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Test Code HTG2 Thyroglobulin, Tumor Marker, Serum

Useful For

Follow-up of patients with differentiated thyroid cancers after thyroidectomy and radioactive iodine ablation

Reporting Name

Thyroglobulin, Tumor Marker

Specimen Type

Serum Red


Ordering Guidance


For accurate analysis of patients who are known to be thyroglobulin antibody positive, order TGMS / Thyroglobulin Mass Spectrometry, Serum.



Specimen Required


Patient Preparation:  For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Red top (serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Refrigerated (preferred) 7 days
  Frozen  30 days
  Ambient  7 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus Reject

Reference Values

Thyroglobulin Tumor Marker

Athyrotic: <0.1 ng/mL

Intact thyroid ≤33 ng/mL

 

Thyroglobulin Antibody:

<1.8 IU/mL

Reference values apply to all ages.

Method Description

The Beckman Coulter Unicel DxI 800 is used for both thyroglobulin tumor marker and thyroglobulin antibody testing.

 

The Access Thyroglobulin (Tg) assay is a simultaneous 1-step immunoenzymatic (sandwich) assay. A sample is added to a reaction vessel, along with a biotinylated mixture of 4 monoclonal anti-Tg antibodies, streptavidin-coated paramagnetic particles, and monoclonal anti-Tg antibody alkaline phosphatase conjugate. The biotinylated antibodies and the serum Tg bind to the solid phase, while the conjugate antibody reacts with a different antigenic site on the Tg molecule. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then, the chemiluminescent substrate Lumi-Phos 530 is added to the vessel, and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of Tg in the sample.(Package insert: Access Thyroglobulin. Beckman Coulter Inc; 10/2023)

 

The Access Thyroglobulin Antibody II assay (TgAb) is a sequential 2-step immunoenzymatic (sandwich) assay. A sample is added to a reaction vessel with paramagnetic particles coated with the thyroglobulin protein. The serum TgAb binds to the thyroglobulin. After incubation in a reaction vessel, materials bound to the solid phase are held in place by a magnetic field, while unbound materials are washed away. The thyroglobulin-alkaline phosphatase conjugate is added and binds to the TgAb. After the second incubation, materials bound to the solid phase are held in place by a magnetic field, while unbound materials are washed away. Then, the chemiluminescent substrate, Lumi-Phos 530 is added to the reaction vessel, and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of thyroglobulin antibody in the sample.(Package insert: Access Thyroglobulin Antibody II. Beckman Coulter Inc; 07/2021)

Day(s) Performed

Monday through Saturday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

84432

86800

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HTG2 Thyroglobulin, Tumor Marker 57780-9

 

Result ID Test Result Name Result LOINC Value
TGAB2 Thyroglobulin Antibody, S 56536-6
HTGN2 Thyroglobulin, Tumor Marker, S 3013-0
HTG2I Thyroglobulin Interpretation 69053-7

Method Name

Immunoenzymatic Assay

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Oncology Test Request (T729)

Secondary ID

62800