Result Test Name
T3 ANTIBODY
Laboratory
QUEST LAB
Result Test Code
12385990460
Laboratory Test Name
QUEST T3?(TRIIODOTHYRONINE) ANTIBODY
Reportable Test Name
-
Result LOINC
43172-6
Collection Container
SST
Units
-
Collection Requirements
Preferred Specimen(s) 1 mL serum Minimum Volume 0.5 mL
Container Temp
Room Temperature (1)
Container Volume
.500
Test Info
T3 (Triiodothyronine) Antibody - This test helps identify triiodothyronine (T3) thyroid hormone autoantibodies (THAAbs) which may interfere with T3 immunoassays in individuals with discordant serum T3 levels [1]. THAAbs may present in healthy individuals but are more common in patients with autoimmune thyroid diseases. THAAbs may affect both 1-step and 2-step immunoassays; the interference may be transient or persist for years. T3 THAAbs interfere with T3 measurements by competing with T3 antibodies used in the T3 immunoassays. When the serum T3 level is discordant with clinical manifestations or other test results (eg elevated T3 levels with normal or elevated thyroid stimulating hormone [TSH] levels) this test may be used to determine whether T3 THAAbs are the cause of discordance [1]. Other methods of screening for interference by T3 THAAbs are polyethylene glycol precipitation and comparison against equilibrium dialysis. Anomalous T3 levels may also be caused by a range of interfering substances such as biotin heterophilic antibodies and antibodies to streptavidin and ruthenium [1]. Other conditions that may result in elevated free thyroxine and/or free T3 levels without suppressed TSH levels include thyroxine replacement therapy familial dysalbuminemic hyperthyroxinemia certain drugs (eg amiodarone and heparin) nonthyroidal illness neonatal period TSH-secreting pituitary adenoma resistance to thyroid hormone and disorders of thyroid hormone transport or metabolism [2]. The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings. References 1. Favresse J et al. Endocr Rev. 2018;39(5):830-850. 2. Gurnell M et al. Clin Endocrinol (Oxf). 2011;74(6):673-678.
Shipping Instructions
Transport Container Transport tube Transport Temperature Room temperature Specimen Stability Room temperature: 14 days Refrigerated: 14 days Frozen: 28 days Reject Criteria Gross hemolysis Grossly lipemic Plasma