Total amounts of circulating human chorionic gonadotrophin α and β subunits can be assessed throughout human pregnancy using immunoradiometric assays calibrated with the unaltered and thermally dissociated heterodimer

Nagy, Adrienn; Glinoer, Daniel; Picelli, Gino; Delogne-Desnoeck, J.; Fleury, B.; Courte, Claude; Kaufman, JM; Robyn, Claude; Meuris, Sylvain

doi:10.1677/joe.0.1400513

Cited by 18 publications

(14 citation statements)

References 21 publications

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“…Peak hCG levels vary widely among individuals, and they usually range between 30,000 and 100,000 IU/liter. The peak lasts for only a few days, and thereafter, serum hCG decreases gradually to concentrations in the range of 5,000 to 20,000 IU/liter around midgestation (321). Peak hCG levels are significantly greater and prolonged in the case of twin pregnancy (322).…”

Section: Significance Of Low Serum Tshmentioning

confidence: 99%

Thyroid Function and Human Reproductive Health

Krassas¹,

2010

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Via its interaction in several pathways, normal thyroid function is important to maintain normal reproduction. In both genders, changes in SHBG and sex steroids are a consistent feature associated with hyper- and hypothyroidism and were already reported many years ago. Male reproduction is adversely affected by both thyrotoxicosis and hypothyroidism. Erectile abnormalities have been reported. Thyrotoxicosis induces abnormalities in sperm motility, whereas hypothyroidism is associated with abnormalities in sperm morphology; the latter normalize when euthyroidism is reached. In females, thyrotoxicosis and hypothyroidism can cause menstrual disturbances. Thyrotoxicosis is associated mainly with hypomenorrhea and polymenorrhea, whereas hypothyroidism is associated mainly with oligomenorrhea. Thyroid dysfunction has also been linked to reduced fertility. Controlled ovarian hyperstimulation leads to important increases in estradiol, which in turn may have an adverse effect on thyroid hormones and TSH. When autoimmune thyroid disease is present, the impact of controlled ovarian hyperstimulation may become more severe, depending on preexisting thyroid abnormalities. Autoimmune thyroid disease is present in 5-20% of unselected pregnant women. Isolated hypothyroxinemia has been described in approximately 2% of pregnancies, without serum TSH elevation and in the absence of thyroid autoantibodies. Overt hypothyroidism has been associated with increased rates of spontaneous abortion, premature delivery and/or low birth weight, fetal distress in labor, and perhaps gestation-induced hypertension and placental abruption. The links between such obstetrical complications and subclinical hypothyroidism are less evident. Thyrotoxicosis during pregnancy is due to Graves' disease and gestational transient thyrotoxicosis. All antithyroid drugs cross the placenta and may potentially affect fetal thyroid function.

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Section: Significance Of Low Serum Tshmentioning

confidence: 99%

Thyroid Function and Human Reproductive Health

Krassas¹,

2010

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“…Although the gonococcal IgA1 proteases did not cleave the a subunit of hCG, we determined whether the association of the a subunit of hCG with the b subunit, as in intact hCG, influenced sensitivity of the hormone to cleavage by the IgA1 proteases. We used unlabeled hCG because the 125 I label incorporates predominantly into the a subunit and, therefore, little of the b subunit is labeled [10]. Thus, after incubation of unlabeled hCG with the IgA1 proteases, the samples were reduced and electrophoresed, and hCG fragments were detected by immunoblotting with antibody to b-hCG (aa 109-145).…”

Section: Resultsmentioning

confidence: 99%

Cleavage of the Hormone Human Chorionic Gonadotropin, by the Type 1 IgA1 Protease ofNeisseria gonorrhoeae,and Its Implications

et al. 2001

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The hormone human chorionic gonadotropin (hCG) serves to maintain the fetus during early pregnancy and regulate the onset of labor in late pregnancy. hCG also prevents Neisseria gonorrhoeae from developing invasive characteristics. Part of the beta subunit of hCG has an amino acid sequence similar to that of the hinge of human IgA1, which is the site of action of IgA1 proteases. This study examined the sensitivity of hCG to gonococcal IgA1 proteases, by means of autoradiography, immunoblotting, and RIA. hCG was cleaved in the beta subunit by the type 1 but not the type 2 IgA1 proteases of N. gonorrhoeae. hCG cleavage by gonococcal IgA1 proteases in vivo may increase the invasiveness of the pathogen and destroy its natural biologic activity, with major consequences for the fetus and the pregnancy.

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“…Indeed, these data suggest that, throughout pregnancy, hCG dimer formation is constantly dependent upon ßhCG synthesis. This hypoth¬ esis was recently supported by a study showing that the circulating levels of total ahCG and total ßhCG subunits were equimolar in early pregnancy and the ratio of ahCG to ßhCG then increased until term (Nagy et al 1994). …”

Section: Introductionmentioning

confidence: 84%

“…Total amounts of each subunit were determined in each sample as the sum of hCG level and subunit level expressed in the same IU system as described previously (Nagy et al 1994). Briefly, conversion factors between the IU systems used for the and ß subunits and that used for the heterodimer were assessed using given amounts of intact and thermally dissociated purified hCG preparation.…”

Section: Methodsmentioning

confidence: 99%

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Placental production of human chorionic gonadotrophin α and β subunits in early pregnancy as evidenced in fluid from the exocoelomic cavity

Nagy¹,

Jauniaux²,

Meuris³

1994

Journal of Endocrinology

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Levels of human chorionic gonadotrophin (hCG) and of its free alpha and beta subunits were measured using specific immunoradiometric assays in exocoelomic fluid (ECF) and maternal serum (MS) collected from five pregnant women at 6.6-8 weeks of gestation. Mean levels of hCG and its free subunits were significantly (P < 0.001) higher in ECF than in MS: 3.5-fold for hCG, 600-fold for free alpha hCG and 38-fold for beta hCG. There was no correlation between either hCG levels or levels of its free subunits in ECF and MS. On a molar basis, the quantity of free alpha hCG subunit expressed as a percentage of the total (free+combined) amount was 83% in ECF and 2.7% in MS (P < 0.001). The amount of free beta hCG subunit as a percentage of the total was 22% in ECF and 3.5% in MS (P < 0.001). The ratio of the total amounts of alpha- and beta hCG subunits amounted to 4.6 in ECF and 0.99 in MS (P < 0.001). The heterogeneity of hCG was further investigated by polyacrylamide gel electrophoresis followed by immunoblotting. Several bands with molecular mass ranging from 42 to 57 kDa, corresponding to hCG dimers, were immunodetected in ECF and MS with anti-alpha hCG and anti-beta hCG monoclonal antibodies. A free 35 kDa beta hCG immunoreactive band was found in ECF and MS. A free alpha hCG immunoreactive band was observed at 23 kDa in ECF and at 21 kDa in MS. These findings suggest that the exocoelomic cavity is a reservoir where hCG and its subunits produced by trophoblast accumulate directly.(ABSTRACT TRUNCATED AT 250 WORDS)

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Total amounts of circulating human chorionic gonadotrophin α and β subunits can be assessed throughout human pregnancy using immunoradiometric assays calibrated with the unaltered and thermally dissociated heterodimer

Cited by 18 publications

References 21 publications

Thyroid Function and Human Reproductive Health

Thyroid Function and Human Reproductive Health

Cleavage of the Hormone Human Chorionic Gonadotropin, by the Type 1 IgA1 Protease ofNeisseria gonorrhoeae,and Its Implications

Placental production of human chorionic gonadotrophin α and β subunits in early pregnancy as evidenced in fluid from the exocoelomic cavity

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