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TESTOSTERONE,TOTAL WX
Test CodeTESTOSTERONE,TOTAL WX
Preferred Specimen
Serum in SST
Minimum Volume
1mL
Instructions
Remove the serum from clot or separator gel as soon as possible after complete clot formation, or plasma from red blood cells as soon as possible upon receipt.
Transport Temperature
Refrigerated 2-8ºc
Specimen Stability
Room Temp. 8 Hours
Refrigerated 7 days
Refrigerated 7 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
· heat-inactivated specimens
· pooled specimens
· grossly hemolyzed specimens
· specimens with obvious microbial contamination
Setup Schedule
Daily
Report Available
< 2 Days
Limitations
· Results should be used in conjunction with other data; e.g., symptoms, results of other tests, and clinical impressions.
· If the testosterone results are inconsistent with clinical evidence, additional testing is recommended.
· Specimens from patients who have received preparations of mouse monoclonal antibodies for diagnosis or therapy may contain human anti-mouse antibodies (HAMA). Such specimens may show either falsely elevated or depressed values when tested with assay kits such as Alinity i 2nd Generation Testosterone that employ mouse monoclonal antibodies. Additional information may be required for diagnosis.13, 14
· A strong interaction with D-(-)Norgestrel (1000 ng/mL), 19-nortestosterone (Nandrolone), Ethisterone, 11b-Hydroxytestosterone, and 11-Ketotestosterone was found. Do not use samples from patients receiving these compounds.
· Heterophilic 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, and anomalous values may be observed. Additional information may be required for diagnosis.15
· Samples positive for Rheumatoid Factor (RF), that were spiked to testosterone concentrations of 201.9 ng/dL and 700.8 ng/dL, had a mean percent recovery of 103.0% (range: 78.2 - 129.6%, n = 25) and 94.0% (range: 80.6 - 101.1%, n = 25), respectively.
· Samples positive for Heterophilic Antibodies, that were spiked to testosterone concentrations of 201.9 ng/dL and 700.8 ng/dL, had a mean percent recovery of 103.0% (range: 74.5 - 109.2%, n = 23) and 94.0% (range: 80.6 - 104.0%, n = 25), respectively.
Reference Range
| Gender | Reference range | Units |
| Male | 220 - 892 | ng/dl |
| Female | 9-55 | ng/dl |
Clinical Significance
Testosterone is regarded as the most important of the androgen steroids. In males, it is secreted by the Leydig and interstitial cells of the testes which are stimulated by luteinizing hormone (LH). Control of testosterone secretion is through a negative feedback loop to the hypothalamus where secretion of gonadotrophin-releasing hormone promotes synthesis and release of LH and follicle-stimulating hormone (FSH) from the anterior pituitary gland.
In females, testosterone is secreted by the follicular theca and interstitial cells of the ovaries and also produced by metabolism of adrenal androgens. The concentrations of testosterone are typically about 10-20 times lower for females than for males.
In the circulation, approximately 97% of testosterone is transported by proteins, most notably by binding to sex hormone-binding globulin (SHBG) with an affinity of approximately 109 Lmol-1.1 Testosterone is also weakly bound to albumin.
The Alinity i 2nd Generation Testosterone assay releases testosterone from binding proteins and measures total testosterone. Free testosterone can be calculated from the total testosterone, SHBG and albumin concentrations.2 The Free Androgen Index (FAI) may also be calculated (FAI = [Total Testosterone] / [SHBG]) and provides an index of free testosterone status. This ratio correlates well with both measured and calculated values of free testosterone and helps to discriminate subjects with excessive androgen activity from normal individuals.3, 4, 5
The concentration of testosterone in an individual fluctuates over 24 hours.6 The pulsatile release of LH in the night typically leads to a peak of testosterone concentration in the morning. Time of day, age, sex, puberty, pre- and post-menopause, and disease, all have an influence on testosterone concentration and should be considered in interpreting individual results.
In females, testosterone is secreted by the follicular theca and interstitial cells of the ovaries and also produced by metabolism of adrenal androgens. The concentrations of testosterone are typically about 10-20 times lower for females than for males.
In the circulation, approximately 97% of testosterone is transported by proteins, most notably by binding to sex hormone-binding globulin (SHBG) with an affinity of approximately 109 Lmol-1.1 Testosterone is also weakly bound to albumin.
The Alinity i 2nd Generation Testosterone assay releases testosterone from binding proteins and measures total testosterone. Free testosterone can be calculated from the total testosterone, SHBG and albumin concentrations.2 The Free Androgen Index (FAI) may also be calculated (FAI = [Total Testosterone] / [SHBG]) and provides an index of free testosterone status. This ratio correlates well with both measured and calculated values of free testosterone and helps to discriminate subjects with excessive androgen activity from normal individuals.3, 4, 5
The concentration of testosterone in an individual fluctuates over 24 hours.6 The pulsatile release of LH in the night typically leads to a peak of testosterone concentration in the morning. Time of day, age, sex, puberty, pre- and post-menopause, and disease, all have an influence on testosterone concentration and should be considered in interpreting individual results.
Performing Laboratory
Test performed at West Roxbury Chemistry Lab
Contact: Jonathan Dryjowicz-Burek 857-203-5418
Last Updated: March 10, 2025
