Thyroglobulin, Serum or Plasma with Reflex to LC-MS/MS or CIA
Also known as: THYROGRFX
Use
The test is recommended for the surveillance of residual or recurrent thyroid cancer. It accurately measures thyroglobulin levels in serum or plasma, serving as a vital component in monitoring thyroid cancer treatment efficacy. Specimens that test negative for thyroglobulin antibodies are tested for thyroglobulin via chemiluminescent immunoassay, while specimens with positive antibody results are tested by LC-MS/MS. It is imperative that clinicians understand results cannot be interpreted interchangeably between methods and should not solely be used to discern papillary or follicular thyroid cancer presence.
Special Instructions
The reflex testing method, whether CIA or LC-MS/MS, is determined based on the TgAb results. It is essential to utilize the recommended serum separator tube (SST) for collection, but green (sodium or lithium heparin) tubes are acceptable. Additional handling charges may apply depending on the testing method conducted.
Limitations
Results from different test methods or kits cannot be used interchangeably. Thyroglobulin results should not be interpreted as absolute evidence of the presence or absence of papillary or follicular thyroid cancer. The test is not recommended as a screening procedure to detect thyroid cancer in the general population. Additionally, the test's lower detection limit for thyroglobulin by LC-MS/MS is 0.5 ng/mL, below which detection capability diminishes. Identification of grossly lipemic samples or the use of EDTA/K2EDTA plasma will result in rejection of the specimen.
New York Approved
Methodology
Immunoassay (CLIA)
Biomarkers
LOINC Codes
- 3013-0
- 8098-6
- 8098-6
- 3013-0
Result Turnaround Time
1-7 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
3 mL
Minimum Volume
1.5 mL
Container
ARUP standard transport tube
Collection Instructions
Collect using a serum separator tube (SST). Transfer to the transport tube post-collection.
Causes for Rejection
EDTA or K2EDTA plasma, grossly lipemic samples, inappropriate fluids other than noted.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 8 hours |
| Refrigerated | 1 week |
| Frozen | 6 months |