Significance of Anti-TPO as an Early Predictive Marker in Thyroid Disease

[helvella]

Many people have asked what the significance of Thyroid Peroxidase antibodies is in those who currently have no obvious thyroid hormone issues.

This paper looks at that and comes up with some answers.

Considering that few get tested for TPOab before diagnosis, and many don't even after diagnosis of hyper- or hypothyroidism, this paper probably has little direct relevance. But it might serve to encourage testing and, if elevated TPOab are found, further encourage repeated testing.

Autoimmune Dis. 2019; 2019: 1684074.

Published online 2019 Jul 28. doi: 10.1155/2019/1684074

PMCID: PMC6699358

Significance of Anti-TPO as an Early Predictive Marker in Thyroid Disease

Thushani Siriwardhane, 1 Karthik Krishna, 2 Vinodh Ranganathan, 2 Vasanth Jayaraman, 2 Tianhao Wang, 2 Kang Bei, 2 Sarah Ashman, 1 Karenah Rajasekaran, 2 John J. Rajasekaran, 2 and Hari Krishnamurthy

Abstract

Even though most thyroid subjects are undiagnosed due to nonspecific symptoms, universal screening for thyroid disease is not recommended for the general population. In this study, our motive is to showcase the early appearance of thyroid autoantibody, anti-TPO, prior to the onset of thyroid hormone disruption; hence the addition of anti-TPO in conjunction with traditional thyroid markers TSH and FT4 would aid to reduce the long-term morbidity and associated health concerns. Here, a total of 4581 subjects were tested multiple times for TSH, FT4, anti-TPO, and anti-Tg and followed up for 2 years. We streamlined our subjects into two groups, A1 (euthyroid at first visit, but converted to subclinical/overt hypothyroidism in follow-up visits) and A2 (euthyroid at first visit, but converted to hyperthyroidism in follow-up visits). According to our results, 73% of hypothyroid subjects (from group A1) and 68.6% of hyperthyroid subjects (from group A2) had anti-TPO 252 (±33) and 277 (±151) days prior to the onset of the thyroid dysfunction, respectively. Both subclinical/overt hypothyroidism and hyperthyroidism showed a significantly higher percentage of subjects who had anti-TPO prior to the onset of thyroid dysfunction compared to the combined control group. However, there was no significant difference in the subjects who had anti-Tg earlier than the control group. Further assessment showed that only anti-TPO could be used as a standalone marker but not anti-Tg. Our results showcase that anti-TPO appear prior to the onset of thyroid hormone dysfunction; hence testing anti-TPO in conjunction with TSH would greatly aid to identify potentially risk individuals and prevent long-term morbidity.

Full paper available here:

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

Do be aware that the paper includes this:

Conflicts of Interest

Siriwardhane and Ashman are employees of Vibrant America LLC. Krishna, Ranganathan, Jayaraman, Wang, Bei, Rajasekaran (K), Rajasekaran (J), and Krishnamurthy are employees of Vibrant Sciences LLC.

[LindaC]

Thank you helvella - your posts are most interesting - much appreciated.

[NWA6]

So are they saying ANY existence of TpoAb shows sigh of Hashimotos (or heading that way)or is it still that it needs to be overrange?

So I didn’t read the paper! Science stuff needs diluting for me 😬 (grade C at GCSE just doesn’t seem to cut it! Lol)

[helvella Administrator Thyroid UK in reply to NWA6]

They are basically talking about over-range, as I understand.

The extreme lowest levels are uncertain anyway. They could be figments of the process or real but very low levels.

[NWA6 in reply to helvella]

Yeah thought so but why else do we have TPOAb’s? I’m sure someone has said something before but just curious now as in why do people have TPoabs (below range) and also could someone have over range but not be Hypo or are they just not Hypo YET?

[helvella Administrator Thyroid UK in reply to NWA6]

Because Thyroid Peroxidase, an enzyme that should ONLY be in the follicles of the thyroid, is actually leaking into the bloodstream. And our immune systems are trying to clear it out.

Not hypo YET. Or, possibly, not hypo (nor hyper) EVER. Just more likely if found.

[helvella Administrator Thyroid UK in reply to NWA6]

Do consider that every so often a thyroid follicle could get spilled in an otherwise perfectly healthy person. Suggested possibilities include a car seat belt or, possibly, just one of those things without any obvious cause.

And any test has a threshold below which it is unreliable. A car speedometer below 10 mph is potentially very inaccurate. Some cars, therefore, don't register anyhing between 0 and 10. Others do, but it has to be taken with a pinch of salt. The very bottom of the TPOab tests is often not reported as a number, just says <4 (or whatever number). The "true" value could be anywhere between 0 and 4 but without any certainty where it lies.

[NWA6 in reply to helvella]

Yeah I’m just keeping an eye on my daughters TPO which is why I’m interested (currently 18 (<34)), ‘normal’ TSH. Low T4 but FT4 57% and FT3 54%

[SilverAvocado in reply to NWA6]

Just for interest I looked up my own TPO results. I have no thyroid and as far as I know have never had Hashimotos.

Mine has varied between about 8.5 and 9.5. It's not that low considering the range is <34!

[lucylocks in reply to SilverAvocado]

Mine are 32 so very near top of range and Thyroglobulin Antibodies 115 <115 so I don't know if I have hashi's or not.

[SilverAvocado in reply to lucylocks]

Unfortunately it's quite difficult to find out what levels a person with a healthy thyroid and no Hashimoto's would expect to have

If you spontaneously developed hypothyroidism at some point (even in childhood, but particularly if it was during pregnancy, menopause, or another well known trigger like a car accident or giving up smoking), then you almost certainly do have Hashimoto's. Probably the most likely after that would be Central hypothyroid, which you could see in blood tests while undermedicated. I don't know the percentage on each category, but I believe Hashimoto's is well over 90%.

Unfortunately it's possible to have Hashimoto's but never get a positive anti body test.

[lucylocks in reply to SilverAvocado]

Hi

I was diagnosed hypo eight years ago. I was told I did not have the autoimmune type by the Doctor, he said my level was 58 top of the range 70.

When checking my levels with Medichecks, they do vary, but the highest had been as I mentioned.

It is all a bit confusing.

[Marz]

I have just waved off my daughter who tested here in Crete with positive Anti-TPO antibodies 7 years ago. UK Tests proved otherwise. She is now under the care of a renowned Nutritionist. My observations are clear-cut but of course I am simply a mother of a 52 year old lady - and hell what do I know ? It is breaking my heart 💘

[NWA6 in reply to Marz]

Oh Marz 😢

[vocalEK]

I'd love to see this research repeated, adding in measures of free T3. Wonder how it all correlates.