Related Experiment Video
Updated: Feb 24, 2026

Generation of a Mouse Spontaneous Autoimmune Thyroiditis Model
Published on: March 17, 2023
Avoiding Misdiagnosis Due to Antibody Interference with Serum Free Thyroxin
Pilar I Beato-Víbora1, S Alejo-González2
1Department of Endocrinology, Badajoz University Hospital, Badajoz, Spain.
Introduction:
Interfering antibodies are capable of causing potentially misleading results in automated thyroid hormone immunoassays.
Case Presentation:
We report the case of a 46- year-old female patient with autoimmune hypothyroidism in chronic replacement treatment with levothyroxine who was presented 8 years after diagnosis with a thyroid function test showing an increased level of TSH and a very high level of FT4. Interference in the laboratory serum free thyroxin (FT4) test was suspected, due to the lack of symptoms of hyperthyroidism and a different immunoassay platform confirmed a low FT4 result. The discrepancy between the two results was explained by the presence of antiT4-autoantibodies.
Conclusions:
Antibody interference with serum free thyroxine must be considered when clinical findings and laboratory results show discrepancies.
More Related Videos
05:41Author Spotlight: Integrating Ultrasound Imaging with Biochemical Markers for Thyroid Disease Diagnosis
Published on: February 9, 2024
06:50A High-Throughput Electrochemiluminescence 7-Plex Assay Simultaneously Screening for Type 1 Diabetes and Multiple Autoimmune Diseases
Published on: May 29, 2020
Related Concept Videos
Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The...
Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...