Preferred Sample Type
Suitable Specimen Types
- Serum
Specimen Transport
First Class Post
Sample Processing in Laboratory
No special requirements
Sample Preparation
Centrifuge and separate serum
Turnaround Time
3 weeksSample Stability
4ºC
Alpha Subunits (ASU)
General Information
The Alpha subunit of glycoprotein hormones is a peptide encoded by a gene found on chromosome 6. It serves as the alpha protein subunit for the following four hormones:
*Human chorionic gonadotropin (HCG)
*Follicle-stimulating hormone (FSH)
*Luteinizing hormone (LH)
*Thyroid stimulating hormone (TSH)
The beta subunits are unique and responsible for the biological and immunological specificity of the intact hormones.
Levels of free alpha subunit increase during normal pregnancy.
Measurement of free alpha subunit can be of clinical utility in the assessment of abnormal pregnancy, gestational trophoblastic disease, and some nontrophoblastic malignancies.
Elevated concentrations of alpha subunit have been associated with testicular cancer, pituitary adenomas, and malignant endocrine gastroenteropancreatic tumors, including Zollinger-Ellison syndrome.
Patient Preparation
None
Notes
Please send clinical details including results of other pituitary hormone tests.
Reference Range
- Adult males and pre-menopausal females: <1.0 IU/L
- Post-menopausal or mid-cycle females: <3.0 IU/L
Pregnancy - there is a 0.1% cross reaction with hCG resulting in very high ASU results in pregnancy.
Results should be interpreted along with the serum LH, FSH and TSH results and renal function tests.
Source of Reference Range
Provided by reference laboratorySpecifications
- EQA Scheme?: Yes
-
EQA Status:
No EQA Scheme - sample exchange in place