Test Overview
Test Methodology

Electrochemiluminescence Immunoassay (ECLIA)

Test Usage

Used in diagnosis of hyperthyroidism and Graves' disease.

Reference Range *

< or = 1.75 IU/L. At a decision limit of 1.75 IU/L, this assay has 97% sensitivity and 99% specificity for detection of Graves' disease. In healthy individuals and in patients with thyroid disease without diagnosis of Graves' disease, the upper limit of anti-TSHR values are 1.22 IU/L and 1.58 IU/L, respectively (97.5th percentiles).

Test Details
Days Set Up
Monday - Friday
Analytic Time

1 - 4 days

Soft Order Code
THYRO
MiChart Code
Thyrotropin Receptor Antibody
Synonyms
  • Thyrotropin Binding Inhibitory Immunoglobulin
  • Thyroid Stimulating Immunoglobulin
  • Thyroid Stimulating Hormone Receptor Antibody
  • TSH Binding Inhibition Index
  • Thyrotropin-Binding Inhibition Index
  • TSH Receptor Antibody
  • THYROTR
  • Thyrotropin Receptor Ab
Laboratory
Sendout
Reference Laboratory
Mayo THYRO (81797)
Section
Special Testing
Specimen Requirements
Collection Instructions

Collect specimen in a red top or SST tube. Centrifuge, aliquot serum into a plastic vial and refrigerate. This test should not be requested in patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference.

Yellow Top Tube
Normal Volume
1 mL serum
Minimum Volume
0.8 mL serum
Additional Information

Measures both Thyroid Stimulating Immunoglobulin (TSI) and Thyrotropin Binding Inhibitory Immunoglobulin (TBII), but does not provide information about function. The Thyrotropin Receptor Autoantibody (TRAB) Assay has utility in the differential diagnosis of Graves disease versus toxic nodular goiter. A low-positive TRAB (15-60) upon initial diagnosis is indicative of a high likelihood that a 6-18 month course of anti-thyroid drug medication will result in remission of Graves disease. Conversely, a high-positive TRAB (>80) upon initial diagnosis indicates a low likelihood of disease remission following anti-thyroid therapy. Studies show that 83% of patients with detectable receptor antibody activity (i.e., an elevated TRAB) at the end of a twelve month course of anti-thyroid drug therapy subsequently relapse. Non-elevated TRAB concentrations after twelve months of drug treatment predict remission in 89% of patients at 1 year and in 81% at 3 years after drug withdrawal. In the most current studies, the frequency of an elevated TRAB in patients with confirmed Graves disease ranges from 94-100%. Test sent to Mayo Medical Laboratories.

Billing
CPT Code
83520
Fee Code
AA236
LOINC
5385-0
NY State Approved
No