Which antibody is commonly present in Hashimoto's along with anti-TPO?

• A. Anti-thyroglobulin antibodies.
• B. Anti-TSH receptor antibodies.
• C. ANA.
• D. Anti-insulin antibodies.

Answer: (B)

Hashimoto's thyroiditis involves autoimmune attack on thyroid antigens, with anti-TPO antibodies being the common hallmark. A frequent accompanying antibody is anti-thyroglobulin, reflecting a broader autoimmune response against thyroid proteins. Antibodies against the TSH receptor are more typical of Graves' disease, where they stimulate the receptor and drive hyperthyroidism. Therefore, the antibody that commonly appears alongside anti-TPO in Hashimoto's is anti-thyroglobulin.