Change in human chorionic gonadotropin in gestational trophoblastic disease observed during the course of chemotherapy.

This study investigates the physicochemical characteristics of human chorionic gonadotropin (hCG) in gestational trophoblastic disease (GTD), with special reference to the clinical course of chemotherapy and prognosis. In gel high performance liquid chromatography (HPLC), the hCG molecules from normal pregnancy and from the hydatidiform mole had the same molecular form as standard purified hCG, whereas hCG from choriocarcinoma was inconsistent in molecular form, containing molecules which are smaller, the same or larger than those of standard purified hCG. In two fatal choriocarcinoma patients, large hCG and large hCG alpha were found in the urine samples collected within one month prior to death. In a chromatofocusing study, the chromatofocusing pattern of hCG from GTD was acidic and similar to that of early pregnancy. The chromatofocusing patterns did not alter or were altered only slightly during the course of chemotherapy. In a Concanavalin A-Sepharose (Con A) chromatography study, the Con A binding shifted from low to high binding in patients with GTD who were responsive to chemotherapy. In summary, the molecular form, electric charge and Con A binding of hydatidiform mole hCG are similar to those of early pregnancy hCG and standard purified hCG, whereas the molecular form and Con A binding of choriocarcinoma are different from those of early pregnancy hCG and standard purified hCG. The presence of smaller or larger molecular forms of hCG may be an ominous sign, whereas the presence of high Con A binding may be a favorable sign. The chromatofocusing pattern seems to be unrelated to the clinical course of chemotherapy.