Isoelectric heterogenity of human chorionic gonadotropin: Presence of choriocarcinoma specific components.

Comparative clinical studies were carried out on the isoelectric heterogeneity of serum human chorionic gonadotropin (hCG) in normal pregnancy and trophoblastic disease by means of isoelectric focusing and radioimmunoassay. The immunoreactive hCG components in sera of women with normal pregnancy were composed of seven peaks with isoelectric points of 3.9, 4.1, 4.4, 4.7, 5.0, 5.8, and around 6.7. These same components were also observed in the sera of patients with hydatidform mole and invasive mole. However, in the sera of patients with choriocarcinoma, three additional components with isoelectric points of 3.2, 3.5, and 3.7 were observed in considerable amounts. The presence of those three specific components suggests the possibility to develop a new diagnostic procedure for the detection of choriocarcinoma.