Digitalis-like immunoreactive substances in maternal and umbilical cord plasma: a comparative sensitivity study of fluorescence polarization immunoassay and microparticle enzyme immunoassay.
Digitalis-like immunoreactive substances (DLIS) obtained from maternal and umbilical cord plasma at delivery were measured by fluorescence polarization immunoassay (FPIA; TDX, Abbott) and microparticle enzyme immunoassay (MEIA; IMX, Abbott). In each sample, concentrations of dehydroepiandrosterone, dehydroepiandrosterone sulfate, estradiol, estriol, hydrocortisone, progesterone, and testosterone were measured by radioimmunoassay, and cross-reaction tests of DLIS with these substances were conducted. By FPIA, the concentration of DLIS in umbilical cord plasma (0.55 +/- 0.22 ng/mL) was significantly higher than that in maternal plasma (0.23 +/- 0.11 ng/mL). In the cross-reaction tests, when the concentration of dehydroepiandrosterone sulfate was higher than 1.0 microg/mL or that of progesterone was higher than 0.5 microg/mL, DLIS were detected by FPIA. However, DLIS were not found either in the samples or in the cross-reaction tests by MEIA. By radioimmunoassay, there was no significant difference in the dehydroepiandrosterone sulfate concentration between the maternal plasma (2,917 +/- 1,001 ng/mL) and the umbilical cord plasma (1,957 +/- 376 ng/mL). The progesterone concentration in the umbilical cord plasma (310.0 +/- 85.7 ng/mL) was significantly higher than that in the maternal plasma (126.4 +/- 38.5 ng/mL). These results suggest that dehydroepiandrosterone sulfate in maternal plasma and progesterone in maternal and umbilical cord plasma may be measured as digoxin by FPIA.
Ijiri
Yoshio
Y
Department of Pharmacy, Osaka Medical College Hospital, Takatsuki, Osaka, Japan. phc003@poh.osaka-med.ac.jp
Hayashi
Tetsuya
T
Kamegai
Hideki
H
Ohi
Kazuhide
K
Suzuki
Kaoru
K
Kitaura
Yasushi
Y
Takenaka
Hiroshi
H
D000328:Adult; D002298:Cardenolides; D003429:Cross Reactions; D004077:Digoxin / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D016231:Fluorescence Polarization Immunoassay / Q000379:methods; D012739:Gonadal Steroid Hormones / Q000097:blood; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D008875:Middle Aged; D009035:Mothers; D011247:Pregnancy; D011863:Radioimmunoassay; D012503:Saponins / Q000097:blood*; D012680:Sensitivity and Specificity
D002298:Cardenolides; D012739:Gonadal Steroid Hormones; D012503:Saponins; C034504:digoxin-like factors; D004077:Digoxin