TSI (Thyroid Stimulating Immunoglobulin)

Test Code

TSI

Quest Code

30551

Alias/See Also

30551

CPT Codes
84445

Preferred Specimen

1 mL serum

Minimum Volume

0.2 mL

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 • Grossly icteric • Plasma

Methodology
In Vitro Bioassay

Setup Schedule

Set up: Mon-Sat; Report Available: 2-4 days

Report Available

Maximum Laboratory Turn Around Time 8 days

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
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130

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.