Measurement of thyroglobulin (Tg) is useful in the detection of residual or recurrent thyroid cancer. Many individuals develop auto-antibodies to Tg (Tg Ab) and the presence of Tg Ab interferes with the measurement of immunoassay Tg. It is therefore necessary to identify the presence/absence of Tg Ab before measuring Tg. The panel will first measure Tg Ab; if the patient is Tg Ab negative, Tg will be measured using a Second Generation immunoassay with increased low-level sensitivity to 0.05 ng/mL. If the Tg Ab is positive, Tg will be measured by tandem mass spectroscopy. The LC/MS/MS assay will provide quantitative measurement of Tg in the presence of Tg Ab.
< or = 1 IU/mL
Collect specimen in an SST or red top tube. Centrifuge, aliquot serum into a plastic vial and freeze.Specimen should be drawn at least 8 hours after last biotin administration.
Test includes Thyroglobulin Antibody. If Thyroglobulin Ab result is < or = 1 IU/mL, then Thyroglobulin, Second Generation (Beckman Coulter) will be performed at an additional charge (CPT 84432). If Thyroglobulin Ab result is >1 IU/mL, then Thyroglobulin, LC/MS/MS will be performed at an additional charge (CPT 84432). By ordering this test the clinician acknowledges that additional reflex testing will be performed and billed at a separate additional charge if indicated. Test sent to Quest Diagnostics Nichols Institute of Valencia.