Test Code LAB2011 Thyroglobulin Panel (TG)
Additional Codes:
TG
Collection:
Specimen: Blood
Container: Plain Red
Volume: 4 mL; Minimum 2 mL
Pediatric Collection:
3 Red microtainers filled to 600 uL.
Storage Instructions:
Serum should be separated from red cells when stored or shipped. Specimens that cannot be tested immediately can be refrigerated up to 48 hours. For storage beyond 48 hours, specimens should be frozen.
Turnaround Time (TAT):
Results reported on day of testing
Test Availability:
Batched twice per week – Days vary
Performing Laboratory Section:
Special Chemistry / UMC Main Laboratory
Send To:
UMC MAIN LABORATORY Specimen Receiving – EH319 Hospital Extension
Reference Interval:
Intact Thyroid: < 33 ng/mL
Note: In athyrotic individuals, Tg levels should be <0.1 ng/mL
Interpretive Data:
Tg levels should be interpreted in the context of TSH level, radioiodine ablation status and serial Tg measurements. Athyrotic individuals on suppressive therapy with Tg levels <0.1 ng/mL have very low risk (<2%) of clinically detectable recurrent differentiated thyroid cancer (DTC). Tg levels are measured on Beckman Access, a second generation IMA (2G-IMA) with functional sensitivity of 0.1 ng/mL. This assay should not be used in patients with detectable anti-thyroid antibodies (Tg Ab) as it may result in falsely low Tg results due to assay interference. Patients with detectable Tg Ab are reflexed to a Tg by LC-MS/MS method that is resistant to Tg Ab interference. Note: For patients taking 20 mg/day or more of biotin there is a potential of falsely decreased results.