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Test Code LAB173 Testosterone, Total and Free, Serum

Reporting Name

Testosterone, Total and Free, S
Seattle Children's Hospital Note:

SCH Clinical System Name: Testosterone, Free + Total

Useful For

Alternative, 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 female patients


Ordering Guidance


This is a second-level test for suspected increases or decreases in physiologically active testosterone. The preferred test for assessment of active testosterone is TTBS / Testosterone, Total and Bioavailable, Serum.



Necessary Information


Patient's age and sex are required.



Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Red top (serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 2.5 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial


Seattle Children's Hospital Note:

Collect 5.0 mL whole blood in Red Top.

Specimen Type

Serum Red

Specimen Minimum Volume

1 mL

Specimen Stability Information

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

Day(s) Performed

Monday through Saturday

Seattle Children's Hospital Note:

TAT: 5 - 7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Method Name

FRTST: Equilibrium Dialysis/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

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

Method Description

Free Testosterone:

This method utilizes equilibrium dialysis to analyze and determine the host serum’s binding capacity for testosterone. Patient sample is placed inside a dialysis well that is immersed in dialysis buffer. The sample is dialyzed. During buffered dialysis, any testosterone that is unbound to sex hormone-binding globulin or albumin is free to pass through the semi-permeable dialysis membrane, while testosterone molecules bound to the binding proteins will be held inside the membrane. After dialysis, the buffered dialysate is analyzed for free testosterone by liquid chromatography tandem mass spectrometry (LC-MS/MS) with stable isotope (testosterone-[13]C3) after derivatization.(Unpublished Mayo method)

 

Total Testosterone:

Deuterated stable isotope (d3-testosterone) is added to a serum sample as internal standard. Protein is precipitated from the mixture. The testosterone and internal standard are extracted from the resulting supernatant by an on-line extraction utilizing high-throughput liquid chromatography. This is followed by conventional liquid chromatography and analysis on a tandem mass spectrometer equipped with a heated nebulizer ion source. Epitestosterone does not interfere with this LC-MS/MS method for total testosterone.(Unpublished Mayo method)

Reference Values

TESTOSTERONE, FREE

Males (adult):

20-<25 years: 5.25-20.7 ng/dL

25-<30 years: 5.05-19.8 ng/dL

30-<35 years: 4.85-19.0 ng/dL

35-<40 years: 4.65-18.1 ng/dL

40-<45 years: 4.46-17.1 ng/dL

45-<50 years: 4.26-16.4 ng/dL

50-<55 years: 4.06-15.6 ng/dL

55-<60 years: 3.87-14.7 ng/dL

60-<65 years: 3.67-13.9 ng/dL

65-<70 years: 3.47-13.0 ng/dL

70-<75 years: 3.28-12.2 ng/dL

75-<80 years: 3.08-11.3 ng/dL

80-<85 years: 2.88-10.5 ng/dL

85-<90 years: 2.69-9.61 ng/dL

90-<95 years: 2.49-8.76 ng/dL

95-100+ years: 2.29-7.91 ng/dL

 

Males (children):

<1 year: Term infants

1-15 days: 0.20-3.10 ng/dL*

16 days-1 year: Values decrease gradually from newborn (0.20-3.10 ng/dL) to prepubertal levels

*Forest MG, Cathiard AM, Bertrand JA. Total and unbound testosterone levels in the newborn and in normal and hypogonadal children: use of a sensitive radioimmunoassay for testosterone. J Clin Endocrinol Metab. 1973;36(6):1132-1142

 

1-8 years: <0.13 ng/dL

9 years: <0.13-0.45 ng/dL

10 years: <0.13-1.26 ng/dL

11 years: <0.13-5.52 ng/dL

12 years: <0.13-9.28 ng/dL

13 years: <0.13-12.6 ng/dL

14 years: 0.48-15.3 ng/dL

15 years: 1.62-17.7 ng/dL

16 years: 2.93-19.5 ng/dL

17 years: 4.28-20.9 ng/dL

18 years: 5.40-21.8 ng/dL

19 years: 5.36-21.2 ng/dL

 

Females (adult):

20-<25 years: <0.13-1.08 ng/dL

25-<30 years: <0.13-1.06 ng/dL

30-<35 years: <0.13-1.03 ng/dL

35-<40 years: <0.13-1.00 ng/dL

40-<45 years: <0.13-0.98 ng/dL

45-<50 years: <0.13-0.95 ng/dL

50-<55 years: <0.13-0.92 ng/dL

55-<60 years: <0.13-0.90 ng/dL

60-<65 years: <0.13-0.87 ng/dL

65-<70 years: <0.13-0.84 ng/dL

70-<75 years: <0.13-0.82 ng/dL

75-<80 years: <0.13-0.79 ng/dL

80-<85 years: <0.13-0.76 ng/dL

85-<90 years: <0.13-0.73 ng/dL

90-<95 years: <0.13-0.71 ng/dL

95-100+ years: <0.13-0.68 ng/dL

 

Females (children):

<1 year: Term infants

1-15 days: <0.13-0.25 ng/dL*

16 days-1 year: Values decrease gradually from newborn (<0.13-0.25 ng/dL) to prepubertal levels

*Forest MG, Cathiard AM, Bertrand JA. Total and unbound testosterone levels in the newborn and in normal and hypogonadal children: use of a sensitive radioimmunoassay for testosterone. J Clin Endocrinol Metab. 1973;36(6):1132-1142

 

1-4 years: <0.13 ng/dL

5 years: <0.13 ng/dL

6 years: <0.14 ng/dL

7 years: <0.13-0.23 ng/dL

8 years: <0.13-0.34 ng/dL

9 years: <0.13-0.46 ng/dL

10 years: <0.13-0.59 ng/dL

11 years: <0.13-0.72 ng/dL

12 years: <0.13-0.84 ng/dL

13 years: <0.13-0.96 ng/dL

14 years: <0.13-1.06 ng/dL

15-18 years: <0.13-1.09 ng/dL

19 years: <0.13-1.08 ng/dL

 

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.

Test Classification

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

CPT Code Information

84402

84403

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TGRP Testosterone, Total and Free, S 58952-3

 

Result ID Test Result Name Result LOINC Value
3631 Testosterone Free 2991-8
8533 Testosterone, Total, S 2986-8

Profile Information

Test ID Reporting Name Available Separately Always Performed
FRTST Testosterone, Free, S No Yes
TTST Testosterone, Total, S Yes Yes

Report Available

3 to 8 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Forms

If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.

Special Instructions