[The follow-up of trophoblastic disease by using an hCG-CTP enzyme immunoassay]

In the management of a chorionic disease, human chorionic gonadotropin (hCG) is the most reliable tumor marker. However, hCG has a low titer, so that it cannot be strictly distinguished from the human luteinizing hormone (hLH) by the traditional method that uses a hemagglutinin reaction (HAR) or by a radioimmunoassay (RIA). Recently, however, the detection of the beta-COOH-terminal peptide of hCG (hCG-CTP) by an enzyme immunoassay has made it possible to clearly distinguish hCG from hLH, and from April, 1987 to December, 1989, 13 trophoblastic diseases have been managed using this new technique. Results have shown that human chorionic gonadotropin-CTP, when compared to other methods of measurement, is the most sensitive tumor marker and as it is the most accurate, it should be used in careful follow-up observations of a chorionic disease.