Quick Facts
- Sample: Blood draw from arm vein
- Fasting: No fasting required unless directed by your healthcare provider
- Turn-around: 3-5 business days. May take longer based on weather, holiday, or laboratory delays.
Benefits
- Thyroid cancer monitoring - Helps monitor patients previously treated for differentiated thyroid cancer
- Autoimmune thyroid insight - Measures Thyroglobulin Antibodies (TgAb), which may indicate autoimmune thyroid conditions such as Hashimoto’s thyroiditis or Graves’ disease
- Convenient testing access - Order online and visit a local lab without a doctor’s office visit
- Post-treatment surveillance - Assists healthcare providers in evaluating treatment response and monitoring for possible recurrence
- Comprehensive thyroid marker testing - Measures both thyroglobulin (Tg) and thyroglobulin antibodies in a single panel
Important Disclaimer
In patients with high Thyroglobulin Antibodies (TgAb), this test may produce falsely low or undetectable thyroglobulin results due to antibody interference. In these cases, LC/MS-based testing may be more appropriate for thyroid cancer monitoring. Please consult your healthcare provider regarding the most suitable testing method for your condition.
Who Is This Test For?
- Individuals previously treated for differentiated thyroid cancer
- Patients undergoing thyroid cancer follow-up or recurrence monitoring
- People with suspected or diagnosed autoimmune thyroid disease
- Individuals with elevated or abnormal thyroid antibody levels
- Patients experiencing symptoms of thyroid dysfunction, including fatigue, weight changes, hair loss, or neck swelling
- Adults seeking additional thyroid health evaluation as recommended by their healthcare provider
How It Works – Just 3 Steps
- Order online - Select your test and complete checkout online, then choose a convenient lab location.
- Visit the lab - Visit one of thousands of participating labs for a quick blood draw.
- Get results - Receive secure online results within approximately 3-5 business days.
FAQ
What does this test measure? This panel measures Thyroglobulin (Tg) and Thyroglobulin Antibodies (TgAb). Thyroglobulin is a protein produced by thyroid tissue, while TgAb are antibodies that may interfere with Tg measurement and may indicate autoimmune thyroid disease.
What is thyroglobulin used for? Thyroglobulin testing is primarily used to monitor patients after treatment for differentiated thyroid cancer, particularly after thyroid removal or radioactive iodine treatment.
Why are Thyroglobulin Antibodies important? Elevated TgAb levels can interfere with standard thyroglobulin immunoassays and may produce falsely low or undetectable results. This can affect the accuracy of thyroid cancer monitoring.
When is LC/MS thyroglobulin testing recommended? LC/MS-based thyroglobulin testing may be recommended for patients with elevated Thyroglobulin Antibodies (TgAb), since this method is less affected by antibody interference.
Do I need to fast before testing? Fasting is generally not required unless instructed by your healthcare provider.
Can this test diagnose thyroid cancer? No. This test is primarily intended for monitoring and follow-up purposes and should not be used alone to diagnose thyroid cancer.
What happens if my results are abnormal? Abnormal results should be reviewed with your healthcare provider, endocrinologist, or oncologist, who may recommend additional testing or follow-up imaging.
More Details
What is the purpose of this test?
The Thyroglobulin Panel Blood Test measures thyroglobulin (Tg) and Thyroglobulin Antibodies (TgAb) in the blood. Thyroglobulin is a protein produced only by thyroid tissue and is commonly used to monitor patients after treatment for differentiated thyroid cancer.
After thyroidectomy or thyroid cancer treatment, thyroglobulin levels are monitored to help evaluate whether thyroid tissue remains or if cancer recurrence may be present. The panel also measures TgAb levels because these antibodies can interfere with standard thyroglobulin testing methods.
Elevated Thyroglobulin Antibodies are commonly associated with autoimmune thyroid conditions such as Hashimoto’s thyroiditis and Graves’ disease.
Who would benefit from this test?
This test may benefit:
- Patients with a history of differentiated thyroid cancer
- Individuals undergoing post-treatment surveillance
- Patients with autoimmune thyroid disease
- Individuals with abnormal thyroid antibody findings
- Patients being monitored after thyroid surgery or radioactive iodine treatment
How do I interpret the results?
Thyroglobulin (Tg)
Low or undetectable Tg levels after thyroid cancer treatment may suggest successful treatment, though interpretation depends on clinical history and imaging findings.
Elevated Tg levels may indicate remaining thyroid tissue or possible recurrence and should be evaluated by a healthcare provider.
Thyroglobulin Antibodies (TgAb)
Elevated TgAb levels may suggest autoimmune thyroid disease and can interfere with standard Tg testing accuracy.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
No special preparation is typically required for this test unless otherwise instructed by your healthcare provider.
Be sure to inform your provider about:
- Thyroid medications
- Recent thyroid treatments or surgery
- Autoimmune thyroid conditions
- Pregnancy status
- Recent imaging studies or radioactive iodine treatment
How often should I get tested?
Testing frequency depends on your condition and provider recommendations.
Common monitoring schedules may include:
- Every 3-6 months after thyroid cancer treatment
- Annual monitoring for long-term surveillance
- Additional testing after abnormal results or treatment changes
Why does antibody interference matter?
Standard thyroglobulin immunoassays may be affected by elevated TgAb levels. In some cases, this interference may produce falsely low or undetectable thyroglobulin results, potentially limiting the usefulness of the test for cancer surveillance.
Patients with elevated TgAb levels should discuss whether LC/MS-based thyroglobulin testing may be more appropriate for their clinical monitoring needs.
Related tests you may consider
Thyroid Stimulating Hormone (TSH) Test - Evaluates overall thyroid function and treatment response.
Free T3 and Free T4 Panel - Measures active thyroid hormone levels.
Thyroid Peroxidase Antibody (TPOAb) Test - Helps evaluate autoimmune thyroid disease.
