Lab Test

TSH Receptor Antibody (TRAb)

Thyrotropin Receptor Ab, TSH-Binding Inhibiting Immunoglobulin

Test Codes

Mayo: THYRO, EPIC: LAB6172, Beaker: XTRAB

Department

Send Outs

Instructions

Patient Preparation: For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One plain Red-top tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.8 mL)

Rejection Criteria

  • Grossly hemolyzed specimens.
  • Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.8 mL) 

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): unacceptable
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 1 month

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Mayo Clinic Laboratories in Rochester, MN.

Performed

Monday – Saturday.
Results available in 2-4 days.

Reference Range

By report.

Test Methodology

Quantitative Electrochemiluminescent Immunoassay.

Interpretation

  • TSH Receptor Antibodies are measured in this assay by the thyrotropin binding inhibiting immunoglobulin technique (TBII). Results are reported as percent inhibition of TSH binding.
  • Positive results are consistent with autoimmune thyroid disease.

Clinical Utility

The TSH receptor antibody (TRAb) assay aids in the differential diagnosis of Graves' disease (positive in > 85%) versus toxic nodular goiter. TRAb levels aid the clinician in prescribing the most appropriate course of therapy upon initial diagnosis. This assay is also used to monitor the efficacy of anti-thyroid drug therapy to predict the likelihood of disease remission.

CPT Codes

83520
LOINC:  5385-0

Contacts

Last Updated

7/15/2021

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