Interference Evaluation Heterophile, Thyroglobulin Tumor Marker, Serum
Use
Evaluation of suspected interference from heterophile antibodies causing a falsely elevated thyroglobulin result. This test involves the evaluation of thyroglobulin (Tg) concentrations obtained by immunoassay, mass spectrometry, and following pretreatment with commercial heterophile blocking reagents. It is crucial for detecting false-positive results in immunoassays due to heterophile antibodies that might interfere with the assay's accuracy. Heterophile antibodies may lead to erroneous clinical interpretations and management decisions.
Special Instructions
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.
Limitations
This assessment does not rule out the presence of other interfering substances such as biotin. Strong heterophile interference may not be fully blocked by heterophile blocking reagents. Specimens with very high Tg concentrations can lead to a 'hook' effect. Results across different methodologies may vary, presenting challenges in direct comparisons. Rare amino acid variations can affect mass spectrometry results, potentially reducing apparent Tg concentrations by half in heterozygote states or causing complete signal loss in homozygote states.
New York Approved
Methodology
Immunoassay (Immunoenzymatic Assay)
Biomarkers
LOINC Codes
- 101626-0
- 3013-0
- 59462-2
- 56536-6
- 96460-1
- 101627-8
- 101628-6
Result Turnaround Time
3-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
2.5 mL
Minimum Volume
2 mL
Container
Red top (serum gel/SST are not acceptable)
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Patient Preparation
For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements containing biotin (vitamin B7).
Causes for Rejection
Gross hemolysis, Gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 7 days |
| Frozen | 30 days |