Anti Thyroglobulin Interferences in TSH Measurement, A Case Report

Thyroglobulin (Tg) is the most expressed protein in the thyroid gland that stores iodine and produces thyroid hormones. Tg production is specific to malignant thyroid cells, making it an ideal indicator after removing thyroid tissue. As a result, it is used as a tumor marker post-surgery to assess any disease recurrence. The presence of Thyroglobulin antibody (TgAb) which is produced in autoimmune diseases can interfere with Tg value. The evaluation of plasma TSH levels is a highly sensitive diagnostic method for primary thyroid-related issues, although it can be affected by various interferences. in the present case, the high titer of TgAb interferes with TSH measurement as well as leads to unreliable Tg results.