TSH Antibody Test
This test measures TSH autoantibodies in a blood sample. It is described as useful when a serum TSH level appears discordant with clinical findings or other thyroid test results.
About this test
TSH autoantibodies can bind TSH to form a larger molecule known as macro-TSH, which has low biological activity but can interfere with standard TSH immunoassays. The test is measured by radioimmunoassay on a serum sample, and a positive result offers one possible explanation when a TSH value does not match the clinical picture or other thyroid results, such as a markedly elevated TSH alongside normal free triiodothyronine and free thyroxine levels.
Test details
| Collection | Quest patient service center |
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Quest resources
Additional details
What this test looks at
The test reports one value: the level of TSH autoantibody activity in serum. Because these antibodies can interfere with routine TSH assays, a clinician reads this result alongside pertinent history, physical examination findings and other thyroid test results, since other factors, such as interfering substances or subclinical hypothyroidism, can also produce a discordant TSH.
This test isn't part of the Celio Health store at the moment, so it can't be ordered or requested here. The test menu lists everything that can.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures TSH autoantibody activity in a serum sample, using radioimmunoassay.
How is the sample collected?
The test uses a serum sample from a routine blood draw.
Do I need to prepare for this test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
When is this test used?
It may be used when a serum TSH level is discordant with clinical findings or other thyroid results, to help determine whether TSH autoantibodies are a contributing factor.
What is macro-TSH?
Macro-TSH is a larger molecule formed when TSH autoantibodies bind TSH. It has low biological activity but can interfere with how standard TSH immunoassays read a sample.