Thyroglobulin Mass Spectrometry, Serum [A Test in Focus]

 

This new Mayo Clinic assay provides clinicians an accurate measurement of serum thyroglobulin in patients with known or suspected anti-thyroglobulin autoantibodies or heterophilic antibodies. View a quick overview of the test's details and a five-minute video interview with Dr. Stefan Grebe, which provides greater detail about this assay.

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  • Accurate measurement of serum thyroglobulin (Tg) in patients with known or suspected antithyroglobulin autoantibodies (TgAB) or heterophile antibodies (HAB)
  • Reflex testing of samples with previously unknown TgAB status that prove TgAB positive during immunoassay testing
  • Rarely, in patients without thyroid cancer to assist in the differential diagnosis of early phase silent thyroiditis versus Graves' disease (the mass spectrometry-based method would only be required if these patients have TgAB or HAB)
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When should I order this test

This test should be ordered to accurately measure serum thyroglobulin in patients with known or suspected anti-thyroglobulin autoantibodies or heterophilic antibodies.


Key points:

  • Serum thyroglobulin measurement is used to follow-up of patient with differentiated follicular cell-derived thyroid carcinoma after surgical removal of the thyroid
  • The presence of anti-thyroglobulin autoantibodies, which are present in up to 30% of thyroid cancer patients, can  cause falsely low serum thyroglobulin concentrations in current immunometric assays
  • Another 0.1% to 3% of patients might have heterophilic antibodies, which can lead to false high thyroglobulin measurements in immunometric assays.
  • Measurement of thyroglobulin by mass spectrometry incorporates trypsin digestion of serum proteins, breaking down anti-thyroglobulin antibodies, heterophilic antibodies, and thyroglobulin into predictable fragments, and enables accurate quantification of thyroglobulin by liquid chromatography-tandem mass spectrometry
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  • Tryptic Protein Fragmentation, Further Purified With Immunocapture, Analysis by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

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  • Day(s) and Time(s) Test Performed: Monday through Friday; 4 p.m.
  • Analytic Time: 2 days
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Kelley Schreiber

Kelley Schreiber is a Marketing Channel Manager at Mayo Medical Laboratories. She is the principle editor and writer of Insights and leads social media and direct marketing strategy. Kelley has worked at Mayo Clinic since 2013. Outside of work, you can find Kelley running, traveling, playing with her new kitten, and exploring new foods.