What is considered a positive antibodies result? - Thyroid UK

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What is considered a positive antibodies result?

riariariaria profile image
18 Replies

Hi all, I am currently considered sub-clinical hypothyroid and my doctor has put me on levothyroxine. She said I should have an antibodies blood test, and at the time she said "people either have them (antibodies) or they don't". My results came back - TgAb is 53U/ml (range 0-60) and TPO is 50 U/ml (range 0-60). She told me I tested negative for antibodies and I saw the results on her screen and said "oh, they're quite close to the top of the range" and she said "oh no, they can be in the hundreds sometimes". I am confused as everything I've read online is contradictory. I think the "normal" range seems to depend entirely on where you live. Has anyone else had any similar experiences to this, or have any insight into what is actually considered a positive result? Thank you!

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SeasideSusie profile image
SeasideSusieRemembering

riariariaria

It's positive when the result is over the limit. So with your results and ranges:

TG: 53U/ml (range 0-60)

TPO: 50U/ml (range 0-60)

Technically they are negative. But as you say they are very close to the upper limit.

As antibodies fluctuate, and yours are quite high in range, my betting would be that at some point they would retest over range and confirm autoimmune thyroid disease.

I have had mine tested many times, both TG and TPO, and although the ranges are different from yours (they do vary from lab to lab, there is no standard range), mine have always been low, sometimes 6, sometimes 10, never over 12.

Some people can have Hashi's without raised antibodies.

But even if you do have raised antibodies, the treatment is for the resulting hypothyroidism so wont be any different. But what you can do is help reduce the antibodies by adopting a strict gluten free diet which has helped many members here. Gluten contains gliadin (a protein) which is thought to trigger autoimmune attacks so eliminating gluten can help reduce these attacks. You don't need to be gluten sensitive or have Coeliac disease for a gluten free diet to help.

Supplementing with selenium l-selenomethionine 200mcg daily can also help reduce the antibodies, as can keeping TSH suppressed.

riariariaria profile image
riariariaria in reply toSeasideSusie

Thank you SeasideSusie for your clear explanation and your advice. I think you may be right about testing positive in the future. I have just had a re-test done (the first was in May), so I will see what the results are. I do have other autoimmune issues and a strong family history of autoimmune disorders. I have just started the gluten free diet, as I've seen lots of people say it helps them. Thank you again :)

SeasideSusie profile image
SeasideSusieRemembering in reply toriariariaria

I do have other autoimmune issues and a strong family history of autoimmune disorders.

In that case Ria, I would bet good money that you do have Hashi's and that test was done when the antibodies had just dipped below the limit.

SilverAvocado profile image
SilverAvocado in reply toriariariaria

This is a test that can have false negatives. Antibodies are up and down all the time, and if the test its done on a down day, uoiukeill appear negative.

Like Seaside Susie, I don't have Hashimotos, and my results tend to be around 12 or below.

SlowDragon profile image
SlowDragonAdministrator

So you have started on 50mcg Levothyroxine. Bloods need retesting in 6-8 weeks

For full Thyroid evaluation you need TSH, FT4, TT4, FT3 plus TPO and TG thyroid antibodies and also very important to test vitamin D, folate, ferritin and B12

Extremely common to have low vitamin levels, especially with Hashimoto's

Private tests are available. Thousands on here forced to do this as NHS often refuses to test FT3 or antibodies or vitamins

thyroiduk.org.uk/tuk/testin...

Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have money off offers.

All thyroid tests should ideally be done as early as possible in morning and fasting. When on Levothyroxine, don't take in the 24 hours prior to test, delay and take straight after. This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, GP will be unaware)

NHS guidelines saying standard starter dose is 50mcgs

beta.nhs.uk/medicines/levot...

riariariaria profile image
riariariaria in reply toSlowDragon

Thank you so much, this is helpful. I'm actually only on 25mcg. She only put me on that because I'm trying for a baby. It's pending review after the bloods I had yesterday. Last time (May) my TSH was slighly elevated and T4 was on the low side of normal. Thank you :)

SlowDragon profile image
SlowDragonAdministrator in reply toriariariaria

When trying to conceive TSH must be under 2.5

What were your TSH, FT4 and FT3 before starting on Levothyroxine

Obviously vitamin levels are extremely important too, especially B12 and folate for baby's neurological development. But vitamin D and ferritin important too

Essential to know if you have high thyroid antibodies as this is Hashimoto's and low levels of vitamins are more common

Pregnancy guidelines

thyroiduk.org.uk/tuk/about_...

gp-update.co.uk/files/docs/...

thyroiduk.org.uk/tuk/guidel...

Always take Levo on empty stomach and then nothing apart from water for at least an hour after. Many take early morning on waking, but it may be more convenient and possibly more effective taken at bedtime

verywell.com/should-i-take-...

Many people find Levothyroxine brands are not interchangeable. Once you find a brand that suits you, best to make sure to only get that one at each prescription. Watch out for brand change when dose is increased.

Many patients to do get on well with Teva brand, so best to start on different brand (unless lactose intolerant)

riariariaria profile image
riariariaria in reply toSlowDragon

My GP doesn't seem keen to go down the Hashimoto's route... I get the feeling she doesn't know too much about it.

My TSH was 4.36 in March then 4.67 in May

Free T4 was 17 in March then 13 in May - so there seemed to be a decline in 2 months.

FBCs have all been normal, but I've had slightly raised prolactin levels.

riariariaria profile image
riariariaria in reply toriariariaria

They've never tested my FT3!

SlowDragon profile image
SlowDragonAdministrator in reply toriariariaria

Raised prolactin is symptom of hypothyroidism

ncbi.nlm.nih.gov/pmc/articl...

Insist on antibodies and vitamin testing or test privately

riariariaria profile image
riariariaria in reply toSlowDragon

Thank you!

Angel_of_the_North profile image
Angel_of_the_North in reply toriariariaria

You don't want to be trying to get pregnant with TSH that high - too much risk of miscarriage and/or harm to the baby. Raised prolactin may be indicative of a pituitary problem meaning that you could have secondary hypothyroidism where TSH doesn't rise as high as you would expect given low free T4 and free t3. The baby needs your T4 to grow so it's important to find out if this is the case as you can't then dose by TSH. Don't expect a GP to understand that.

riariariaria profile image
riariariaria in reply toAngel_of_the_North

Yes we are of course holding off physically trying until my levels are better. Improving my levels is just another step on the (long) journey to hopefully conceiving. As I said earlier, I had my bloods done again on Tuesday so I'm hoping to see an improvement. I'll have a look into the pituitary stuff, thanks. I did have a brain MRI recently which was normal.

SlowDragon profile image
SlowDragonAdministrator in reply toriariariaria

High prolactin is usually primary hypothyroidism (Hashimoto's)

riariariaria profile image
riariariaria in reply toSlowDragon

Thank you, that's helpful information.

SilverAvocado profile image
SilverAvocado in reply toriariariaria

Oh dear, this TSH looks very high :( ideally it should be done close to 1 or below.

Unfortunately doctors know very little about dosing, you've got to double check everything, and may have to fight for a decent dose.

riariariaria profile image
riariariaria in reply toSilverAvocado

Thanks, that's so useful as my GP didn't bat an eyelid. She seems to think that because other people sometimes have higher levels mine don't really mean anything. I'm so symptomatic too!

riariariaria profile image
riariariaria

*UPDATE* my TSH is now 1.50 and my FT4 is back up to 17 so I'm really pleased. I guess that means I'll carry on with the 25mcg of levo. It will be another 6 weeks or more before the latest antibody results come back. Thanks for all the advice. :)

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