Hypothyroid with TSI antibodies?

[Drea811]

I would really appreciate it if someone could give me some guidance/ their opinions on this! I am a 33-yr-old female. A couple years ago I began presenting with some symptoms of hyperthyroidism, mainly heart palps, very increased heart rate and sweating. In testing my thyroid at that time, my TSH was in the low range (.7) but normal according to lab values. Just two weeks later, I was undergoing blood testing for a different matter at the Mayo Clinic, and they drew my blood to discover my TSH was now 17.3.

After that time, my TSH ping-ponged back and forth, usually falling at around 4 or 5. My doctors 'watched' me as I was subclinical hypothyroid and I was not symptomatic. During this time though, I was tested multiple times for TSI and TPO antibodies. TPO was always negative, but my TSI were occasionally high... sometimes around 120-125 (normal range), other times as high as 175. I also had a thyroid scan which showed increases blood flow to the thyroid in a pattern suggestive of Hashi's (not Graves).

When I became pregnant recently, I was put on Synthroid. I'm now currently stable at around 2, with higher-end normal T3/ T4 values.

My question: is it possible to be hypothyroid with TSI antibodies? Do I have Hashi's, Grave's or both... and why aren't TPO antibodies showing up if I indeed do have Hashi's?

Would really appreciate a response. My endocrinologists seem stumped... or at least, they haven't been able to adequately explain this matter or suggest further tests.

Thanks!

[Drea811]

Thanks Barb135! I don't have my reports in front of me now but I know my free T3 and free T4 have always been within the normal limits, even with the see-sawing going on. Right now they're both at the high end range of normal (which is where my OB and endo want them during my pregnancy) but since I don't have my labs with me, not sure of the exact values. Also, no nodules on my scan but that's an interesting hypothesis... I will ask about this during my next visit.

I don't believe I've ever been tested for TGab so I will look into that. Thanks a lot for that lead... Boy, this can be frustrating for sure! I have seen literally 3 different endocrinologists about this, and I'm surprised no one has raised the TGab issue before.

[Barb135]

I'm not real familiar with hyper, but I do know that TSI is the one done to test for Graves.  Do you know if you were tested for Thyroglobulin antibodies (TGab).  That's another one used to confirm Hashi's.  You might check your lab report for that and if it's not there, you should ask for it.  My endo tests both TPOab and TGab.  

What are your actual thyroid hormone levels?  Free T3 and Free T4.  Those are what will really tell you what's going on.  

Do you know if the thyroid scan showed nodules?  If so, it's possible that the nodules are leaking hormone, causing you to "seesaw" up and down.  But if your doctor is using only your TSH to determine what's going on, you have a recipe for disaster going on.