Test Details
Methodology
Immunochemiluminometric assay (ICMA)
Result Turnaround Time
6 - 10 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Tumor marker
Footnotes
Custom Additional Information
The α-subunits of human pituitary glycoprotein hormones TSH, FSH, LH, and the placental hormone hCG have similar amino sequences and are immunologically indistinguishable.1 The β-subunits are unique and responsible for the biological and immunological specificity of the intact hormones. Levels of free α-subunit increase during normal pregnancy.2 Measurement of free α-subunit can be of clinical utility in the assessment of abnormal pregnancy, gestational trophoblastic disease, and some nontrophoblastic malignancies.3,4 Elevated concentrations of α subunit have been associated with testicular cancer,5 pituitary adenomas,6 and malignant endocrine gastroenteropancreatic tumors, including Zollinger-Ellison syndrome.7,8
Specimen Requirements
Specimen
Serum, frozen
Volume
1 mL
Minimum Volume
0.25 mL (Note: This volume does not allow for repeat testing.)
Container
Serum from gel-barrier tube, serum from red-top tube, or serum from transfer tube
Collection Instructions
Transfer the serum into a Labcorp PP transpak frozen purple tube with screw cap (Labcorp No. 49482). Freeze immediately and maintain frozen until tested. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 1 day |
Refrigerated | 1 day |
Frozen | 200 days |
Reference Range
• Male:
− 20 to 44 years: <0.55 ng/mL
− 45 to 54 years: <0.86 ng/mL
− 55 to 64 years: <1.37 ng/mL
− 65 to 94 years: <2.13 ng/mL
• Female:
− 20 to 44 years (premenopausal): <1.02 ng/mL
− 45 to 59 years (perimenopausal): <2.34 ng/mL
− 60 to 99 years (postmenopausal): <3.56 ng/mL
Storage Instructions
Freeze.
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 140269 | Alpha Subunit (Free) | 30316-4 | 140271 | Alpha Subunit (Free) | ng/mL | 30316-4 |
| Order Code | 140269 | |||||
| Order Code Name | Alpha Subunit (Free) | |||||
| Order Loinc | 30316-4 | |||||
| Result Code | 140271 | |||||
| Result Code Name | Alpha Subunit (Free) | |||||
| UofM | ng/mL | |||||
| Result LOINC | 30316-4 |