activity of serum gamma-GTP in HCC patients. In alcoholic liver disease (ALD), no remarkable differences of the rate of each gamma-GTP fraction were shown among alcoholic LC, alcoholic hepatitis, alcoholic CH and fatty liver patients. It was, however, shown that the rate of the LM fraction decreases and the HM fraction increases gradually in accordance with an increase in serum gamma-GTP activity in ALD. These data indicate that serum gamma-GTP isoenzymes can be separated clearly into four fractions by using WGA affinity electrophoresis, the HM fraction of serum gamma-GTP is relatively increased in HCC patients, and detection of the HM fraction may be useful to diagnose HCC, although it can be increased in ALD patients with high serum gamma-GTP activity.