What is the meaning of TPO-antibody?

Thyroid peroxidase or thyroperoxidase (TPO) is an enzyme mainly expressed in the thyroid that liberates iodine for addition onto tyrosine residues on thyroglobulin for the production of thyroxine (T4) or triiodothyronine (T3) (thyroid hormones).[1] In humans, thyroperoxidase is encoded by the TPO gene.[2]