Of the following, which will MOST likely interfere with quantitation of thyroglobulin?

Of the following, which will MOST likely interfere with quantitation of thyroglobulin?

• A. Antithyroglobulin autoantibodies
• B. Thyroid-stimulating antibodies
• C. TSH receptor antibodies
• D. Thyroid peroxidase antibodies

Answer: (A)

Immunoassay measurements of thyroglobulin are particularly vulnerable to antibodies that target thyroglobulin itself. Antithyroglobulin autoantibodies can bind to thyroglobulin in the sample or bind to the assay’s components, blocking or altering the capture and detection steps. This can lead to falsely low or falsely high thyroglobulin readings, depending on the assay design and binding dynamics. Because these autoantibodies directly recognize thyroglobulin, they are the most likely source of interference among the options provided. The other antibodies listed target different parts of the thyroid system and do not routinely interact with thyroglobulin in a way that disrupts its measurement in a typical assay. Therefore they are less likely to cause interference with thyroglobulin quantitation.

Immunoassay measurements of thyroglobulin are particularly vulnerable to antibodies that target thyroglobulin itself. Antithyroglobulin autoantibodies can bind to thyroglobulin in the sample or bind to the assay’s components, blocking or altering the capture and detection steps. This can lead to falsely low or falsely high thyroglobulin readings, depending on the assay design and binding dynamics. Because these autoantibodies directly recognize thyroglobulin, they are the most likely source of interference among the options provided.

The other antibodies listed target different parts of the thyroid system and do not routinely interact with thyroglobulin in a way that disrupts its measurement in a typical assay. Therefore they are less likely to cause interference with thyroglobulin quantitation.