Thyroid
TSH Receptor Antibodies (TRAb)
Thyroid
Stimulating antibodies causing hyperthyroidism. Diagnostic for Graves' disease.
VAT-exempt medical service
TSH receptor antibodies (also called thyrotropin receptor antibodies or TRak) are autoantibodies that bind to the TSH receptor on thyroid cells. Unlike TSH, which stimulates the thyroid in a regulated manner, these antibodies can cause uncontrolled thyroid hormone production, leading to hyperthyroidism. The TRak test is the gold standard for confirming Graves' disease, the most common autoimmune cause of an overactive thyroid.
TRak testing is indicated when hyperthyroidism is suspected or confirmed and the underlying cause needs to be identified. It is also useful for monitoring antibody levels in patients with known Graves' disease, during pregnancy (elevated TRak can cross the placenta and affect the foetus), and when there is a family history of hyperthyroidism with suggestive symptoms. It forms an important component of a comprehensive thyroid antibody panel.
What a high value can mean
A positive TRak result indicates the presence of TSH receptor antibodies, strongly suggesting Graves' disease. In this condition, the antibodies stimulate the thyroid to overproduce hormones, leading to elevated T3 and T4 and suppressed TSH. Symptoms include unintended weight loss, rapid heartbeat, tremors, anxiety, heat intolerance, and an enlarged thyroid (goitre).
What a low value can mean
A negative TRak result means TSH receptor antibodies were not detected. This makes Graves' disease unlikely as the cause of thyroid dysfunction, though some patients with autoimmune thyroid disease may not have detectable antibodies at the time of testing. Retesting may be appropriate if clinical suspicion remains high.
No advance preparation is required. Do not take thyroid medication until after the blood draw. Test before 10 am for optimal results. Avoid vigorous exercise beforehand. Bring valid identification. If you take a supplement containing biotin (often sold for hair and nails), pause it for two days before the test, as high doses can distort the result.
Order your test
Choose your test and pay online. Your lab referral is created straight away.
Give your sample
Visit any of our partner sampling locations. No appointment needed at most of them.
The lab analyses it
Your sample is analysed at an accredited Swedish laboratory.
Get your results
Your values appear in your account with reference ranges and an explanation of each marker.
TRak targets the TSH receptor and is associated primarily with Graves' disease (hyperthyroidism), while TPO antibodies target thyroid peroxidase and are most commonly associated with Hashimoto's thyroiditis (hypothyroidism). Testing both provides a complete autoimmune thyroid picture.
Yes. TSH receptor antibodies can cross the placenta and stimulate the foetal thyroid, potentially causing neonatal hyperthyroidism. Monitoring TRak levels during pregnancy is important for women with Graves' disease.
Higher TRak levels tend to correlate with more active disease. Tracking antibody levels over time helps assess treatment response and the likelihood of remission after anti-thyroid therapy.