Choriogonadotropin and its beta subunit separated by hydrophobic-interaction chromatography and quantified in serum during pregnancy by time-resolved immunofluorometric assays.

Abstract Concentrations of human choriogonadotropin (hCG) and its free beta subunit (beta hCG) were measured in serum by highly sensitive and specific time-resolved immunofluorometric assays (IFMAS). The results were confirmed by completely separating beta hCG and hCG by a novel method based on hydrophobic-interaction chromatography. We used three monoclonal antibodies in two different combinations. In both assays an antibody reacting with both free beta hCG and with intact hCG was immobilized onto the wall of a microtiter strip well. For assay of intact hCG we used as the indicator antibody an antibody against the alpha subunit, labeled with a europium chelate. For assay of beta hCG we used an indicator antibody that reacted only with the free beta subunit. hCG cross-reacted in the assay of beta hCG by 0.6%. Quantifying hCG in serum after in vitro fertilization showed that, seven to eight days after embryo transfer, the hCG concentration started to increase, thereafter increasing with a doubling time of 1.9 days during the following three weeks. hCG concentrations in serum peaked six to 10 weeks later, corresponding to eight to 12 weeks after the last menstrual period. Throughout pregnancy, measurable amounts of beta hCG were present in serum. The highest beta hCG/hCG ratio (maximum 7.3%, median 3.0%) was observed during early gestation. During the fourth to 13th weeks after the last menstrual period the ratio of beta hCG/hCG decreased gradually, being 1.0% during the second and third trimesters.

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Svangerskapsdatering

Norsk Epidemiologi ◽

10.5324/nje.v27i1-2.2397 ◽

2017 ◽

Vol 27 (1-2) ◽

Author(s):

Håkon K. Gjessing

Keyword(s):

Embryo Transfer ◽

Population Based ◽

Menstrual Period ◽

English Abstract ◽

Last Menstrual Period ◽

Vitro Fertilization ◽

Short Overview ◽

Wide Range ◽

Pregnancy Dating

SAMMENDRAG Svangerskapsdatering er et komplekst felt med mange aspekter. Minst tre svært forskjellige metoder for datering er i bruk: siste menstruasjon, ultralyd samt tidspunkt for fertilisering eller overføring av embryo ved in vitro-fertilisering. Bare innenfor ultralyddatering finnes en stor mengde forskjellige “formler” for datering. Jeg gir her en kort oversikt over de forskjellige tilnærmingene til svangerskapsdatering og viser noen av prinsippene bak populasjonsbasert ultralyddatering.ENGLISH ABSTRACT Pregnancy dating is a complex and multifaceted field. At least three very different methods for dating are commonly used: last menstrual period, ultrasound, and date of fertilization or embryo transfer during in vitro fertilization. Within ultrasound dating alone there is a wide range of different “formulas” for dating. I present a short overview over the different approaches to pregnancy dating and show some of the principles behind population-based ultrasound dating.

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Cutoff points of serum beta-hCG levels to predict pregnancy after different in vitro fertilization treatments

10.26226/morressier.5912d9ead462b8029238621d ◽

2017 ◽

Author(s):

Marisa Fernandez Perez

Keyword(s):

In Vitro Fertilization ◽

Vitro Fertilization ◽

Beta Hcg ◽

Cutoff Points

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An evaluation of four serum tests for pregnancy.

Clinical Chemistry ◽

10.1093/clinchem/29.3.561 ◽

1983 ◽

Vol 29 (3) ◽

pp. 561-563 ◽

Cited By ~ 1

Author(s):

K W Ryder ◽

R A Munsick ◽

T O Oei ◽

P C Young ◽

H F Blackford

Keyword(s):

Positive Result ◽

Early Pregnancy ◽

Beta Subunit ◽

The Other ◽

Analytical Sensitivity ◽

Negative Results ◽

Human Choriogonadotropin ◽

Beta Hcg

Abstract We evaluated four pregnancy tests (Biocept-G, Beta-CG, Preg/Stat, and HCG-Beta Screen), using sera from 59 nonpregnant subjects and 77 patients with serum human choriogonadotropin beta-subunit (beta-hCG) concentrations ranging from 4 to 100 000 int. units/L. The results obtained for each test were compared with the results predicted on the basis of the sample's beta-hCG concentration and the beta-hCG concentration the manufacturer claimed necessary for a positive result (the test's analytical sensitivity). Biocept-G had the best sensitivity (100%), specificity (98.9%), and accuracy (99.2%). Beta-CG had the poorest sensitivity (86.4%), Preg/Stat the poorest specificity (87.5%), and accuracy (92.6%). We confirmed the manufacturer's claimed analytical sensitivity (200 int. units/L) for the Biocept-G procedure, but our calculated analytical sensitivity for the other tests was significantly different from that claimed by their manufacturers. Best results were obtained with Biocept-G, but with its analytical sensitivity of 200 int. units/L, samples from early pregnancy will give negative results. None of the pregnancy tests evaluated here will establish the presence or absence of early pregnancy with certainty.

