Thyroid Stimulating Immunoglobulin
0099430
 
Ordering Recommendation
Not routinely ordered. Preferred testing for autoimmune thyroid disease.
Mnemonic
TSI
Methodology
Quantitative Bioassay/Quantitative Chemiluminescent Immunoassay
Performed
Mon-Sat
Reported
2-5 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Plain red or serum separator tube.  
Specimen Preparation
Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.7 mL)  
Storage/Transport Temperature
Frozen.  
Unacceptable Conditions
Plasma.  
Remarks
 
Stability
After separation from cells: Ambient: 2 hours; Refrigerated: 6 days; Frozen: 3 months  
Reference Interval
Effective August 20, 2012
Negative 122% basal activity or less
Positive 123% basal activity or greater
Interpretive Data
Positive results (123 percent or greater) are consistent with Graves disease but do not always correlate with the presence and severity of hyperthyroidism. Antibodies to the Thyroid Stimulating Hormone Receptor (TSHR) may be stimulating, blocking, or neutral. Stimulating antibodies mimic the action of TSH and cause hyperthyroidism (Graves disease). This test determines the net effect of all TSHR antibody types present in the serum specimen.

See Compliance Statement B: www.aruplab.com/CS
Note
An elevated Thyroid Stimulating Hormone (TSH) value above 6 mU/L may produce a weakly positive Thyroid Stimulating Immunoglobulin (TSI) result (123 percent or greater).
CPT Code(s)
84445
Components
Component Test Code*Component Chart Name
0099430Thyroid Stimulating Immunoglobulin
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, contact interface support at interface.support@aruplab.com.
Cross References
  • Autoimmune Thyroid Stimulator
  • Thyroid Stimulating Antibody
  • Thyroid-Stimulating Immunoglobulin Serum
  • TSI
  • TSI concentration