Thyroid UK
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Hashimotos antibodies - disappearing?

Good morning. I'm hoping someone might be able to tell me whether TPO antibodies can fluctuate so wildly that tests just 14 weeks apart can show a patient ( me) to be positive then negative? As the ranges are different ( different labs) they may not help much but here they are:

1/9/15: Ak g. Thyreoperoxidase (< 34 U/ml) * 165

14/12/15 ac. anti-TPO (< 5.6 Ul/ml) < 3.0

Would testing blood that had been stored for 7 days ( and more) affect the results? My daft doctor phoned the lab to ask for this 'extra' test to be done when I got angry with him. He phoned 7 days after my blood was first taken and the testing was done 10 days after my blood was first taken. I am waiting to hear from a lab tech I happen to know how long the labs usually keep samples but would there be some degradation? If blood had been frozen, unfrozen and then frozen and unfrozen again? I'm not a phlebotomist....anyone?

I have to say I felt lousy when the first set of blood was taken ( and hashimotos also confirmed with an ultrasound). I feel much less lousy in the breathing/throat department at the moment.

3 Replies

Catrich, There's not much point in retesting antibodies once it is established you have Hashimoto's. Antibodies fluctuate and will be higher after a recent Hashi attack and then subside until the next attack. Some people are diagnosed by ultrasound scan and may not even have positive antibodies.

Different testing techniques and ranges will give different results so it can be difficult to compare and see whether antibodies are rising or falling unless you use the same lab. I doubt the lab would have analysed week old blood if there was likelihood it would have degraded.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.


Thanks for responding Clutter. Given docs reluctance to test for antibodies and the high likelihood of their fluctuation, there must be a lot of people out there who never get disgnosed?

I wanted to see if there had been any change in the antibody count ( 3 months gluten free, liver cleanse etc etc) but I hadn't expected to see such a dramatic 'improvement'!!!

I have been reliably informed now by a couple of lab techs ( I teach lab techs so easy for me to grab one and interrogate!) that blood samples here are destroyed after one week. So my doctor was seemingly lucky to get the order in before my sample was binned! There is also no guarantee the lab will re-test using the sample - all depends on what test.


Catrich, I think you're right, a lot of people are never tested for Hashimoto's. Some doctors think there is no point because it doesn't alter treatment which is for hypothyroidism.

Certainly looks like the liver cleanse and g-f have been helpful for you.


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