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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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FSH (FOLLICLE STIMULATING HORMONE)

Item Value
Available Stat? No
Test code FSH
Performed by? Chemistry
Sendout? no
Price range $$$
In House Availability Mon - Fri
Sat - Sun (12 pm - 8 pm)
Principle The Siemens Centaur assay is a two-site sandwich immunoassay using direct Chemiluminometric technology.
Interpretation Follicle Stimulating Hormone is a glycoprotein hormone secreted by the anterior pituitary gland that stimulates gonadal development, production of steroidal sex hormones, and gametogenesis. In the post-pubertal female, gonadotrophins (LH and FSH) peak at midcycle, responsible in part for elevations in both progesterone and estrogen during the latter half of the cycle. Elevated levels of FSH are seen in primary amenorrhea due to gonadal dysgenesis, such as Turner's syndrome.

After menopause, FSH levels rise but may fluctuate widely over time. In males, elevated FSH levels are seen with primary hypogonadism, such as with Kleinfelter's Syndrome, whereas pituitary causes of hypogonadism are associated with decreased LH/FSH levels.
Container type gold top gel tube
Amount to Collect 2 mL
Collection Instructions Plasma samples cannot be assayed.
Sample type Blood
Normal range IU/L (mIU/mL)*
Male: 1.4 - 18.1
Adult Female: Follicular: 2.5-10.2
Ovulatory: 3.4-33.4
Luteal: 1.5-9.1
Post Menopausal: 23.0-116.3

*Units are referenced to the W.H.O. Second International Standard (2nd IS) 94/632 for FSH.

Synonyms Follicle Stimulating Hormone;
Stability Serum stable 48 hrs at 2-8°C; 1 month frozen at -20°C.
Interferences 1. Oral contraceptives or estrogen replacement drugs that contain estrogen and/or progesterone may cause a physiologic decrease in serum levels of FSH.

2. Auto- (rheumatoid factor) and heterophile antibodies in human serum can react with reagent immunoglobulins, interfering with in vitro immunoassays. Patients routinely exposed to animals or to animal serum products can be prone to this interference. Anomalous values may be observed. The most common, although not exclusive, interference seen in immunometric ("two-site," "sandwich") assays is a spuriously high value. Results inconsistent with clinical findings or previous laboratory values can be investigated by the laboratory for this phenomenon. Call the Clinical Chemistry Laboratory Medicine Resident (x65527, pager 415-443-2311).

3. A paradoxical, false low result may rarely occur when patient samples with extremely high concentrations of peptide/protein analytes (e.g. AFP, hCG, PSA, etc.) are measured by immunometric ("two-site," "sandwich") assays. For example, a true value of 3,000,000 U/L could be reported as < 5 or 21 U/L. This phenomenon is called the "high dose hook effect." Results inconsistent with clinical findings or previous laboratory values can be investigated by the laboratory for this phenomenon. Call the Clinical Chemistry Laboratory Medicine Resident (x65527, pager 415-443-2311).
References 1. Bayer 111741 Rev. C, 5/2000. Siemens Medical Solutions Diagnostics, Malvern, PA.

2. Tietz, N.W. Textbook of Clinical Chemistry and Molecular Diagnosis, ed. 4. St. Louis, MO: Elsevier Saunders, 1984-1988; 2006.

3. Warren MP. Evaluation of Secondary Amenorrhea. J of Clinical Endocrinol and Metabolism 1996;81:437-442.
CPT coding 83001
Last Updated 10/24/2012 11:23:50 AM
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