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Paediatric Laboratory Medicine

Anti-TPO, Blood

Clinical Significance

It was first demonstrated by Trotter et al. in 19571 and subsequently by Roitt and Doniach in 19582 that many patients with Hashimoto’s thyroiditis had detectable autoantibodies in their blood directed at a thyroid antigen distinct from thyroglobulin. This antigen was termed thyroid microsomal and it has since been demonstrated that most if not all anti-thyroid microsomal autoantibodies recognize thyroid peroxidase (TPO) It is common to find anti-TPO antibodies in the absence of autoantibodies to thyroglobulin, particularly in patients with small goitres and up to 64% of cases of autoimmune hypothyroidism have been reported to be associated with anti-TPO antibodies alone.18 In addition, anti-TPO antibodies are frequently found in patients with other autoimmune diseases such as Rheumatoid Arthritis, Addison’s Disease and Type I Diabetes.19-21 They are also detectable at low levels in up to 20% of asymptomatic individuals,22 particularly the elderly23 and more often in women than in men, although the clinical significance of these autoantibodies is unclear.

Test Name

Anti-TPO, Blood

Test Code



Biochemistry - Biochemistry


Abbott Ci4100

External Proficiency Testing


Turn Around Time

Monday to Friday

Specimen Type

Serum or Sodium/Lithium Heparin / EDTA plasma

Minimum Specimen Requirements

150 uL



Approval is not required

CPT Codes


Shipping and Contact Information

The Hospital for Sick Children
Rapid Response Laboratory
170 Elizabeth Street, Room 3642
Toronto, ON
M5G 2G3
Phone: 416-813-7200
Phone: 1-855-381-3212

Reference Range

< 35 IU/mL