This Article Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by KATO, Y. Articles by BRAUNSTEIN, G. D. Search for Related Content PubMed PubMed Citation Articles by KATO, Y. Articles by BRAUNSTEIN, G. D.

β-Core Fragment Is a Major Form of Immunoreactive Urinary Chorionic Gonadotropin in Human Pregnancy^*

Department of Medicine, Cedars-Sinai Medical Center- University of California School of Medicine Los Angeles, California 90048

Address requests for reprints to: Glenn D. Braunstein, M.D., Department of Medicine, Room 2119, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, California 90048.

A small mol wt fragment of the β-subunit of hCG (β-core fragment) is present in the urine, but not the serum, of pregnant women. We evaluated the relative proportions of this immunoreactive, but biologically inactive, fragment in urine from 15 women at different stages of pregnancy. Freshly voided urine was ultrafiltered and concentrated, and the molecular species of immunoreactive hCG were separated by Sephadex G-100 column chromatography. All urine samples contained the β-core fragment, which eluted after the a-subunit of hCG. This fragment lacked the carboxy-terminal epitope of hCG, was inactive as an in vitro bioassay, and adsorbed to Concanavalin-A. The β-core fragment was a major form the immunoreactive hCG in urine throughout pregnancy and accounted for over 90% of the immunoreactive hCG in urine from midpregnancy. The excretion pattern of the β-core fragment can account for the low biological to immunological ratio of urinary hCG that occurs at different stages of pregnancy

^* This work was supported by the Hertzog Foundation.

Received August 24, 1987.

This article has been cited by other articles:

				A. M. Gronowski and D. G. Grenache Characterization of the hCG Variants Recognized by Different hCG Immunoassays: An Important Step Toward Standardization of hCG Measurements Clin. Chem., August 1, 2009; 55(8): 1447 - 1449. [Full Text] [PDF]

				A. M. Gronowski, M. Cervinski, U.-H. Stenman, A. Woodworth, L. Ashby, and M. G. Scott False-Negative Results in Point-of-Care Qualitative Human Chorionic Gonadotropin (hCG) Devices Due to Excess hCG{beta} Core Fragment Clin. Chem., July 1, 2009; 55(7): 1389 - 1394. [Abstract] [Full Text] [PDF]

				R. McChesney, A. J. Wilcox, J. F. O'Connor, C. R. Weinberg, D. D. Baird, J. P. Schlatterer, D.R. McConnaughey, S. Birken, and R. E. Canfield Intact HCG, free HCG {beta} subunit and HCG {beta} core fragment: longitudinal patterns in urine during early pregnancy Hum. Reprod., April 1, 2005; 20(4): 928 - 935. [Abstract] [Full Text] [PDF]

				J. J. Hsu, K. Spencer, T. H. Hung, T's. T. Hsieh, and Y. K. Soong Second-trimester maternal urine human chorionic gonadotrophin {beta}-core fragment concentrations in Asian pregnancies with fetal chromosomal abnormalities Hum. Reprod., September 1, 1999; 14(9): 2381 - 2385. [Abstract] [Full Text] [PDF]

				C. Liu and L. D. Bowers Mass spectrometric characterization of nicked fragments of the {beta}-subunit of human chorionic gonadotropin Clin. Chem., July 1, 1997; 43(7): 1172 - 1181. [Abstract] [Full Text] [PDF]

				W. Feng, M. M. Matzuk, K. Mountjoy, E. Bedows, R. W. Ruddon, and I. Boime The Asparagine-linked Oligosaccharides of the Human Chorionic Gonadotropin [IMAGE] Subunit Facilitate Correct Disulfide Bond Pairing J. Biol. Chem., May 19, 1995; 270(20): 11851 - 11859. [Abstract] [Full Text] [PDF]