The answer is yes, you can have antibodies without effect on FT3 ,FT4 and TSH.
That is frequently seen in our laboratory. In Lemtrada treatment in MS it is reported up to 30% of patients that have elevated abs but are euthyroide. However it should be considered a risk for hyphothyreosis
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Yes it is not only possible but also frequent. It represents the marker that an inflammatory and autoaggressive event occurred in the thyroid. Thyroid, however, may not be completely destroyed and is still able to release iodothyronines in sufficient amount. As the time goes by, biochemical and overt hypothyroidism may occur.
Yes, also in my experience you can have high Anti-TPO levels while FT3 ,FT4 and TSH level are in range. This situation represents a risk for hypothyroidism.
Yes, it is possible. The name of the condition is euthyroid thyroiditis or isolated thyroididtis. Is has approximately 10-12% of prevalence, and corresponds- in the evolution natural of the thyroiditis of Hashimoto not treated-, usually to the second step, being the first, the change in the echogenicity at the US, the third, the increase of TSH, the fourth the descent of T4 and the final step, the descent of T3. This natural progression from the first stage to the last occurs at a rate of 5% per year. Reference, Fig. 5 page 49, Thyroid vol 13, no1, 2003.Laboratory Medicine Practice Guidelines for the Dagnosis and Monitoring of Thyroid Disease. In the Spanish Version, of which I am co-author, the first step is a changee in ecogenicity at US (preceding the rise of TPOAb), and still with TSH , T4 and T3 Total or Free in range. Best regards
I can only admire Lilianas brilliant answer and Salman is also right of course.T%he rise of antibody levels before any change can be seen in the organ attacked is quite a common phenomenom-take type 1 diabetes, for example