Thyroglobulin Mass Spectrometry, Serum
Use
The test is crucial for accurately measuring serum thyroglobulin (Tg) levels in patients with antithyroglobulin autoantibodies (TgAb) or heterophile antibodies (HAb). It aids in diagnosing early phase silent thyroiditis versus Graves disease in non-thyroid cancer patients, and serves as a reflex test for unknown TgAb statuses showing positive during immunoassay testing. Given its specific detection through LC-MS/MS, it overcomes interferences from TgAb or HAb, providing reliable results, crucial for assessing thyroid cancer recurrence risk post-thyroidectomy.
Special Instructions
Not provided.
Limitations
The measurement can be affected by the presence of TgAb or HAb, especially impacting immunoassay methods. Mass spectrometry offers a reliable alternative but assessing test results requires cautious comparison, especially with differing TSH levels. Variations in amino acid sequences within Tg may lead to a false-low result, impacting a small fraction of measurements. Elevated results in patients without thyroid cancer may be due to non-cancerous thyroid conditions like goiter or Graves disease, especially when including substantial thyroid remnants.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
Thyroglobulin
Protein
LOINC Codes
- 3013-0 - Thyroglob SerPl-mCnc
- 3013-0 - Thyroglob SerPl-mCnc
- 59462-2 - Clinical biochemist review
Result Turnaround Time
3-10 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1.25 mL
Minimum Volume
0.75 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial. Red top is required, as serum gel/SST tubes are not acceptable.
Causes for Rejection
Reject if gross lipemia; OK for gross hemolysis and icterus.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 7 days |
| Frozen | 416 days |