TPO antibodies

Understanding the marker

TPO antibodies react with an enzyme used to make thyroid hormones. They can help assess whether an immune reaction contributes to a thyroid condition.

Testing may be appropriate with raised TSH, for example. Antibodies can be present while hormone production is normal and do not automatically explain symptoms. Repeated antibody measurements are usually unnecessary for monitoring function.

What does a positive TPO antibodies result mean?

A positive TPO-antibody result can support an immune reaction involving the thyroid. Antibodies may be present without a current hormone imbalance. TSH and free T4 show a different part of the assessment.

What does a negative TPO antibodies result mean?

A negative TPO-antibody result makes this immune explanation less likely but does not exclude it. TSH, free T4 and symptoms are needed to assess thyroid function.