Clinical Significance
T3 Uptake (REFL) - Decreased: Pregnancy, estrogens, hyperproteinemia, acute intermittent porphyria.
Increased: Androgens, hyperproteinemia, stress, acute liver disease.
This assay is a measure of available thyroid hormone binding sites and should be interpreted with thyroxine levels.
Preferred Specimen(s)
1 mL serum
Alternative Specimen(s)
Plasma collected in: Sodium heparin (green-top) tube or lithium heparin (green-top) tube
Minimum Volume
0.5 mL
Transport Container
Serum separator tube (SST)
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 7 days
Refrigerated: 10 days
Frozen: 28 days
Includes
This is a client specific reflex test. Reflex criteria has been pre-defined by the ordering physician. Additional testing will be performed at an additional charge.
Methodology
Immunoassay (IA)
Reference Range(s)
22-35 %