Which antibodies are associated with autoimmune thyroiditis (Hashimoto's disease)?

• A. Thyroid peroxidase antibodies only
• B. Anti-TSH receptor antibodies
• C. Calcitonin antibodies
• D. Thyroid peroxidase and antithyroglobulin antibodies

Answer: (D)

Hashimoto's disease involves an autoimmune attack on the thyroid, with antibodies most commonly directed against thyroid antigens such as thyroid peroxidase and thyroglobulin. Anti-thyroid peroxidase (TPO) antibodies are the most sensitive and are present in the majority of patients, while anti-thyroglobulin antibodies are also commonly found and support the autoimmune etiology. Antibodies to the TSH receptor are typically linked to Graves' disease and thyrotoxicosis, not Hashimoto's. Calcitonin antibodies are not a characteristic feature of this condition. So the antibodies associated with autoimmune thyroiditis are those targeting thyroid peroxidase and thyroglobulin.