1st order laboratory parameters – obligatory laboratory tests.
- Thyroid parameters – TSH (thyroid-stimulating hormone), fT3 (triiodothyronine), fT4 (thyroxine)[At onset: latent hyperthyroidism (hypothyroidism): TSH ↓, fT3 normal, fT4 possibly. slightly to moderately elevated; In the course: manifest hypothyroidism: TSH level ↑, fT3 + fT4 decreased; manifest hyperthyroidism (hyperthyroidism) is rare]
Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.
- TPO antibodies (TPO-Ak; thyroid peroxidase; MAK) [detection frequency: 90%]Note in pregnancy: detection of TPO antibodies even in euthyroidism (normal thyroid function) with high predictive power: in 19-50% of women it comes postpartum (“after birth”) to manifest hypothyroidism (hypothyroidism).
- Tg antibodies (Tg-Ak; thyroglobulin autoantibodies (TGAK); thyroglobulin-Ak; TAK) [detection frequency: 60-70%]
- TRAK (TSH receptor autoantibodies) [detection frequency: <10%] N.B.: In Graves’ disease, TSH receptor antibodies (TRAK) are found in 95% of cases in the acute stage.
Note: As the disease progresses, thyroid antibodies may return to normal.