Hi Elaine, I hope you're well, and wish to thank you again for your invaluable resource here.
I was diagnosed with Graves in 2013 - I was apparently negative for the antibodies associated with Graves but I had TED and the uptake scan suggested Graves so that was the diagnosis.

After several years on varying amounts of Carbimazole, in July 2015 my FT4 and FT3 came into range and I began reducing my dose gradually, although contrary to my Endo's advice because I have had consistently low TSH. Finally, after a couple of months on 1/8 of a 5mg pill daily, I came off Carbimazole altogether in late March.

My thyroid function test in March before stopping Carbimazole was FT4 14.3 (8.8 - 18.8) and TSH >0.01 (0.4 - 4.5).
My blood test in June after 3 months of NO Carbimazole was FT4 13.9 (8.8 - 18.8) and TSH >0.01 (0.4 - 4.5).

I continue to take vitamin D and eat a largely Paleo diet (90% of the time), I exercise 5 times a week and walk a lot. I feel well and have no symptoms of Graves - I also feel my TED has improved (my eyes are protruding less which I am very pleased about).

My question is, do you think this has been Graves' disease despite negative antibodies, and if so, that I am in remission, and that eventually I will begin secreting TSH normally again?

Thank you in advance for your thoughts on this.

Best wishes

Rebecca

Hi Rebecca,

The TSI and even TRAb tests are subject to interpretation. I can't tell you how many people I've seen with positive results who were told their results were negative just because they were below the cutoff. This isn't always the case but often it is. Most tests measure TSI in terms of %activity with around 130% activity the level where hyperthyroidism develops. Normal people with no thyroid disease or family history of Graves' disease have levels that are <2% activity, which is negative. But you'll see people with levels of 80-120 being told that their results are negative.

In some cases people have TGI which are thyroid growth immunoglobulins rather than TSI antibodies but rarely is the TGI test ordered. So yes, you could have had Graves' disease and your low TSH suggests it. Both blocking and stimulating TSH receptor antibodies will falsely lower your TSH result. You can have a low TSH even with a move into hypothyroidism and many people don't begin secreting TSH for several years after they've achieved remission. I do think you're in remission and will eventually secrete TSH. best, elaine