[M2-type pyruvate kinase in the diagnosis of hepatocarcinoma--a pilot study]

By using Fab'-enzyme labelled immunosorbent assay (ELISA) at a sensitivity of picogram (10(-12) g or pg) level, M-type pyruvate kinase (M-PyK) in the plasma was determined in 47 healthy adults and 26 hepatocellular carcinoma (HCC) patients. The upper limits of M-PyK in the normal male and female were 1.1 and 1.4 ng/ml. The plasma M-PyK in HCC patients was significantly increased about 5 fold of the average normal level with a positive rate of about 95%. In 6 cases of subclinical small hepatocarcinoma and 7 cases of HCC with normal serum alpha-fetoprotein level, the plasma M-PyK was increased, whereas the plasma M-PyK levels were normal in acute or chronic hepatitis and the other benign diseases. After tumor resection, the plasma M-PyK returned to the normal value, but increased again in cases with recurrence, suggesting that the increased M-PyK in the plasma of HCC patients originates from M2-type PyK in HCC tissue. The plasma M2-PyK also increased in patients with carcinoma of the digestive tract, so M2-PyK may become a new marker of malignant tumors.