Reference Range
No reference ranges applicable. Results must be interpreted with Tg antibodies. Tg analysis is most sensitive when TSH is not suppressed (>30 mIU/L) i.e. any small thyroid remnants of disease present should produce measurable Tg
Elevations in Tg post-thyroidectomy for differentiated thyroid cancer can indicate recurrence of disease or metastasis
Interpretation of results also depends on factors such as whether the patient is on T4/T3 replacement.
The limit of detection of the assay is < 5 ug/L.
Higher levels may be seen in the newborn and in the third trimester of pregnancy.
Benign elevations:
- Grave's
- Hashimoto's
- Adenoma
References
British Thyroid Association & Royal College of Physicians, Thyroid Cancer Guidelines 2007
Spencer et al., 2005. Clinical Impact of Tg and TgAb Method Differences on the Management of Patients with Differentiated Thyroid Carcinomas. J Clin Endocrinol Metab 90:5566-5575