Immunofluorometric demonstration and quantification of placental protein 5 in the absence of pregnancy.
This time-resolved immunofluorometric assay (IFMA) developed for measurement of placental protein 5 (PP5) involves two antibodies: a monoclonal anti-PP5 antibody attached to a solid phase and an europium(III) chelate-labeled polyclonal anti-PP5 antibody as a tracer. The measuring range is 0.05-100 micrograms/L and the detection limit is 20 times lower than that of a PP5 radioimmunoassay (RIA) performed with the same polyclonal antiserum. By IFMA, PP5 could be detected and quantified in all plasma and serum samples of nonpregnant and pregnant individuals, whereas PP5 was undetectable by RIA in serum of healthy men and nonpregnant women. The mean concentration of PP5 in sera from men was 0.43 micrograms/L (SD 0.13, range 0.19-0.75, n = 47) and in sera from nonpregnant women 0.49 micrograms/L (SD 0.19, range 0.20-0.90, n = 41). PP5 concentrations in serum showed no systematic variation during the menstrual cycle. In serum samples from 60 pregnant women the results obtained by IFMA and RIA correlated well (r = 0.97).
Bützow
R
R
First Department of Obstetrics and Gynecology, Helsinki University Central Hospital, Finland.
Alfthan
H
H
Stenman
U H
UH
Suikkari
A M
AM
Bohn
H
H
Seppälä
M
M
D005260:Female; D006023:Glycoproteins; D006801:Humans; D008597:Menstrual Cycle; D011257:Pregnancy Proteins / Q000097:blood*; D011863:Radioimmunoassay / Q000379:methods
D006023:Glycoproteins; D011257:Pregnancy Proteins; C021240:tissue-factor-pathway inhibitor 2