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Test Code TTBS Testosterone, Total and Bioavailable, Serum

Reporting Name

Testosterone, Total and Bioavail, S

Useful For

Testosterone, Total:

-Evaluation of men with symptoms or signs of possible hypogonadism, such as loss of libido, erectile dysfunction, gynecomastia, osteoporosis, infertility

-Evaluation of boys with delayed or precocious puberty

-Monitoring testosterone replacement therapy

-Monitoring antiandrogen therapy (eg, used in prostate cancer, precocious puberty, treatment of idiopathic hirsutism, male-to-female transgender disorders)

-Evaluation of women with hirsutism, virilization, and oligo-amenorrhea

-Evaluation of women with symptoms or signs of possible testosterone deficiency

-Evaluation of infants with ambiguous genitalia or virilization

-Diagnosis of androgen-secreting tumors

 

Testosterone, Total and Bioavailable

-This is the recommended second-level test for suspected increases or decreases in physiologically active testosterone

-Assessment of androgen status in cases with suspected or known sex hormone-binding globulin binding abnormalities

-Assessment of functional circulating testosterone in early pubertal boys and older men

-Assessment of functional circulating testosterone in women with symptoms or signs of hyperandrogenism but normal total testosterone levels

-Monitoring of testosterone therapy or antiandrogen therapy in older men and in females

Profile Information

Test ID Reporting Name Available Separately Always Performed
BATS Testosterone, Bioavailable, S No Yes
TTST Testosterone, Total, S Yes Yes

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 1 mL

Additional Information: Patient's age and sex are required.


Seattle Children's Hospital Note:

Collect 2.0 mL whole blood in a Red top.

Specimen Minimum Volume

0.6 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Frozen  60 days

Reference Values

TESTOSTERONE, TOTAL

Males

0-5 months: 75-400 ng/dL

6 months-9 years: <7-20 ng/dL

10-11 years: <7-130 ng/dL

12-13 years: <7-800 ng/dL

14 years: <7-1,200 ng/dL

15-16 years: 100-1,200 ng/dL

17-18 years: 300-1,200 ng/dL

≥19 years: 240-950 ng/dL

Tanner Stages* 

I (prepubertal): <7-20

II: 8-66

III: 26-800

IV: 85-1,200      

V (young adult): 300-950

 

Females           

0-5 months: 20-80 ng/dL

6 months-9 years: <7-20 ng/dL

10-11 years: <7-44 ng/dL

12-16 years: <7-75 ng/dL

17-18 years: 20-75 ng/dL

≥19 years: 8-60 ng/dL

Tanner Stages*

I (prepubertal): <7-20

II: <7-47

III: 17-75

IV: 20-75

V (young adult): 12-60

 

*Puberty onset (transition from Tanner stage I to Tanner stage II) occurs for boys at a median age of 11.5 (±2) years and for girls at a median age of 10.5 (±2) years. There is evidence that it may occur up to 1 year earlier in obese girls and in African American girls. For boys, there is no definite proven relationship between puberty onset and body weight or ethnic origin. Progression through Tanner stages is variable. Tanner stage V (young adult) should be reached by age 18.

 

TESTOSTERONE, BIOAVAILABLE

Males

≤19 years: not established

20-29 years: 83-257 ng/dL

30-39 years: 72-235 ng/dL

40-49 years: 61-213 ng/dL

50-59 years: 50-190 ng/dL

60-69 years: 40-168 ng/dL

≥70 years: not established

Females (non-oophorectomized)

≤19 years: not established

20-50 years (on oral estrogen): 0.8-4.0 ng/dL

20-50 years (not on oral estrogen): 0.8-10 ng/dL

>50 years: not established

Day(s) and Time(s) Performed

Monday through Friday

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

84403-Testosterone, total

84410-Testosterone, bioavailable

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TTBS Testosterone, Total and Bioavail, S In Process

 

Result ID Test Result Name Result LOINC Value
82978 Testosterone, Bioavailable, S 2990-0
8533 Testosterone, Total, S 2986-8

Method Description

Testosterone, Bioavailable:

The method is based on the differential precipitation of sex hormone-binding globulin (SHBG) by ammonium sulfate following equilibration of the serum specimen and tracer amounts of tritium-labeled testosterone. The results are expressed as the percent of testosterone free or albumin bound (not precipitated with SHBG) compared to an albumin standard. The product of this percentage and the total testosterone measurement is the total bioavailable testosterone.(Wheeler MJ: The determination of bio-available testosterone. Ann Clin Biochem 1995;32:345-357)

 

Testosterone, Total:

Deuterated stable isotope (d3-testosterone) is added to a 0.2 mL serum sample as internal standard. Protein is precipitated from the mixture by the addition of acetonitrile. The testosterone and internal standard are extracted from the resulting supernatant by an online extraction utilizing high-throughput liquid chromatography (HTLC). This is followed by conventional liquid chromatography and analysis on a tandem mass spectrometer equipped with a heated nebulizer ion source.(Wang C, Catlin DH, Demers LM, et al: Measurement of total testosterone in adult men: comparison of current laboratory methods versus liquid chromatography-tandem mass spectrometry. J Clin Endocrinol Metab 2004;89:534-543; Taieb J, Mathian B, Millot F, 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)

Reject Due To

Hemolysis

Mild OK; Gross reject

Lipemia

Mild OK; Gross OK

Icterus

Mild OK; Gross OK

Other

NA

Method Name

TTST: Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

BATS: Differential Precipitation