Anti-Thyroid Peroxidase (TPO) Antibody, Serum  

Synonym Anti-microsomal antibody
Specimen requirement Adult patient:

  Clotted blood tube (Serum gel separator clot activator tube)

Minimum blood volume: 5 mL
Paediatric patient:

Paediatric clotted blood tube

Number of vials: 2

Minimum blood volume: 1.6 mL
Authorisation code required No
24 Hr available service No
Method Immunoassay
Reference interval

< 15 kIU/L

(Source: from manufacturer's kit insert)

Clinical indication

Aid in the diagnosis of autoimmune thyroid disease.

Result interpretation

Circulating antibodies to thyroid peroxidase (TPO) are considered the best serological marker to establish a diagnosis of Hashimoto thyroiditis. They are elevated in virtually all patients with Hashimoto thyroiditis and in the majority of Graves’ disease patients.

Anti-TPO antibodies also occur in low titre in 10% of healthy individuals without apparent thyroid disease.

Patients with Anti-TPO antibodies detected in early pregnancy are at risk for developing post-partum thyroiditis.
Measurement of uncertainty

N. A.
Frequency of measurement Daily