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HelpOrder Code IETG Interference Evaluation Heterophile, Thyroglobulin Tumor Marker, Serum
Ordering Guidance
If interference or heterophile testing is not required, order HTG2 / Thyroglobulin, Tumor Marker, Serum.
For fine-needle aspirate specimens, order TFNAB / Thyroglobulin, Tumor Marker, Fine-Needle Aspiration Biopsy Needle Wash.
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:
Preferred: Red top
Acceptable: None (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 2.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Useful For
Evaluation of suspected interference from heterophile antibodies causing a falsely elevated thyroglobulin result
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| TGII | TG, Interference Interpretation | No | Yes |
| TGQN | Thyroglobulin, Tumor Marker, S | Yes, (Order HTG2) | Yes |
| TGABI | Thyroglobulin Antibody, S | Yes, (Order HTG2) | Yes |
| TGMS | Thyroglobulin, Mass Spec., S | Yes | Yes |
Testing Algorithm
Heterophile antibody evaluation consists of comparison of thyroglobulin (Tg) concentrations obtained by immunoassay with the following:
-Tg concentrations following pretreatment with commercial heterophile blocking reagents
-Tg concentrations obtained by mass spectrometry
-Tg concentrations obtained by serial dilutions of the sample
In all samples the presence of anti-thyroglobulin antibodies are evaluated.
Method Name
TGII: Medical Interpretation
TGQN/TGABI: Immunoenzymatic Assay
TGMS: Tryptic Protein Fragmentation, purified with Immunocapture, Analysis by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
(This service is performed pursuant to an agreement with SISCAPA Assay Technologies Inc. covering US Patent 7,632,686)
Reporting Name
Interference Eval, Heterophile, TGSpecimen Type
Serum RedSpecimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum Red | Refrigerated (preferred) | 7 days |
| Frozen | 30 days | |
| Ambient | 72 hours |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | Reject |
Reference Values
THYROGLOBULIN TUMOR MARKER
≤33 ng/mL
THYROGLOBULIN, MASS SPECTROMETRY
≤33 ng/mL
THYROGLOBULIN ANTIBODY
<1.8 IU/mL
Reference values apply to all ages.
Method Description
The specimen will be evaluated for potential heterophile antibody interference in the Beckman Coulter Access Thyroglobulin Immunoassay. Heterophile antibody evaluation will consist of measurement of thyroglobulin antibody, pretreatment with commercial heterophile antibody blocking reagents, testing on an alternate platform liquid chromatography tandem mass spectrometry, and serial dilution of the sample.
Heterophile blocking agents consist of HBT (Heterophile Blocking Tube) - Scantibodies Incorporated for the Beckman Assay. This blocker contains murine (HBT) derived proteins in a buffered salt solution.
Thyroglobulin, Tumor Marker:
The Beckman Coulter UniCel DxI 800 is the instrument used for thyroglobulin tumor marker testing. The Access Thyroglobulin (2) assay is a simultaneous one-step immunoenzymatic (sandwich) assay. the sample is added to a reaction vessel, along with a biotinylated mixture of four monoclonal anti- thyroglobulin (Tg) antibodies (TgAb), streptavidin-coated paramagnetic particles, and monoclonal anti-Tg antibody alkaline phosphatase conjugate. The biotinylated antibodies and the serum thyroglobulin bind to the solid phase, while the conjugate antibody reacts with a different antigenic site on the thyroglobulin 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 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 thyroglobulin in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve(Package insert: Access Thyroglobulin. Beckman Coulter Inc.; 09/2024).
Thyroglobulin Antibody:
The Access Thyroglobulin Antibody II assay is a sequential 2-step immunoenzymatic (sandwich) assay. The sample is added to a reaction vessel with paramagnetic particles coated with Tg 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 Tg-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 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 TgAb in the sample. The amount of analyte in the sample is calculated by means of a stored, multi-point calibration curve(Package insert: Thyroglobulin Antibody II. Beckman Coulter Inc; 09/2024).
Thyroglobulin, Alternative Method:
Serum is fractionated by a salting out method. Fractionated serum is then reduced, alkylated, and digested with trypsin. Tryptic fragments are further purified by immunocapture with antibodies specific to the individual fragments. Finally, these fragments are analyzed by liquid chromatography tandem mass spectrometry.(Unpublished Mayo method)
Thyroglobulin, Interference Interpretation:
A laboratory director will review the results and provide an interpretation.
Day(s) Performed
Monday through Saturday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
84432
86800
84432