SERUM DES-GAMMA-CARBOXYPROTHROMBIN LEVEL BY A MODIFIED ENZYME-IMMUNOASSAY METHOD IN HEPATOCELLULAR-CARCINOMA - CLINICAL-SIGNIFICANCE IN SMALL HEPATOCELLULAR-CARCINOMA

BACKGROUND/AIMS: In the diagnosis of hepatocellular carcinoma (HCC), s erum des-gamma-carboxyprothrombin (DCP) is a useful tumor marker. The conventional immunoassays for measurement of DCP levels, however, are not sensitive enough to detect small HCC. Therefore, we intended to el evate the minimal detection level of DCP by a modified enzyme linked i mmunosorbent assay method. METHODOLOGY: This modified assay method is similar to the conventional enzyme linked immunosorbent assay (ELISA) method, but the first reaction occurs overnight. As a result, the mini mal detection levels of DCP varied from 0.06 AU/ml, by the conventiona l method, to 0.008 AU/ml, by the modified method. Two hundred and twen ty five serum samples from 100 patients with HCC, 75 with liver cirrho sis and 50 with chronic hepatitis were subjected to the present study. Simultaneous determinations of serum DCP by the modified assay and a- fetoprotein (AFP) levels were performed. RESULTS: Eighty five of 100 p atients with HCC had increased DCP levels of more than 0.008 AU/ml. Th is method yielded a sensitivity of 85%, a specificity of 90% and a tot al accuracy value of 88%. In 27 patients with small HCC (less than 30 mm in diameter), 12 had elevated DCP levels, resulting in a sensitivit y of 44%. When the modified DCP assay together with AFP measurement (m ore than 20 ng/ml) were introduced, the sensitivity was 67% in the 27 patients with small HCC. CONCLUSIONS: This modified ELISA method incre ased the sensitivity in patients with small HCC, and the combination a ssay of serum DCP and AFP levels was more useful for the early diagnos is of HCC.