# Thyroglobulin Antibodies



## teri2280 (Feb 7, 2012)

One of the last times I was at the endo, he said something along of the lines of that I have positive thyroglobulin antibodies (something like that, not sure on his exact wording - it's a question i've meant to post here but have forgotten until now) and because of that the thyroglobulin tests he runs will always come back positive, and to get an accurate test result my thyroglobulin tests will have to be sent to USC to be read, therefore resulting in a month or so wait for my test results.

I've been researching the net, and have found out that thyroglobulin antibodies are present when there is thyroid cancer present. Oh. My. Gosh. (I so want to scream DUH! right now, for those of you who have been following my story.  )
For those of you who don't know my story, I had a tt a month and a half ago, and a thyca diagnosis about a month ago after pathology came back.

I just want to go in there and scream at my endo, "I have thyroid cancer! Of course I'm going to have thyroglobulin antibodies! Don't order the test before RAI when you already know that there's a possibility that there's still stuff up there!" (And yes, thyroglobulin was ordered before my RAI - NO clue as to why since it was done before my post-surg follow up with him in the end of March!) UGH!!!! Sometimes I want to strangle that man!!

IS it possible that I have something in me that a thyroglobulin test will always come back positive? Or is it just like I'm thinking and an obvious answer of "You have thyroid cancer, of course you have thyroglobulin antibodies."?

Thanks folks, and sorry for all the posts tonight.


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## joplin1975 (Jul 21, 2011)

My understanding is that thyroglobin is only produced by the thyroid, therefore once all the tissue is destroyed, that number gets very, very low. I would expect you still have some now, but a few months after the RAI, it should dro significantly.

If you had autoimmune issues, I believe those antibodies could still be floating around, but those are different.


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## lainey (Aug 26, 2010)

Thyroglobin antibodies are not indicative of cancer. In some cases, people who have thyroid cancer also have very high levels of the antibodies but to my knowledge there is not a causal relationship. Thyroid tissue produces thryoglobin, and having the antibodies can occur in normal people.

It is important to test for thyroglobin antibodies when thyroid cancer is suspected because having them can skew the results of the thyroglobin test. Post surgery, thyroglobin is measured--if your thyroid is removed and RAI administered, you should have no active thyroid tissue left to produce thyroglobin. The presence of thyroglobin in a person who has been treated for thyca can indicate a regrowth of thyroid tissue. Many patients with thyca do not have antibodies to thyroglobin, making these test results straightforward. If the patient also has the antibodies to thyroglobin, this blood test marker then becomes less reliable--hence in your case, your lab tests have to be sent out to be read.


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