Thyroid Cascade Profile

Additional Information:

UFHPL Epic order code: LAB2107422


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CPT Code(s):

If reflex testing is performed, additional CPT codes (e.g., 84439, 84481, 86376) and concomitant charges may apply.

Specimen Requirements:

Important: Special reflexing. If TSH is < 0.450, it will reflex to thyroxine (T4), free, direct and depending on the thyroxine (T4), free, direct result, may reflex to a triiodothyronine (T3), free, both at an additional charge. If the TSH is > 4.500, it will reflex to thyroxine (T4), free, direct and depending on the thyroxine (T4), free, direct result, may reflex to a thyroid peroxidase (TPO) antibody, both at an additional charge.

Type: Serum

Container/Tube: Red-top tube or gel-barrier tube

Sample Volume: 2 mL

Minimum Volume: 1 mL (Repeat testing is not possible with this specimen volume.)

  • If a red-top tube is used, transfer the separated serum to a plastic transport tube.

Storage: Refrigerate specimens immediately after collection.

Stability (collection to time of analysis/testing):

  • Ambient: 14 days
  • Refrigerated: 14 days
  • Frozen: 14 days
  • Freeze/Thaw Cycles: Stable (x 3)
Rejection Criteria:

  • Plasma specimen


This test is used to aid clinicians in obtaining an appropriate diagnosis for common adult thyroid disorders. The cascade begins with a third-generation thyroid-stimulating hormone (TSH) test. If the TSH result is normal, a euthyroid status is assumed and testing stops. Additional testing is performed only if the initial TSH result is abnormally high or low. The cascade algorithm will select specific tests, based on the results of previously performed tests, which are necessary to arrive at the most appropriate laboratory diagnosis. The assayed value of a test, relative to the reference interval of that specific test, determines which, if any, additional tests are performed. The cascade proceeds, selecting specific tests, until the most probable diagnosis can be made.
This test includes thyroid-stimulating hormone (TSH) with automatic reflex (as diagnosticall
my warranted) to free thyroxine, free triiodothyronine, and/or thyroid peroxidase (TPO) antibodies. If reflex testing is performed, additional charges/CPT code(s) may apply.


This profile is not intended for use in pediatric patients or in monitoring patients receiving treatment for thyroid disease with either ablative or suppressive therapy. It would also not be appropriate to use this procedure to diagnose primary thyroid neoplasm.


Electrochemiluminescence immunoassay (ECLIA)