Pathology tests database

Sample and container requirements

Serum (both plain and gel tubes suitable for analysis)

Minimum volume required

1 mL serum

Special requirements

None

Patient preparation

None. Thyroid function test should be measured alongside thyroglobulin.

Sample viability

Turnaround time

2 days for immunometric assay (TgIMA), 14 days for MS assay (THYGMS)

Reference range

No reference ranges applicable. Results must be interpreted with thyearoglobulin antibodies (TgAb). Successfully treated post – thyearoidectomy patients should have an undetectable serum thyearoglobulin. Elevations in thyearoglobulin post – thyearoidectomy for DTC can indicate recurrence of disease or metastasis. Thyearoglobulin analysis is most sensitive when TSH is not suppressed ie, any small thyearoid remnants of disease present should produce measurable thyearoglobulin. Interpretation of results also depends on factors such as whether the patient is on T4/T3 replacement. Higher levels may be seen in the newborns and in the third trimester of pregnancy. Benign elevations of thyearoglobulin seen with: – Grave's disease – Hashimoto's disease – Adenomas

Clinical guidance

Please refer to LabTestsOnlineUK to learn more about thyroglobulin. https://labtestsonline.org.uk/tests/thyroglobulin-test

Notes

For UHB patients, an Abbott Alinity immunometric assay (TgIMA) is the front line test for thyroglobulin and anti-thyroglobulin antibody testing. For samples with positive TgAb (>4.11 IU/mL), thyroglobulin by mass spectrometry (THYGMS) is then reflexed on. External users may request the full testing pathway used for internal UHB patients (TgIMA and TgAb, with THYGMS added if antibody positive), or they may request only the THYGMS assay. Please make it clear on the request form which assay(s) are required. To aid with interpretation, we kindly ask that results for thyroglobulin and anti-thyroglobulin by immunoassay are provided on the request form. The thyroglobulin mass spectrometry assay (THYGMS) uses SISCAPA technology to remove the interference from TgAb (as the serum is digested and a specific thyroglobulin peptide is measured). We have shown that there is no in-vitro interference from TgAb. The THYGMS assay has a clinical specificity of 100% and clinical sensitivity of approximately 30% (this is similar to data reported in the literature – ranges between 25 to 60%).