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Title: Relationship between blood and urine concentrations of intact human chorionic gonadotropin and its free subunits in early pregnancy

Abstract

Paired blood and urine samples were obtained from patients between the sixth and 14th weeks of normal pregnancy. The levels of intact human chorionic gonadotropin (hCG), and of the free alpha and beta subunits, were measured by specific radioimmunoassays. There was a close association between blood and urine levels of intact hCG and of the alpha subunit of hCG, but no relation between the levels of beta subunit in these sites. These findings suggest that the use of beta subunit assays may give discrepant results according to the fluid examined. By contrast, measurement of intact hCG appears to give similar results in blood and urine.

Authors:
; ; ; ;
Publication Date:
Research Org.:
St. Bartholomew's Hospital Medical College, London, England
OSTI Identifier:
6596188
Resource Type:
Journal Article
Resource Relation:
Journal Name: Obstet. Gynecol.; (United States); Journal Volume: 4
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; GONADOTROPINS; RADIOIMMUNOASSAY; BLOOD; PATIENTS; PREGNANCY; URINE; BIOLOGICAL MATERIALS; BIOLOGICAL WASTES; BODY FLUIDS; HORMONES; IMMUNOASSAY; IMMUNOLOGY; ISOTOPE APPLICATIONS; MATERIALS; PEPTIDE HORMONES; PITUITARY HORMONES; RADIOASSAY; RADIOIMMUNOLOGY; TRACER TECHNIQUES; WASTES 550601* -- Medicine-- Unsealed Radionuclides in Diagnostics

Citation Formats

Norman, R.J., Menabawey, M., Lowings, C., Buck, R.H., and Chard, T. Relationship between blood and urine concentrations of intact human chorionic gonadotropin and its free subunits in early pregnancy. United States: N. p., 1987. Web.
Norman, R.J., Menabawey, M., Lowings, C., Buck, R.H., & Chard, T. Relationship between blood and urine concentrations of intact human chorionic gonadotropin and its free subunits in early pregnancy. United States.
Norman, R.J., Menabawey, M., Lowings, C., Buck, R.H., and Chard, T. 1987. "Relationship between blood and urine concentrations of intact human chorionic gonadotropin and its free subunits in early pregnancy". United States. doi:.
@article{osti_6596188,
title = {Relationship between blood and urine concentrations of intact human chorionic gonadotropin and its free subunits in early pregnancy},
author = {Norman, R.J. and Menabawey, M. and Lowings, C. and Buck, R.H. and Chard, T.},
abstractNote = {Paired blood and urine samples were obtained from patients between the sixth and 14th weeks of normal pregnancy. The levels of intact human chorionic gonadotropin (hCG), and of the free alpha and beta subunits, were measured by specific radioimmunoassays. There was a close association between blood and urine levels of intact hCG and of the alpha subunit of hCG, but no relation between the levels of beta subunit in these sites. These findings suggest that the use of beta subunit assays may give discrepant results according to the fluid examined. By contrast, measurement of intact hCG appears to give similar results in blood and urine.},
doi = {},
journal = {Obstet. Gynecol.; (United States)},
number = ,
volume = 4,
place = {United States},
year = 1987,
month = 4
}
  • The radioreceptorassay of human chorionic gonadotropin (hCG), with a sensitivity of 50 pg or 3 mIU/ml of plasma, has provided almost 100 percent reliability in detecting pregnancy after the first missed cycle. This test may be performed within 1 hour and is ideally suited to the clinical detection of ectopic pregnancy, especially in patients who require immediate surgical intervention. Thirteen patients with suspected ectopic pregnancy were evaluated by the radioreceptorassay, one of whom was followed with four separate determinations. The results of the assay were subsequently compared with those of hemagglutination pregnancy tests, clinical symptoms, and pathologic findings. All ofmore » the patients were diagnosed accurately by the radioreceptorassay, even when hemagglutination tests yielded a false indication of pregnancy. By this assay, the hCG levels during ectopic pregnancies are generally lower than those found during a normal intrauterine pregnancy; in addition, pregnancy may be detected much earlier (prior to the rupture) than is possible by hemagglutination tests. Furthermore, the diagnosis of ectopic pregnancy may be excluded for patients admitted to the hospital with acute abdominal emergencies.« less
  • The value of RIAs that measure hCG levels in human urine has been limited principally because of cross-reactivity with human LH. Recently, antisera generated to antigenic determinants on the intact hCG..beta.. subunit and its carboxyl-terminal peptide have been shown to exhibit substantially reduced human LH cross-reactivity. To take maximal advantage of these antisera and to minimize interference by nonspecific substances in urine, a procedure for extracting and concentrating hCG from 24-h urine samples was developed. The procedure involves preparation of a standard kaolin-acetone urine concentrate and adsorption of the hCG in the concentrate to Concanavalin A covalently linked to agarosemore » for purification and subsequent RIA. In urine samples obtained from patients with gestational trophoblastic disease, there was a direct correlation between hCG levels measured by RIA and those estimated by mouse uterine weight bioassy. In individual subjects, hCG levels were determined in serum and urine obtained the same day. When hCG was clearly detectable in the serum at levels greater than 1 ng/ml, the quantity of hCG measured in the urine concentrate exceeded 500 ng/24 h. The concentrates prepared from the urine of normal persons contained an hCG-like glycoprotein substance with antigenic determinants similar to those of the carboxyl-terminal peptide of hCG..beta... As the range of hCG immunoreactivity measured in the urine concentrates of normal subjects was 6 to 52 ng/24 h, specific and sensitive detection of urinary hCG could be accomplished in patients whose sera contained hCG undetectable by conventional RIA. Partial purification and concentration of urinary hCG by this procedure with subsequent RIA provides a sensitive and reliable method for detecting hCG in urine.« less