Anti-TPO antibodies
Anti-TPO antibodies, also known as thyroid peroxidase antibodies or thyroperoxidase antibodies, are autoantibodies that target thyroid peroxidase, an enzyme involved in the production of thyroid hormones. Testing for anti-TPO antibodies is primarily used in the evaluation of thyroid disorders, particularly autoimmune thyroid diseases, including:
- Hashimoto's Thyroiditis: Hashimoto's thyroiditis is an autoimmune condition characterized by chronic inflammation of the thyroid gland, leading to hypothyroidism. Anti-TPO antibodies are typically elevated in individuals with Hashimoto's thyroiditis. Measuring anti-TPO antibodies can aid in the diagnosis of Hashimoto's thyroiditis, particularly in individuals with subclinical or early-stage disease.
- Graves' Disease: While Graves' disease is primarily associated with the presence of thyroid-stimulating immunoglobulins (TSIs) that stimulate thyroid hormone production, some individuals with Graves' disease may also have elevated levels of anti-TPO antibodies. The presence of anti-TPO antibodies in Graves' disease may indicate concurrent autoimmune thyroiditis or an overlap syndrome with Hashimoto's thyroiditis.
- Autoimmune Thyroiditis: Anti-TPO antibodies are commonly elevated in autoimmune thyroiditis, a spectrum of autoimmune thyroid diseases that includes Hashimoto's thyroiditis and atrophic thyroiditis. Measuring anti-TPO antibodies can help confirm the autoimmune nature of thyroiditis and guide treatment decisions.
- Predicting Thyroid Dysfunction: Elevated levels of anti-TPO antibodies, particularly in the absence of symptoms, may indicate an increased risk of developing thyroid dysfunction, such as hypothyroidism or hyperthyroidism, in the future. Monitoring anti-TPO antibody levels over time may help identify individuals at risk of thyroid dysfunction and guide preventive interventions or early treatment.
- Monitoring Autoimmune Thyroid Disease: In individuals with autoimmune thyroid disease, monitoring anti-TPO antibody levels over time can provide valuable information about disease activity and response to treatment. Decreasing levels of anti-TPO antibodies may indicate a favorable response to treatment, while persistently elevated levels may suggest ongoing autoimmune activity or the need for adjustments in treatment.