Test Description

Reverse triiodothyronine (RT3) differs from triiodothyronine (T3) in the positions of the iodine atoms attached to the aromatic rings. The majority of RT3 found in the circulation is formed by peripheral deiodination (removal of an iodine atom) of T4 (thyroxine). RT3 is believed to be metabolically inactive. The Reverse T3 Test helps evaluate thyroid function and metabolism.

When should this test be ordered?
This test could be ordered as an aid in the diagnosis of the "sick euthyroid" syndrome or any thyroid related disorders.
High Risk · <=11.5 & >=29.8 (ng/dL)
Out of Reference Range.
Borderline Risk · None
Not determined for this test.
Low Risk · 11.6 - 29.7 (ng/dL)
Within Reference Range.
Testing Method Used
Mass Spec.

Please ship samples daily.
Improvements and Prevention
Please consult your physician.
Specimen Type
Serum
Fasting Required
No, but may be done with other tests that requires fasting.
Drawing and Processing
  1. Draw from a vein into a SST tubetube1
  2. Invert tube (do not shake) 1-2 times to mix adequately
  3. Let stand upright in tube rack for 30 minutes
  4. Centrifuge for 15 minutes at 3300rpm
  5. Do not leave at room temperature for more than 1 hour
  6. Keep cold in a refrigerator to maintain stability, until ready to ship
Shipping Instructions
  1. Freeze ice packs 24 hours prior to use
  2. Place ice packs inside the Styrofoam insulated kit
  3. Place processed tubes inside biohazard bag, place inside kit
  4. Seal box, print airbill and adhere to box and wait for courier to pick up
Rejection Criteria
QNS; temperature out of range upon receipt; grossly hemolyzed or lipemic; wrong specimen type; sample stability exceeded for this analyte; unlabeled or mislabeled specimen.
References

The information provided here is intended for educational purposes only and should not be used or substituted as medical advice. You should consult a healthcare practitioner regarding medical diagnosis or treatment.