T4 (Thyroxine) Antibody
Test Code
36576
83519
In-home collection is not available in your area through Quest Mobile.
Clinical Significance
T4 (Thyroxine) Antibody - This test helps identify thyroxine (T4) thyroid hormone autoantibodies (THAAbs), which may interfere with T4 immunoassays in individuals with discordant serum T4 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. T4 THAAbs interfere with T4 measurements by competing with T4 antibodies used in the T4 immunoassays. When the serum T4 level is discordant with clinical manifestations or other test results (for example, ...
Test Resources
Clinical Focus
Thyroid Dysfunction in Nonpregnant AdultsTest Details
Methodology
Radiobinding Assay (RBA)
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Reference Range(s)
Negative
Preferred Specimen(s)
1 mL serum
Minimum Volume
0.5 mL
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
Setup Schedule
1 mL serum
0.5 mL
Transport tube
Room temperature
Room temperature: 14 days
Refrigerated: 14 days
Frozen: 28 days
Refrigerated: 14 days
Frozen: 28 days
Gross hemolysis • Grossly lipemic • Plasma