Test Name: Free T3, Blood
Specimen Type: Serum
Specimen Required: 3-5 Cc Yellow Top Gel Vial
Day Performed: Daily
Reporting Time: 8-24 Hours
Methodology: Beckman Coulter Access II/ Snibe Maglumi 4000
CLINICAL SIGNIFICANCE:
Elevated free T3 (triiodothyronine) values are associated with thyrotoxicosis or excess thyroid hormone replacement. This test is helpful in assessing clinically euthyroid patients who have an altered distribution of binding proteins. It also aids in monitoring the thyroid hormone replacement therapy.
References:
- Salvatore D, Cohen R, Kopp PA, Larsen PR. Thyroid pathophysiology and diagnostic evaluation. In: Melmed S, Auchus RJ, Golfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020: chap 11.
- Weiss RE, Refetoff S. Thyroid function testing. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016: chap 78.