Thyroid Stimulating Immunoglobulin

Overview

  • EPIC Code:
  • LAB746
  • Soft Test Code:
  • TSHIM
  • Send Out Test Code:
  • 30551
Alternate Names
  • TSI
Clinical Significance

Graves' disease is a classic form of hyperthyroid disease, affecting approximately 0.4% of the population in the United States. It is caused by IgG immunoglobulins, collectively known as thyroid stimulating immunoglobulins (TSI). Patients who are candidates for antithyroid drug therapy may not respond to this treatment when TSI levels are markedly elevated. The determination of TSI can also assist in predicting hyperthyroidism in neonates, due to placental transmission of the immunoglobulins from a mother with hyperthyroidism.


Specimen Collection & Preparation

Specimen Requirements

1.0 mL Serum in a SST Gold Top Tube


Transport And Storage

21 days Refrigerated (preferred/transport)
60 days Frozen


Collection Instructions

 


Minimum Volume


Neonatal Volume

Clinical Interpretation

Reference Range:

< 140% Baseline


Test Comments:

Please note: A serum TSH level >350 micro-International Units/mL can interfere with the TSI bioassay, and potentially give higher TSI results.


Methodology:
  • In Vitro Bioassay
Clinical Significance

Graves' disease is a classic form of hyperthyroid disease, affecting approximately 0.4% of the population in the United States. It is caused by IgG immunoglobulins, collectively known as thyroid stimulating immunoglobulins (TSI). Patients who are candidates for antithyroid drug therapy may not respond to this treatment when TSI levels are markedly elevated. The determination of TSI can also assist in predicting hyperthyroidism in neonates, due to placental transmission of the immunoglobulins from a mother with hyperthyroidism.


Production Schedule

Sites Performed
  • Quest - Chantilly
Days Performed
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Departments
  • Sendouts - Clinical
Turn Around Time

5 to 8 days


Coding & Compliance

CDM

01424055


CPT Coding

84445