Autoantibody against thyroid peroxidase. Present in Hashimoto's thyroiditis and Graves' disease. High titres indicate increased risk of progression to hypothyroidism.
| Sex | Age | Range | Notes |
|---|---|---|---|
| All | ≥ 18 yrs | < 35 | Negative <35; equivocal 35–60; positive >60 (lab-specific) |
⚠ Clinical Note
Reference ranges are indicative. Always interpret results in the context of the individual patient and local laboratory reference intervals, which may vary.