TPO and Abnormality of the thyroid gland: The association with hypothyroidism, positive anti-TPO, and ultrasonographic findings (thyroid hypoechogenicity) has been previously demonstrated.18, 19 There was no association of PA in the assessed sample, considering hypothyroidism (p = 0.65), anti-TPO (p = 0.76), or thyroid abnormality (p = 0.87).