Anti-TPO Antibody, plasma or serum

Alternate test name

Anti-Microsomal Antibody, Anti-Thyroid Antibody, Anti-Thyroid Peroxidase Antibody

Lab area

Clinical Biochemistry - General

Method and equipment

Equipment : Roche Cobas Pro e801

Method : Competition principle. Total duration of assay: 18 minutes.
▪ 1st incubation: sample are incubated with anti‑TPO‑antibodies labeled with a ruthenium complexa)
▪ 2nd incubation: After addition of biotinylated TPO and streptavidin‑coated microparticles, the anti‑TPO antibodies in the sample compete with the ruthenium‑labeled anti‑TPO antibodies for the biotinylated TPO antigen. The entire complex becomes bound to the solid phase via interaction of biotin and streptavidin.
▪ The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell II M. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier.
▪ Results are determined via a calibration curve which is instrument specifically generated by 2‑point calibration and a master curve provided via the cobas link.

Expected turn-around time

STAT/ Urgent/ Routine: 24 Hours

Specimen type

Serum or plasma heparin

Specimen requirements

150 uL

Storage and transportation

Shipping information

The Hospital for Sick Children

Rapid Response Laboratory

555 University Avenue, Room 3642

Toronto, ON

Canada

M5G 1X8

Phone: 416-813-7200

Toll Free: 1-855-381-3212

Hours: 7 days/week, 24 hours/day

Requisition

Anti-TPO Antibody, plasma or serum - requisition

Background and clinical significance

It was first demonstrated by Trotter et al. in 1957 and subsequently by Roitt and Doniach in 1958 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. They are also detectable at low levels in up to 20% of asymptomatic individuals, particularly the elderly and more often in women than in men, although the clinical significance of these autoantibodies is unclear.