Quantitative Thyroglobulin without Thyroglobulin Antibodies

Test Code

THYGL

Quest Code

15561

CPT Codes
84432

Preferred Specimen

1 mL serum

Minimum Volume

0.5 mL

Instructions

Administration of STRENSIQ may interfere in certain assays and may falsely elevate values. For patients receiving STRENSIQ, consideration should be given to using alternate methods.

Transport Container

Serum Separator Tube (SST)

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days

Methodology
Immunoassay (IA)

Setup Schedule

Night shift Mon-fri

Report Available

1 day

Reference Range

Intact Thyroid	2.8-40.9 ng/mL
Athyrotic	<0.1 ng/mL

Note: Abnormal flagging is based on the reference interval for patients with intact thyroid.

Clinical Significance

Thyroglobulin (TG) is a secretory product only of the thyroid gland. The major clinical use of serum TG measurement is to monitor, but not to diagnose, patients with well-differentiated thyroid cancers. The measurement of thyroglobulin, after thyroidectomy and ablation of the thyroid gland, is useful to determine metastasis. Deficient TG synthesis is observed in infants with goitrous hypothyroidism. With immunometric assays (sandwich assays), TGAB interference typically produces inappropriately low TG results, most likely caused by endogenous TG immune complexes that block one or more of the reagent Ab from binding endogenous TG.

Performing Laboratory

Quest Diagnostics LLC

200 Forest Street 3rd Floor, Suite B

Marlborough, MA 01752-3023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.