Alpha Subunit

Test Code
8658


CPT Codes
83520

Includes
This test measures the alpha subunit that is common to LH, FSH, TSH and hCG. These hormones are comprised of identical alpha subunits and unique beta subunits that confer biological specificity.


Preferred Specimen
1 mL serum


Minimum Volume
0.5 mL


Transport Container
Plastic screw-cap vial


Transport Temperature
Room temperature


Specimen Stability
Room temperature: 7 days
Refrigerated: 10 days
Frozen: 28 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly icteric • Plasma


Methodology
Electrochemiluminescence (ECLIA)

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Set up: Tues, Fri; Report available: 4-11 days


Reference Range
Males0.1-0.5 ng/mL
Premenopausal Females0.1-0.6 ng/mL
Postmenopausal Females0.1-1.5 ng/mL
Pregnancy (1st and 2nd Trimesters)35.0-186.0 ng/mL
Hypothyroidism0.2-3.2 ng/mL

This test measures the free alpha subunit that is common to LH, FSH, TSH and hCG. These hormones are comprised of identical alpha subunits and unique beta subunits that confer biological specificity.


Clinical Significance
This assay is useful in the diagnosis and management of various pituitary, placental, pancreatic and hCG-producing tumors. The assay can also be useful for investigations where alpha subunit is increased under various physiological stimuli, e.g., GnRH stimulation and TRH stimulation tests.


Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.