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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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Item Value
Available Stat? No
Test code TES
Performed by? Chemistry
Sendout? no
Price range $$$
In House Availability Monday - Friday
Principle The Siemens Centaur assay is a competitive immunoassay using direct chemiluminescent technology.
Interpretation Testosterone measurements have been used in newborns to aid in the differential diagnosis of ambiguous genitalia. In prepubertal males, elevated testosterone levels are found in both gonadotropin dependent (e.g., CNS tumors) and independent (e.g., adrenal tumors) precocious puberty. Testosterone determinations are used in evaluating hypogonadal and hypopituitary states in adolescents and adults, such as Klinefelter and Kallmann syndromes. In adults, testosterone levels are measured to diagnose male factor infertility. Common causes of elevated serum testosterone in females include polycystic ovaries, ovarian tumors, adrenal tumors and adrenal hyperplasia. Virilization and hirsutism in women are associated with endogeneous over-production of testosterone or administration of androgens.
Container type gold top gel tube
Amount to Collect 2 mL
Collection Instructions Plasma samples will not be assayed.
Sample type Blood
Normal range
Male 241 - 827 ng/dL 8.36 - 28.70 nmol/L
Female 14 - 76 ng/dL 0.49 - 2.64 nmol/L

Stability Serum is stable 48 hrs at 2-8°C,
6 months at -20°C.
Interferences 1. 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, spuriously low or high, may be observed. 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).

2. Testosterone concentrations measured by this assay on samples from women and children should be interpreted with caution. Two recent studies compared direct serum testosterone immunoassays with "gold standard" methods (gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry). Their results suggest that most direct immunoassays have high variability and a tendency to overestimate at testosterone concentrations that are typical for normal women and pre-pubertal children. For more information, call the Endocrine Fellow 719-9535 or the Clinical Chemistry Laboratory Medicine Resident (x65527, pager 415-443-2311).
References 1. Williams RH, ed: Textbook of Endocrinology, 9th Ed. WB Saunders Company, Philadelphia, PA, 1998.

2. Pesce AJ and Kaplan LA Eds: Methods in Clinical Chemistry. CV Mosby Co., St. Louis, MO, pp 266-269, 1978.

3. Tietz, N.W. Textbook of Clinical Chemistry and Molecular Diagnosis, ed. 4. St. Louis, MO: Elsevier Saunders, 2097; 2006.

4. Bayer 111751 Rev. G, 01/2001. Siemens Medical Solutions Diagnostics, Malvern, PA.

5. Wang C, et al. Measurement of total serum testosterone in adult men: Comparison of current laboratory methods versus liquid chromatography – Tandem mass spectrometry. J Clin Endocrinol Metab 2004; 89:534-543.

6. Taieb et al. Testosterone measured by 10 immunoassays and by isotope-dilution gas chromatography-mass spectrometry in sera from 116 men, women and children. Clin Chem 2003; 49: 1381-1395.
CPT coding 84403
Last Updated 6/18/2011 8:15:32 AM
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