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Test Directory -  Thyroid Receptor Antibodies


TRAb, TSH receptor antibodies

Clinical Indications

Positive TSH receptor antibody (TRAb) identifies the probable cause of Graves' disease. The finding of persistently positive TRAb is useful in indicating that apparent remission of Graves' disease is unlikely to be sustained. TRAb measurement may also be helpful in classification of neonatal thyroid disease and aetiology of atypical eye disease. 

Pregnant women with Graves disease, or that have previously been treated for Graves disease are at risk of having a child with neonatal hypothyroidism. TRAb determination provides a method of assessing the risk of the onset of hyperthyroidism in the foetus.

Request Form 

Combined Pathology Blood form (Yellow/Black or Blue for GP's)


Referral test: Analysed by Immunology, Protein Reference Unit, Sheffield, if specific criteria met.

Specific Criteria

Requested by Consultant Endocrinologist or agreed with Consultant Biochemist. For other requests, TRAb will usually only be undertaken in pregnancy or post-partum or if Thyroid antibodies are not positive (i.e. negative or weak positive).

Patient Preparation


None required

Turnaround Time

3 weeks




0.5 ml


Yellow top (SST) tube

Causes for Rejection

Unlabelled sample, not meeting specific criteria for analysis

Reference Range

Negative 0 - 0.9 IU/L; Equivocal 1.0 - 1.5 IU/L. Positive >1.5 IU/L.

Reference: Sheffield Protein Reference Unit



Please note: this assay does not differentiate between blocking and stimulating antibodies

Lab. Handling

Processing: Aliquot (MPA) and store at 4C in separating fridge (CB39), referral rack.
:  TRAB and send or NOTRB and track at -20C in separating freezer (CB40)

Version 1.0 / August 2014                                                                                                       Approved by: Consultant Biochemist