TSH Receptor Antibodies (TRAb)
Chemical Pathology
Notes
- TSH receptor antibodies (TRAb) are antibodies directed against the TSH receptor and may be stimulatory or inhibitory.
- TRAb levels are measured to differentiate between thyrotoxicosis with hyperthyroidism (for example, Graves' disease or toxic nodular disease) and thyrotoxicosis without hyperthyroidism (for example, transient thyroiditis).
- Measurement is also indicated in pregnant patients with a past or current history of active Graves disease, to determine the risk of neonatal thyrotoxicosis.
- The primary test for the investigation of autoimmune hypothyroidism is the detection of anti -Thyroid Peroxidase (TPO) antibodies.
Sample requirements
5 ml of blood taken into a narrow plain gold top gel tube.
Storage/transport
Send samples at ambient temperature to the laboratory on the day of collection. If unavoidable samples may be refrigerated overnight.
Required information
Relevant clinical details including reason for the request.
Turnaround times
Samples are sent for analysis to St Thomas' Hospital, with results expected back within 2 weeks.
Reference ranges
Results < 3.10 IU/L: Negative
Results ≥ 3.10 IU/L: Positive
Further information
Page updated 30/06/2023