Test Directory

• Adjunct in the diagnosis of pituitary tumors
• As part of the follow-up of treated pituitary tumor patients
• Differential diagnosis of thyrotropin-secreting pituitary tumor versus thyroid hormone resistance
• Differential diagnosis of constitutional delay of puberty versus hypogonadotrophic hypogonadism

Specimen Type: Serum

Preferred Collection Container: Gold Top, Serum Separator

Alternate Collection Container: Red Top, Plain

Desired Specimen Volume: 1 mL

1. Collect a gold top, serum separator tube via venipuncture.

1. Separate serum from cells.
2. Transfer 1 mL of serum to a clear aliquot tube (screw cap).

Transport to the laboratory frozen. 

• Gross hemolysis

See patient report.

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 kidney 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 thyrotropin (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 in serum free alpha-subunit levels.

Pregnancy is associated with very substantial, physiological elevations in serum free alpha-subunit levels, paralleling chorionic gonadotropin (hCG) secretion. This test should not be ordered on pregnant patients.

Thyrotropin-releasing hormone and gonadotropin releasing hormone testing are not performed in the laboratory, but in specialized clinical testing units under the supervision of a physician

• Alpha Glycoprotein Subunit
• Alpha Subunit, HCG
• Alpha-HCG (Human Chorionic Gonadotropin)
• Alpha-PGH (Pituitary Glycoprotein Hormone)
• Alpha-Subunit of Pituitary Glycoprotein Hormones (Alpha-PGH), Serum
• Chorionic Gonadotropins, Alpha-Subunit
• Glycoprotein Subunit
• HCG, Alpha Subunit
• Hormone, Alpha-Subunit
• PGH (Pituitary Glycoprotein Hormone)
• Pituitary Glycoprotein Alpha Subunit
• Pituitary Gonadotropins, Alpha-Subunit