Elevated thyroid peroxidase antibodies, or TPO-Ab, may indicate thyroid disease such as Graves’ disease, or other diseases such as rheumatoid disease and systemic lupus erythematosus. 1. Thyroid disease: Elevated TPO-Ab is commonly seen in autoimmune thyroiditis such as Graves’ disease. However, since 85% of patients with hyperthyroidism and hypothyroidism exhibit high levels of TPO-Ab, the combination of TPO-Ab and thyroglobulin antibodies is of greater value in the diagnosis of most autoimmune diseases of the thyroid gland. In addition, TPO-Ab may be elevated in patients with postpartum thyroiditis, atrophic thyroid, and some nodular goiter. 2. Other diseases: TPO-Ab may also be elevated in patients with rheumatoid diseases and systemic lupus erythematosus. When thyroid peroxidase antibodies are elevated, it is recommended that the patient consult a doctor promptly to determine the cause of the disease and then treat it.