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Microbiology & Infection
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Currently under review
Pending specialist review and validation.
The thyroglobulin antibody test measures autoantibodies your immune system may produce against thyroglobulin, a protein made by the thyroid gland. These antibodies are found in the blood and can reflect immune activity directed at thyroid tissue.
Clinicians use this test to help evaluate autoimmune thyroid conditions and to interpret thyroglobulin tumor marker testing in people who have been treated for thyroid cancer. The presence of these antibodies can interfere with some thyroglobulin measurements, so knowing your antibody status helps make other thyroid tests more reliable.
If you have symptoms of thyroid dysfunction, a family history of thyroid disease, or other autoimmune conditions, your clinician may order this test along with thyroid hormone and thyroid peroxidase antibody tests. It helps detect autoimmune thyroiditis and can support the diagnosis in the right clinical context.
For those monitored after treatment for differentiated thyroid cancer, thyroglobulin antibody status is important because it can affect how thyroglobulin results are interpreted. Tracking whether antibody levels are present or changing over time can offer clues about thyroid tissue activity and guide follow-up plans.
A result reported as negative or very low suggests that your immune system is not making a measurable amount of thyroglobulin antibodies. A positive result indicates the presence of autoantibodies and is common in autoimmune thyroid disease. On its own, a positive result does not diagnose a specific condition and does not necessarily mean cancer.
Your clinician will interpret this result alongside your symptoms, exam findings, thyroid hormone tests, and sometimes imaging. For people followed after thyroid cancer treatment, the trend of antibody results over time can be informative. Because different laboratories use different methods, it is best to use the same lab for repeat testing whenever possible. If results are unexpected, your clinician may repeat the test or use additional methods to clarify the picture.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
Biotin can interfere with some immunoassay methods and may skew thyroglobulin antibody results. Tell your clinician about any biotin-containing supplements and follow instructions about holding them before blood draw.
After thyroid surgery or radioiodine therapy, thyroglobulin antibody levels can change over time. Your care team may focus on trends rather than a single value to understand what is happening.
Hashimoto thyroiditis and Graves disease are frequently associated with thyroglobulin antibodies. Their presence supports, but does not by itself prove, an autoimmune cause of thyroid dysfunction.
Steroids, rituximab, and other immunosuppressants can reduce antibody production and may lower measured thyroglobulin antibody levels. Always share your current medication list with the lab and your clinician.
Immune changes during pregnancy and after delivery can alter autoimmune antibody levels. Your clinician will interpret results with these physiologic changes in mind.
Different laboratories use different methods and calibration standards. Results from different labs are not always interchangeable, so try to use the same lab for serial testing.
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