I am 8 months post-RAI and my Endo decided to do TSI. My result came back as 470 (cut of 140). My Free T3 and Free T4 normal and TSH 0.02.
What does the TSI mean? I know before the RAI my TSI was about 370. Any feedback would be great! Thanks everyone.

Hello - We're fellow patients here, not docs, but here is some general information. The TSI test picks up the antibodies (thyroid stimulating immunoglobulins) that cause hyperthyroidism in Graves' disease.

One study showed that antibodies can spike for a period of 6-12 months following RAI treatment for Graves'.

(Note on links: if you click directly on the following link, you will need to use your browser's “back” button to return to the boards after viewing, or you will have to log back in to the forum. As an alternative, you can right-click the link and open it in a new tab or new window).

http://www.eje.org/content/158/1/69.full [eje.org]

One theory is that this might be why patients who receive RAI have a higher risk of eye complications…although there is a competing theory that what really increases the risk is if doctors allow patients to go hypO after RAI.

Hope this helps - take care!

Kimberly
One theory is that this might be why patients who receive RAI have a higher risk of eye complications…

Good information. That would make sense.

Caro

Wow! Thank you Kimberly! This is the answer I was looking for. I had read the suggestions that RAI could worsen the development of GO (Graves' Ophthalmopathy) compared to the other treatment options….but was wondering what the mechanism was. This makes sense!

Did you pick up the stat “with the disappearance of TRAb in 70–80% of the patients after 18 months”???

That's what my Endo said but I wasn't sure if I should believe such a high percentage! Well, actually what she said was, 70% of people treated with ATDs can have a durable remission after ~18 mos of treatment. I later learned that this rate is dependent on geography. Why? Is it compliance to meds??

Anyways, this EJE study says TRAb disappeared in 70-80% but it doesn't say for how long. It does say “After stopping therapy, around 40% of medically treated patients experienced a reactivation of TSH-receptor autoimmunity and became hyperthyroid again.” So, that's a bummmer…..but I guess overall, 60% of patient's will have long lasting remission?

I'm not sure what to make of this study, quite frankly. From my limited reading of studies recently on this topic, there is typically a caveat: That TRAb levels are NOT predictive of cure/remission or of development of TED. So, while this particular study seems to be showing the possibility of remission being read into it, but other studies don't necessarily support that… We perhaps need to curb our enthusiasm.

Over the years I've seen studies that come out of one part of the world that cannot be duplicated in other parts of the world, so apparently geography and ethnicity can matter.

I would also point out that this study used block and replace, and the doses of methimazole that were given were HUGE (10mg four times a day). Since you are looking for a way to get pregnant sooner, rather than later, this dose of ATD might not be safe for the developing baby. You need to check this carefully with all your doctors, Mickiko.

@Mickiko - I have not seen any studies that showed a remission rate as high as 70% for 18 months of ATD treatment, but if your doc has additional info on this, I would love to take a look!

@Bobbi - The latest guidance from the ATA and AACE indicates there is some predictive value of antibody testing when it comes to weaning off of Anti-Thyroid Drugs: “Measurement of TRAb levels prior to stopping antithyroid drug therapy is suggested, as it aids in predicting which patients can be weaned from the medication, with normal levels indicating greater chance for remission.” Also, this guidance notes that high antibody levels are a risk factor for worsening of the eye disease following RAI (along with smoking and high T3 levels). And many docs (although this is a subject of some contoversy) use antibody testing to determine when a patient with TED is entering the “cold” phase.

Certainly, the correlation isn't perfect, as the wording is somewhat guarded: “…chance for remission…”, “…risk factors…”, etc. – but it is believed that there is some correlation between antibody levels, TED, and the possibility of remission.

Just lost my post. aarrggh.

In an endocrine journal from the UK, the study –or abstract – title being something like Use of antithyroid hormone receptor (TRAb) in Graves, the researchers specifically stated: “TRAB did not seem to predict chance of cure, or development of GO.” Nothing equivocal about that one. But that is based on the results of a single study. And I don't know how good it was.

Also, the study you initially cited stated that TRAb declined in the blood regardless of treatment method.

So, I am still left scratching my head. I suspect that it is still a working hypothesis (unless that's a redundant phrase), subject to change.

Bobbi
Also, the study you initially cited stated that TRAb declined in the blood regardless of treatment method.

Hi Bobbi - Yes, over time, the antibody levels declined with all three treatment options. However, RAI was the only treatment option with a spike in antibody levels post-treatment. The peak occurred at about 6 months, and TRAb levels returned back to where they started before treatment at about 12 months. Then from that point, they start to decline.

I read some where, I don't remember where, about a study that said something about achieving remission from being euthyroid for a while and not necessarily from the Rx/treatment itself.

Hi Caro - This has been a subject of controversy among researchers. Do the anti-thyroid drugs have a direct immunosuppressive effect…or does achieving a euthyroid state cause antibody levels to decline? To my knowledge, this issue has not been conclusively decided one way or another.