TSI (Thyroid Stimulating Immunoglobulin) (THYSI)

Test Code
LAB746

Quest Code
30551

CPT Codes
84445

Preferred Specimen
1 mL serum collected in plain red top tube

Minimum Volume
0.2 mL

Transport Container
Transport tube

Transport Temperature
Refrigerated (cold packs)

Specimen Stability
Room temperature: Unacceptable
Refrigerated: 21 days
Frozen: 60 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemic • Received room temperature • Grossly icteric

Methodology
In Vitro Bioassay

Setup Schedule
Tuesday-friday

Reference Range

<140% Baseline



Clinical Significance
Graves' disease is a classic form of hyperthyroid disease, affecting approximately 0.4% of the population of 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.

Performing Laboratory
Quest Diagnostics Nichols Institute-Chantilly VA
14225 Newbrook Drive
Chantilly, VA 20151-2228




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.