Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
TRAbs are antibodies directed against the thyroid TSH receptor.
The clinical uses of its measurement are as follows:-
Diagnosis and monitoring of Graves Disease: Graves disease is caused by the presence of TRAbs, which stimulate the TSH receptor leading to hyperthyroidism. Measurement of TRAbs is therefore useful in the differential diagnosis of hyperthyroidism. Monitoring TRAbs in patients with known Graves disease can also predict short-term relapses following a course of anti-thyroid drugs.
Prediction of the risk of thyrotoxicosis in the foetus or neonate: TRAbs may cross the placenta and potentially cause fetal and neonatal hyperthyroidism (or hypothyroidism in the case of blocking antibodies), which carries increased risk of neonatal morbidity and mortality if not recognised and treated.
Specimen container paediatric:
Serum-SST
Specimen container adult:
Serum-SST
Minimum volume paediatric:
1 mL blood
Minimum volume adult:
2 mL blood
Special requirements:
None noted
Sample stability:
Unseparated:
Same day
Separated:
3 days at 4 to 8oC,
1 month at -20oC
Transport requirements:
Ambient
Interpretation:
TRAB >1.8 IU/L is regarded as positive
TRAB 1.0 to 1.8 IU/L is equivocal
TRAB <1.0 IU/L is regarded as negative
Reference ranges:
Results of greater than 1.8 U/L are considered positive.
Factors affecting result:
Gross haemolysis, lipaemia or icterus may interfere.