TG testing (Thyroglobulin)

What is thyroglobulin?

Thyroglobulin (TG) is a protein produced exclusively by follicular thyroid cells, both normal and cancerous. Testing its concentration is useful in observing the development of thyroid cancerous lesions.

TG testing

Thyroglobulin is involved in the synthesis, storage and release of the thyroid hormones: thyroxine (T4) and triiodothyronine (T3). The production of these hormones and their release into the bloodstream is stimulated by the pituitary hormone - thyrotropin or thyroid-stimulating hormone (TSH).

In a healthy person, no or very little TG enters the bloodstream. The exception is when the thyroid structure (follicular cells) is destroyed by inflammatory or neoplastic lesions.

Therefore, this protein is a useful tumour marker, especially for differentiated thyroid cancer.

What does the thyroglobulin test determine?

The test determines the concentration of thyroglobulin in the blood and is often used:

• for evaluating the effectiveness of thyroid cancer treatment,

• for detecting the recurrence of certain types of thyroid cancer,

• in the diagnosis of congenital hypothyroidism in infants,

• in patients with symptoms of thyroid inflammation.

Testing of thyroglobulin levels should be done in conjunction with testing of thyroid hormones (fT3, fT4) and pituitary hormone (TSH) before starting treatment.

TG test: preparation and results

Determination of TG levels is performed from a blood sample. The material for the test is usually taken from the patient's cubital vein. This is done following the sample collection procedure - skin disinfection, application of a tourniquet, and pressure on the injection site.

The TG test does not require any special preparation. It is advisable to carry out the test by 11:00 on an empty stomach.

Medications containing thyroid hormone can affect the test results.

There are no contraindications to performing the test.

The product can be used within 3 months from the date indicated in the order confirmation.