Alpha Subunit
Test Mnemonic
ALPSUB
CPT Codes
- 82397 - QTY (1)
LOINC ®
14170-5
Aliases
- Alpha Subunit Pituitary Tumor Marker
Performing Laboratory
Mayo Clinic Dpt of Lab Med & Pathology
FDA Category
Laboratory Developed Test
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Serum | SST (Gold) | Frozen | Centrifuge and transfer into standard plastic aliquot tube. |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Serum | No additive (Red) |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 0.35 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | Unacceptable |
| Refrigerated | 7 days |
| Frozen | 3 months |
Days Performed
Wed
Turnaround Time
2 - 8 days
Methodology
| Name | Description |
|---|---|
| Immunochemiluminescent Assay |
Reference Range
| Alpha Subunit | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Days | 5 Days | Normal | < 51 | ng/mL | 6 Days | 7 Days | Normal | < 11 | ng/mL | 1 Weeks | 12 Weeks | Normal | < 11 | ng/mL | 3 Months | 12 Months | Normal | < 1.3 | ng/mL | 1 Years | 17 Years | Normal | < 1.3 | ng/mL | Normal | Tanner stage 2 - 4: < 1.3 | ng/mL | Male | 18 Years | 99 Years | Normal | < 0.6 | ng/mL | Female | Normal | Premenopausal: < 1.3 | ng/mL | Female | Normal | Postmenopausal: < 1.9 | ng/mL |
Special Info
False positive elevations in serum free alpha-subunit levels may be seen in some women if blood specimens are drawn within 24 hours of ovulation. Patients with end-stage renal failure may have serum free alpha-subunit concentrations of up to 6 times the upper limit of reference range. Elevated alpha-subunit results on patients with elevated TSH should be interpreted with caution due to TSH cross-reactivity with the assay. Assisted reproduction involving ovarian hyperstimulation or in vitro fertilization may be associated with the elevation of serum free alpha-subunit levels. Pregnancy is associated with substantial physiological elevations in serum free alpha-subunit levels, paralleling hCG secretion. This test should not be ordered on pregnant patients. Grossly hemolyzed specimens will be rejected.
Clinical Info
The 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.