Human Chorionic Gonadotropin (hCG), β-Subunit, Quantitative, Serum

Human Chorionic Gonadotropin(hCG), β-Subunit, Quantitative, Serum

CPT Test code: 84702

Specimen:

Serum

Volume:

0.8 mL

Minimum Volume:

0.3 mL (Note: This volume does not allow for repeat testing.)

Container:

Red-top tube or gel-barrier tube

Special Instructions:

Values obtained with different assay methods should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient’s course of therapy. This procedure does not provide serial monitoring; it is intended for one-time use only. If serial monitoring is required, please use the serial monitoring number 480038 to order.

Collection:

If a red-top tube is used, transfer separated serum to a plastic transport tube.

Storage Instructions:

Refrigerate

Causes for Rejection:

Citrate plasma specimen; improper labeling

Reference Interval:

	Range
Weeks of pregnancy is defined as completed weeks beginning with the start of the last menstruation phase.
Male	0-3
Female
nonpregnant	0-5
postmenopausal	0-8
pregnant
Weeks Gestation
3	6-71
4	10-750
5	217-7138
6	158-31,795
7	3697-163,563
8	32,065-149,571
9	63,803-151,410
10	46,509-186,977
12	27,832-210,612
14	13,950-62,530
15	12,039-70,971
16	9040-56,451
17	8175-55,868
18	8099-58,176

Use:

This test can be used for the early detection of and on-going monitoring of pregnancy. Determine the presence of hCG in patients with gestational trophoblastic disease; evaluate and monitor male patients with testicular tumors; follow up molar pregnancy. The quantitative hCG assay should be used for nonroutine detection of hCG (eg, ectopic pregnancy, threatened abortions, miscarriages, or very early pregnancy).

Limitations:

In patients receiving therapy with high biotin doses (ie, >5 mg/day), no sample should be taken until at least eight hours after the last biotin administration.¹ As with all tests containing monoclonal mouse antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or have received them for diagnostic purposes.¹ In rare cases, interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur.¹ The test contains additives, which minimize these effects.

Additional Information:

Similarly to LH, FSH, and TSH, human chorionic gonadotropin (hCG) is a member of the glycoprotein family and consists of two subunits (α and β chains) that are associated to the intact hormone. The α chains in all four of these glycoprotein hormones are virtually identical, whereas the β chains have greatly differing structures and are responsible for the respective specific hormonal functions.

hCG is produced in the placenta during pregnancy. In nonpregnant women, it can also be produced by tumors of the trophoblast, germ cell tumors with trophoblastic components, and some nontrophoblastic tumors.

Human chorionic gonadotropin consists of a number of isohormones with differing molecular size. The biological action of hCG serves to maintain the corpus luteum during pregnancy. It also influences steroid production. The serum of pregnant women contains mainly intact hCG.

Measurement of the hCG concentration permits the diagnosis of pregnancy just one week after conception. The determination of hCG in the first trimester of pregnancy is of particular importance. Elevated values here serve as an indication of chorionic carcinoma, hydatiform mole, or multiple pregnancy. Depressed values indicate threatening or missed abortion, ectopic pregnancy, gestosis, or intrauterine death.

Elevated hCG concentrations not associated with pregnancy are found in patients with other diseases, such as tumors of the germ cells, ovaries, bladder, pancreas, stomach, lungs, and liver.^2,3

Footnotes:

1. Human Chorionic Gonadotropin (hCG) on Elecsys 1010/2010 and Modular Analytics E170, package insert 2007-09, V 11, Indianapolis, Ind: Roche Diagnostics; 2007.

2. Sturgeon CM, McAllister EJ. Analysis of hCG: Clinical applications and assay requirements. Ann Clin Biochem. 1998 Jul; 35(Pt 4):460-491.PubMed 9681050

3. Marcillac I, Troalen F, Bidart JM, et al. Free human chorionic gonadotropin beta subunit in gonadal and nongonadal neoplasms. Cancer Res. 1992 Jul 15; 52(14):3901-3907.PubMed 1377600

References:

Deligdisch L, Driscoll SG, Goldstein DP. Gestational trophoblastic neoplasms: Morphologic correlates of therapeutic response. Am J Obstet Gynecol. 1978 Apr 1; 130(7):801-806. PubMed 205134

Hoermann R, Berger P, Spoettl G, et al. Immunological recognition and clinical significance of nicked human chorionic gonadotropin in testicular cancer. Clin Chem. 1994 Dec; 40(12):2306-2312.PubMed 7527309

Khazaeli MB, Buchina ES, Pattillo RA, Soong SJ, Hatch KD. Radioimmunoassay of free beta-subunit of human chorionic gonadotropin in diagnosis of high-risk and low-risk gestational trophoblastic disease. Am J Obstet Gynecol. 1989 Feb; 160(2):444-449. PubMed 2464935

Morinaga S, Ojima M, Sasano N. Human chorionic gonadotropin and alpha-fetoprotein in testicular germ cell tumors. An immunohistochemical study in comparison with tissue concentrations. Cancer. 1983 Oct 1; 52(7):1281-1289. PubMed 6192898

Runnebaum B, Rabe T. Gynäkologische Endokrinologie, Grundlagen, Physiologie, Pathologie, Prophylaxe, Diagnostik, Therapie. Berlin: Springer Verlag; 1987; 8:43; 489-541.

Schwarz S, Berger P, Wick G. The antigenic surface of human chorionic gonadotropin as mapped by murine monoclonal antibodies. Endocrinology. 1986 Jan; 118(1):189-197.PubMed 2416550

Thomas CM, Reijnders FJ, Segers MF, Doesburg WH, Rolland R. Human choriogonadotropin (hCG): comparisons between determinations of intact hCG, free hCG beta-subunit, and “total” hCG + beta in serum during the first half of high-risk pregnancy. Clin Chem. 1990 Apr; 36(4):651-655.

Tyrey L. Human chorionic gonadotropin assays and their uses. Obstet Gynecol Clin North Am. 1988 Sep; 15(3):457-475.PubMed 2852329