**Background of TH Antibodies**
Thyroid hormone (TH) antibodies, also known as thyroid autoantibodies, are immune proteins that mistakenly target components of the thyroid gland or thyroid hormones. They are primarily associated with autoimmune thyroid disorders, such as Hashimoto's thyroiditis and Graves' disease. Key types include thyroid peroxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb), and thyroid-stimulating hormone receptor antibodies (TRAb).
TPOAb and TgAb are markers of autoimmune thyroiditis, often linked to hypothyroidism, while TRAb stimulates the thyroid receptor, causing hyperthyroidism in Graves' disease. These antibodies arise from immune dysregulation, where genetic predisposition (e.g., HLA variants) and environmental triggers (e.g., iodine, infections) disrupt immune tolerance.
Clinically, TH antibodies aid in diagnosing autoimmune thyroid conditions, predicting disease progression, and assessing risks (e.g., miscarriage in pregnancy). Their detection involves immunoassays like ELISA or chemiluminescence. Research continues to explore their pathogenic mechanisms, including cytokine involvement and tissue destruction pathways, as well as therapeutic targets to modulate autoimmune responses. Understanding TH antibodies remains vital for managing thyroid dysfunction and improving patient outcomes.