Hashimoto's thyroiditis commonly presents with which thyroid autoantibody?

Hashimoto's thyroiditis commonly presents with which thyroid autoantibody?

• A. Thyroglobulin antibodies
• B. Thyroid peroxidase antibodies (anti-TPO)
• C. TSH receptor antibodies
• D. No antibodies present

Answer: (B)

Hashimoto's is an autoimmune thyroiditis where the immune system attacks the thyroid, leading to gradual destruction and often hypothyroidism. The most characteristic autoantibody is anti-thyroid peroxidase (anti-TPO). Thyroid peroxidase is essential for synthesizing thyroid hormones, so antibodies against it reflect immune-mediated damage to the thyroid. Anti-TPO antibodies are found in the vast majority of Hashimoto's patients, making them the most sensitive and supportive marker for this condition. Antibodies to thyroglobulin can occur, but they are less consistently present and less specific for Hashimoto's. TSH receptor antibodies are typically associated with Graves disease (which causes hyperthyroidism), though occasional overlap can occur; they are not the hallmark of Hashimoto's. So the presence of anti-TPO antibodies best fits the diagnosis.

Hashimoto's is an autoimmune thyroiditis where the immune system attacks the thyroid, leading to gradual destruction and often hypothyroidism. The most characteristic autoantibody is anti-thyroid peroxidase (anti-TPO). Thyroid peroxidase is essential for synthesizing thyroid hormones, so antibodies against it reflect immune-mediated damage to the thyroid. Anti-TPO antibodies are found in the vast majority of Hashimoto's patients, making them the most sensitive and supportive marker for this condition.

Antibodies to thyroglobulin can occur, but they are less consistently present and less specific for Hashimoto's. TSH receptor antibodies are typically associated with Graves disease (which causes hyperthyroidism), though occasional overlap can occur; they are not the hallmark of Hashimoto's. So the presence of anti-TPO antibodies best fits the diagnosis.