Test Code TSHC Thyroid Stimulating Hormone (TSH), Ultra Sensitive LAB129
Test Method
Two-Site Immunoenzymatic (“Sandwich”) Assay; Beckman Access II
Performance
Testing is performed Monday through Sunday.
Routine: Typically completed within 4 hours after the
specimen arrives at the testing site.
STAT: Typically completed within 1.5 hours after the
specimen arrives at the testing site.
Useful For
Monitoring patients on thyroid replacement therapy
Confirmation of thyroid-stimulating hormone (TSH) suppression
in
thyroid cancer patients on thyroxine therapy
Prediction of thyrotropin-releasing hormone-stimulated TSH
response
An aid in the diagnosis of primary hyperthyroidism
Differential diagnosis of hypothyroidism
Specimen Requirement
0.5 mL serum or plasma is required.
CPT Code Information
84443 Chemistry: Thyroid Stimulating
Hormone
NCD Frequency Limitations: Testing may be
covered up to two times a year in clinically stable patients;
more
frequent testing may be reasonable and necessary for patients
whose
thyroid therapy has been altered or in whom symptoms or signs
of
hyper or hypothyroidism are noted.
Reference Values
0.3-5.6 mcIU/mL
LOINC Code Information
11580-8 Thyrotropin [Units/Volume] In Serum Or Plasma By
Detection Limit ≤ 0.005 mLU/L
Additional Specimen Collection Information
Collect blood in a lithium heparin, green-top or red-top
tube.
PST and SST (gel tubes) are acceptable. Serum or plasma should
be
separated from contact with the cells within 2 hours of
collection.
Specimens not centrifuged within 4 hours of collection may be
rejected. Refrigerate the specimen if unable to assay within 18
hours of collection. Grossly hemolyzed specimens are not
acceptable. Samples with >3+ lipemia must be cleared prior
to
analysis.