TSH receptor antibody (TRAK) is a thyroid autoantibody that may be present in the blood, particularly in Graves’ type hyperthyroidism. Graves’ disease is an autoimmune disease of the thyroid gland that is often associated with goiter (enlargement of the thyroid gland), hyperthyroidism (hyperthyroidism), and endocrine orbitopathy (involvement of the eyes).
The antibody is directed against the TSH receptor located on thyroid cells. When TRAK binds with the receptor, there is prolonged stimulation of the thyroid cells (hyperthyroidism/hyperthyroidism).
Note: TRAK antibodies belong to the class of IgG antibodies and have a transplacental (“across the placenta“) effect, i.e., they can lead to neonatal thyroid disease (“affecting the newborn”).
The procedure
Material needed
- Blood serum
Preparation of the patient
- Not necessary
Disruptive factors
- None known
Standard values
| Normal value in % | < 9 |
| Clearly positive | > 14 |
Indications
- Suspected thyroid dysfunction.
- Alopecia (hair loss)
- Habitual abortion – ≥ three miscarriages of unclear cause.
- Addison’s disease (primary adrenocortical insufficiency/underfunction of adrenal cortex) [Graves’ disease may occur together with Addison’s disease due to common autoimmune process].
- TRAK determinations in the last trimester of pregnancy (in patients with a history of thyroid disease).
Interpretation
Interpretation of increased values
- Graves’ disease (see above for definition) [detection frequency: 80-100%].
- Postpartum thyroiditis – special form of chronic thyroiditis that occurs after childbirth. In this case, a temporary hyperthyroidism (hyperthyroidism) develops, which is followed by a temporary hypothyroidism with spontaneous healing. [Detection frequency: 50-70%]
- Hashimoto’s thyroiditis (thyroiditis Hashimoto; autoimmune thyroiditis) – autoimmune disease of the thyroid gland, which leads to hypothyroidism (hypothyroidism) [detection frequency: circa 10%].
- Primary myxedema (atrophic autoimmune thyroiditis) [detection frequency: 0-5%]
- Thyroid autonomy (rare) [detection frequency: circa 5%]
- Healthy [detection frequency: 0%]
