Days Set Up
Monday, Thursday
Analytic Time

2 - 7 days

MiChart Code
Thyroid Stimulating Immunoglobulin
Soft Order Code
TSI

Test Updated:

Synonyms

LATS
LATS (Long Acting Thyroid Stimulator)
Long Acting Thyroid Stimulator (LATS)
TSI
TSIS
THYROID STIMULATION IG

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Test Overview

Test Methodology

Chemiluminescent Immunoassay

Test Usage

Diagnosis of hyperthyroidism; diagnosis of patients with normal routine thyroid tests but in whom progessive exophthalemia and/or Grave's disease is still suspected.

Reference Range

<0.55 IU/L
Thyroid Stimulating Immunoglobulin is measured by the Siemens Immulite 2000 Chemiluminescent Immunoassay method. The cutoff value of 0.55 IU/L was determined from a ROC curve analysis and has consistently shown a sensitivity of >98% and specificity of >99% for the diagnosis of Graves’ Disease.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Onsite

Collect blood in an SST tube.

Collection Offsite

Collect blood in an SST tube. Centrifuge, aliquot serum into plastic vial and refrigerate up to 7 days or freeze for longer storage.

Red Top Tube
Normal Volume
0.5 mL serum
Minimum Volume
0.3 mL serum

Billing Information

CPT Code
84445
Pro Fee Code
 
LOINC
30567-2

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.