Help interpreting Thyroglobulin and Thyroglobulin Antibodies Test from Endocrinologist

[ShonaGreen]

Hi,

The endocrinologist ordered thyroglobulin and thyroglobulin antibodies tests, see the picture for info. I received these today with a note from the secretary that they were within normal limits. But there's no reference ranges and I've tried to search for more info on the internet but it all relates to persons being treated for thyroid cancer which I'm not.

When I've had other tests done for thyroglobulin antibodies, the reference range is usually >115 and my results are usually in the 200's, so unsure how to interpret a result of 9?

I've not had a thyroglobulin test before so not sure of the reference of this?

Any info you can share with me would be most appreciated, as I've learned now not to always trust a result that's within normal limits!

[SeasideSusie Remembering]

They can't be interpreted without the lab's ranges, and the internet wont have ranges that would be specific to your lab, so if I were you I'd ring the secretary again and say you would like the actual numbers of the ranges, if she repeats that they're within normal limits say that you understand that but you want to know the actual numbers.

[ShonaGreen in reply to SeasideSusie]

Thanks SeasideSusie , I've contacted the secretary to ask this, just wondering why he'd order these tests as don't seem applicable to me, but we'll see what he says!

[SlowDragon Administrator]

The image says "Thyroglobulin antibodies positive "

If you don't get anywhere with endocrinologist, suggest you get private testing

[Poniesrfun]

Thyroglobulin is normally checked only if you have had thyroid cancer and had a thyroidectomy. After surgery the level should be undectable or very low; high or incrasing levels can mean reoccurence or metastasis of the thyroid cancer.

Its used only occasionally if someone is hyperthyroid.

Thyroglobulin antibodies can interfere with the thyroglobulin test; if antibodies are detectable then the thyroglobulin test should be done using the more sensitive mass spectrometry method.

Do you have a thyroid or have you had surgery or RAI?

Patti in AZ

[ShonaGreen in reply to Poniesrfun]

Hi Poniesrfun , thanks for your message. Yes I do have a thyroid and no surgery for RAI, so am not sure why this test was done? I'm sure all is fine as the results are normal, but I'd like to know the reference ranges, and whether a low thyroglobulin result is good? Also looks like a low positive result for thyroglobulin antibodies?

[Poniesrfun]

US reference for thyrogloibulin is 1.5-38.5 ng/mL and the same in ug/L. But reference range is generally not relevant as it is being used as a cancer marker and should be undetectable. Almost everyone with a thyroid gland will have some thyroglobulin.

The thyroglobulin antibodies may indicate autoimmune thyroid disease but isn't as diagnostic as thyroid peroxidase antibodies. US reference is 0 to 0.9 IU/mL, same in kU/L.

If you are taking biotin, either alone or in a B-complex supplement, this can falsely elevate test results (except TSH, which can be falsely lowered). I usually stop any B-vitamins for at least 48 hours before tests.

healthcare.uiowa.edu/path_h...

Patti in AZ

[ShonaGreen]

That's very helpful info Poniesrfun , thanks again! I've requested the reference ranges but the secretary is away at the moment. So I guess in most reference ranges, a result of 1.6 for thyroglobulin is good but I wondered if this relates to the size of the thyroid? Could this also show that I don't have a problem with my thyroid?