Anti-TPO ELISA

Anti TPO antibodies (formerly thyroid microsomal
antibodies) are directed against a target protein - thyroid
peroxidase (TPO) - located in the smooth endoplasmic
reticulum of thyroid cells.
Thyroid peroxidase or Thyroperoxidase (TPO) is an
enzyme mainly expressed in the thyroid that liberates
iodine for addition onto tyrosine residues on thyroglobulin
for the production of thyroxine (T4) or triiodothyronine (T3)
(thyroid hormones).
It is a frequent epitope of autoantibodies in autoimmune
thyroid disease. In autoimmune disorders, your immune
system makes antibodies that mistakenly attack normal
tissue such as thyroid peroxidase. Antibodies that attack
the thyroid gland cause inflammation and impaired function
of the thyroid.
The presence of anti-TPO antibodies in serum is
associated with thyroid autoimmune diseases (Graves'
disease and Hashimoto's thyroiditis). Anti-TPO antibodies
mostly belong to the IgG class.
Low to moderate levels of serum anti-TPO antibodies can
be found in some other autoimmune pathology (eg
systemic lupus erythematosus or Sjogren syndrome) and,
rarely, in apparently healthy subjects (especially elderly
women). Anti-TPO antibodies are more sensitive in
diagnostics of thyroid autoimmune diseases than antithyroglobulin
(anti-TG) antibodies.
However, in some cases anti-TG positive sera may be
negative for anti-TPO. Therefore, combined determination
of both types of anti-thyroid antibodies (anti-TPO + anti-TG)
provides a more sensitive laboratory diagnostic tool for
thyroid autoimmunity.