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| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Testosterone, Total Males (Adult), Immunoassay
Test Code19958
CPT Codes
84403
Includes
Note: When requesting Total Testosterone for pediatric and female patients please refer to Testosterone, Total, LC/MS/MS, test code: 15983.
Preferred Specimen
1 mL serum
Patient Preparation
Due to changes in testosterone levels throughout the day, two morning (8-10 AM) specimens obtained on different days are recommended by The Endocrine Society for screening.
Minimum Volume
0.5 mL
Instructions
Specify age and sex on test request form.
Dietary supplements containing biotin may interfere in assays and may skew results to be either falsely high or falsely low. For patients receiving the recommended daily doses of biotin, draw samples at least 8 hours following the last biotin supplementation. For patients on mega-doses of biotin supplements, draw samples at least 72 hours following the last biotin supplementation.
Note: This assay should be performed on adult (> or = 18 years) males.
Dietary supplements containing biotin may interfere in assays and may skew results to be either falsely high or falsely low. For patients receiving the recommended daily doses of biotin, draw samples at least 8 hours following the last biotin supplementation. For patients on mega-doses of biotin supplements, draw samples at least 72 hours following the last biotin supplementation.
Note: This assay should be performed on adult (> or = 18 years) males.
Transport Container
Plastic screw-cap vial
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 5 days
Refrigerated: 7 days
Frozen: 21 days
Refrigerated: 7 days
Frozen: 21 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross icteric
Methodology
Immunoassay (IA)
Setup Schedule
Set up: Mon-Sat; Report available: Next day
Limitations
Immunoassay does not provide sufficient sensitivity in detecting low concentrations among non-adults and women.
Reference Range
| Adult Male | 250-827 ng/dL |
Current guidelines from many professional societies, including the Endocrine Society and the Menopause Society recommend Liquid Chromatography - Mass Spectrometry (LCMS) testing (TC 15983) for women, children (< 18 years), and men with hypogonadism. LCMS is more accurate and less prone to interfering substances (such as biotin) when low levels of testosterone are suspected. Immunoassays are useful for routine screening or tracking of testosterone levels in adult patients where diagnoses are not being made and testosterone levels are expected to be stable. No reference intervals have been established for female patients or any patient under the age of 18.
Clinical Significance
Testosterone circulates almost entirely bound to transport proteins: Normally less than 1-2% is free. The principal transport protein for testosterone is known as sex hormone binding globulin (SHBG) or testosterone-estradiol binding globulin (TeBG). Testosterone measurements are used to assess erectile dysfunction, infertility, gynecomastia, and osteoporosis and to assess hormone replacement therapy.
