[Newly developed enzyme immunoassay for hCG-beta CTP and its significance in follow-up practice of trophoblastic disease].

An enzyme immunoassay (EIA) for hCG-beta CTP was newly developed. Anti hCG-beta CTP antibody was prepared from antiserum to the synthetic peptide corresponding to the carboxyl terminal region by immunization of rabbits with hCG-beta subunit. Specimens to be tested were reacted with the antibody labelled with peroxidase and determined with a spectrophotometer after the addition of o-phenylenediamine. It was found that the sensitivity of the assay for hCG in sera was 0.2miu/ml and that values for the assay were significantly correlated with those for the RIA assay for hCG-beta (r = 0.916, Y = 1.27X + 1.8). Cross reactivity with LH, FSH, hCG-beta or hCG-alpha was observed to be 0.18%, 0.05%, 10.4% or less than 0.011% respectively. The assay has been applied in the management of hydatidiform mole, invasive mole and choriocarcinoma, indicating its usefulness because of the increase in sensitivity roughly 25 times or 10 times as great as hemagglutination or hCG-beta RIA assay.