Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX
For diagnosing autoimmune thyroiditis in primary care, the essential laboratory tests typically involve assessing thyroid function and specific antibodies:
- Initial Thyroid Function Tests (TFTs):
- For adults where secondary thyroid dysfunction (pituitary disease) is not suspected, consider measuring thyroid-stimulating hormone (TSH) alone NICE NG145. If the TSH is above the reference range, free thyroxine (FT4) should be measured from the same sample NICE NG145.
- For children and young people, or adults where secondary thyroid dysfunction is suspected, consider measuring both TSH and FT4 NICE NG145.
- These tests may be repeated if symptoms worsen or new symptoms develop, but no sooner than 6 weeks from the most recent test NICE NG145.
- Thyroid Peroxidase Antibodies (TPOAbs):
- To identify autoimmune thyroiditis, consider measuring thyroid peroxidase antibodies (TPOAbs) for adults with TSH levels above the reference range NICE NG145. TPOAbs testing should not be repeated NICE NG145.
- For children and young people with TSH levels above the reference range, TPOAbs should be measured NICE NG145.
- Positive TPOAbs indicate an increased risk of primary hypothyroidism NICE CKS. They are also associated with an increased risk of a more severe episode of postpartum thyroiditis and a higher likelihood of postpartum hypothyroidism NICE CKS.