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Evaluation of a solid-phase enzyme immunoassay for human choriogonadotropin beta subunit.

Clinical Chemistry ◽

10.1093/clinchem/29.11.1964 ◽

1983 ◽

Vol 29 (11) ◽

pp. 1964-1966 ◽

Cited By ~ 2

Author(s):

D D Davey ◽

M M Sample ◽

T O Oei

Keyword(s):

Enzyme Immunoassay ◽

Solid Phase ◽

Cross Reactivity ◽

Beta Subunit ◽

Neoplastic Disease ◽

Standard Curve ◽

Human Choriogonadotropin ◽

Beta Hcg ◽

Substantial Problem ◽

Sample Dilution

Abstract We evaluated a quantitative solid-phase enzyme immunoassay for human choriogonadotropin beta subunit (beta-HCG) with anti-beta-HCG:horseradish peroxidase conjugate, recently marketed by Abbott Laboratories. We compared results on 56 patients' serum specimens, obtained mostly for followup of neoplastic disease, with those by a competitive radioimmunoassay kit. The correlation was good, the differences being of little clinical significance. Linear regression in the low and intermediate ranges gave a slope of 0.93, a y-intercept of 0.34, and a correlation coefficient of 0.97. Precision studies yielded an interassay CV of 6.4% in the intermediate range and 13% in the low range. Sensitivity was 0.69 int. unit/L. Cross reactivity was 1 to 2% with specimens fortified with lutropin or follitropin. The only substantial problem was with linearity in the upper part of the standard curve, especially in the interval, 100-200 int. units/L. This problem is obviated by adequate sample dilution.

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The role of early post-implantation beta-HCG levels in the outcome of pregnancies following in-vitro fertilization

Human Reproduction ◽

10.1093/oxfordjournals.humrep.a136763 ◽

1988 ◽

Vol 3 (5) ◽

pp. 663-667 ◽

Cited By ~ 24

Author(s):

Jehoshua Dor ◽

Edwina Rudak ◽

Siegfried Rotmench ◽

David Levran ◽

Josef Blankstein ◽

...

Keyword(s):

In Vitro Fertilization ◽

Vitro Fertilization ◽

Beta Hcg ◽

Post Implantation

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Evidence that the alpha-subunit influences the specificity of receptor binding of the equine gonadotrophins

Journal of Endocrinology ◽

10.1677/joe.0.1550241 ◽

1997 ◽

Vol 155 (2) ◽

pp. 241-245 ◽

Cited By ~ 6

Author(s):

M Chopineau ◽

N Martinat ◽

H Marichatou ◽

C Troispoux ◽

C Auge-Gouillou ◽

...

Keyword(s):

Receptor Binding ◽

Molecular Basis ◽

Binding Specificity ◽

Chorionic Gonadotrophin ◽

Beta Subunit ◽

Alpha Subunit ◽

Beta Hcg ◽

In Vitro Bioassays ◽

Receptor Binding Specificity

Horse LH/chorionic gonadotrophin (eLH/CG) exhibits, in addition to its normal LH activity, a high FSH activity in all other species tested. Donkey LH/CG (dkLH/CG) also exhibits FSH activity in other species, but about ten times less than the horse hormone. In order to understand the molecular basis of these dual gonadotrophic activities of eLH/CG and dkLH/CG better, we expressed, in COS-7 cells, hybrids between horse and donkey subunits, between horse or donkey alpha-subunit and human CG beta (hCG beta), and also between the porcine alpha-subunit and horse or donkey LH/CG beta. The resultant recombinant hybrid hormones were measured using specific FSH and LH in vitro bioassays which give an accurate measure of receptor binding specificity and activation. Results showed that it is the beta-subunit that determines the level of FSH activity, in agreement with the belief that it is the beta-subunit which determines the specificity of action of the gonadotrophins. However, donkey LH/CG beta combined with a porcine alpha-subunit exhibited no FSH activity although it showed full LH activity. Moreover, the hybrid between horse or donkey alpha-subunit and hCG beta also exhibited only LH activity. Thus, the low FSH activity of dkLH/CG requires an equine (donkey or horse) alpha-subunit combined with dkLH/CG beta. These results provide the first evidence that an alpha-subunit can influence the specificity of action of a gonadotrophic hormone.

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