Laboratory Services

Thyrotropin Receptor Antibody, Serum

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Updated Test Information:

Test Description
Thyrotropin Receptor Antibody, Serum
Synonym(s)

Antibodies to TSH receptor; Inhibitory Immunoglobulin; Long-Acting Thyroid Stimulator (LATS); TBII (TSH-Binding Inhibiting Immunoglobulin); Thyroid-Stimulating Hormone Receptor (TSH Receptor) Antibody; TRAb (Thyrotropin Receptor Antibody); TSH (Thyroid-Stimulating Hormone) Receptor Binding; TSH Binding Inhibition Index; TSH Receptor (Thyroid-Stimulating Hormone Receptor) Antibody; TSH-Binding Inhibiting Immunoglobulin (TBII); Graves Disease

Test ID
THYRO
General Information

Useful for:



  • Recommended first-line test for detection of thyrotropin receptor (TSHR) antibodies, and used in the following
    situations:

    • Differential diagnosis of etiology of thyrotoxicosis in patients with ambiguous clinical findings and/or contraindicated
      (eg, pregnant or breast-feeding) or nondiagnostic thyroid radioisotope scans

    • Diagnosis of clinically suspected Graves disease (eg, extrathyroidal manifestation of Graves disease include endocrine exophthalmos, pretibial myxedema, thyroid acropachy) in patients with normal thyroid function tests

    • Determining the risk of neonatal thyrotoxicosis in a fetus of a pregnant female with active or past active Graves disease

    • Differential diagnosis of gestational thyrotoxicosis versus first trimester manifestation or recurrence of Graves disease

    • Assessing the risk of Graves disease relapse after antithyroid drug treatment



Specimen Type

Serum

Specimen Requirements

  • Preferred: Red Top

  • Acceptable: Serum Gel (SST)

Specimen Collection / Processing 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

    • Patient should not be receiving heparin treatment



Stability

  • Refrigerated (preferred): 7 days

  • Frozen: 30 days

Unacceptable Specimen Conditions

Gross hemolysis

Limitations

In rare cases, interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur

Methodology

Electrochemiluminescence Immunoassay

Estimated TAT

1-3 days

Testing Schedule

Monday-Saturday

Retention

3 months

CPT Code(s)

83520

Additional Information
Minimum Sample Volume

0.5 mL

Reference Range

≤ 1.75 IU/L

Performing Lab

Mayo

LOINC Code(s)

5385-0