Clinical use
Some pituitary macroadenomas may secrete only alpha subunit (ASU) making this a diagnostically useful test.Decreasing levels following surgery or radiotherapy can be useful in patient management. ASU measurement may also find a use in the differential diagnosis of TSH-secreting pituitary tumour versus thyroid hormone resistance.
Background
The glycoprotein hormones TSH, LH, FSH and HCG are composed of an alpha and beta subunit – the former is common to all these hormones. ASU is normally secreted as the free hormone as well as in combination with the glycoprotein hormone beta subunit.
Patient preparation
None required
Specimen requirements
Serum: Plain red topped tube preferred but can use an SST sample
Turnaround time
4 weeks
Additional Information
Please send clinical details including results of other pituitary hormone tests.
Referred test
Referred test
Location
Selly Oak Hospital