In this educational monologue, Dr. A answers a viewer’s question about thyroid antibody testing. He begins by defining antibodies as immune proteins and explains that thyroid antibodies are auto‑antibodies that mistakenly target components of the thyroid gland. Dr. A outlines the two ends of the autoimmune thyroid disease spectrum: Graves’ disease (hyperthyroidism) driven by thyroid‑stimulating hormone receptor antibodies (TSI) that mimic TSH and over‑activate the gland, and Hashimoto’s disease (hypothyroidism) driven by thyroid peroxidase (TPO) and antithyroglobulin antibodies that impair hormone synthesis. He describes the biochemical role of TPO and thyroglobulin in iodine incorporation and hormone production, showing how auto‑antibodies disrupt these steps. The video then details the three main antibody tests—TSI (or TSH‑receptor antibodies), TPO, and antithyroglobulin—explaining when each is ordered, why clinicians may order all three in mixed or early‑stage cases, and how the results help interpret abnormal thyroid function tests (TSH, free T3, free T4) and guide treatment. Dr. A emphasizes that antibody testing is useful when symptoms are present despite normal hormone levels, when hyper‑ or hypothyroid signs are evident, or when an autoimmune component is suspected. The talk concludes with a reminder that both Graves’ and Hashimoto’s are autoimmune conditions, each affecting thyroid hormone output in opposite directions, and encourages viewers to engage with the channel.
Chapters
Hey, it's Dr. A answering a question today about thyroid antibodies. The person says that their doctor said, in addition to their TSH and their T3 and their T4, they're supposed to have some thyroid antibodies tested. And first, what does that mean? What are they? What do they mean if they're positive? And why do I need them tested? So it's a really great question. By the way, thank you everyone for your comments and questions. Love them. So thyroid antibodies. First thing, an antibody is something that your immune system makes, and we've got other videos on. You can look at the T and B cell antibody videos, stuff like that. But basically, it's part of your immune system that makes an immune protein. So you've heard of immunoglobulins or Ig's. These are immune proteins that have receptor site that locks onto something. Now, in the case of the thyroid, there's 3 different major targets of thyroid antibodies. So the first thing that you have to ask yourself is, well, if we're making antibodies, usually isn't it to something bad, like, you know, like a bug, bacteria, or virus, or something like that? The answer is yes. But when you have an autoantibody made, meaning an antibody made against you, You now have an autoimmune trigger which can create an autoimmune condition. Now, we'll talk about in a separate YouTube about what autoimmunity is and the mechanics of it and all of that, but basically what happens is there are parts of your thyroid where the immune system gets confused and it decides to make antibodies against you and specifically against parts of your thyroid. Now, to understand this a little bit more deeply, we'll just briefly talk about kind of the 2 ends of the spectrum when it comes to thyroid antibody-triggered diseases. So on one end of the spectrum, there's Graves' disease, and that is a hyper, a high thyroid condition, too much thyroid. On the other end, normally there is Hashimoto's disease or Hashimoto's syndrome, where you have not enough thyroid, low thyroid, hypothyroid. So in the case of Graves', where you have this high activity of your thyroid, what happens is your immune system sends confusing messages through antibody production to your thyroid that says produce more thyroid. Now normally what happens is that your brain will shut your thyroid down if it's overproducing. But in this case, your brain is not in charge anymore. It is the antibodies that trigger your Graves' disease. So too much thyroid causes hyperthyroid, high thyroid, and that increases your metabolism and your cell turnover. So you think, well, what's wrong with a little bit of extra metabolism? Well, that's mediated through your mitochondria, and you have the most mitochondrial density in your body in your heart. And so you can actually have heart irregularities. You can get high heart rates, arrhythmias, other problems. In fact, you can die with Graves' disease from cardiovascular complications. I have had patients over the years who enjoyed the fact that they were losing weight and they weren't trying, and they had an early onset of a Graves' disease picture. But what was going on is their metabolism was just chewing up more energy and more energy every day. They weren't getting a lot of cardiac effects other than a high heart rate, so they They didn't want to tell me, and they waited till they lost 15 or 20 or 25 pounds. Now, that might seem fun, you know, with respect to the weight loss, but with respect to your cardiovascular activity, you don't want that much thyroid around, so you do have to do something about it. Now, the thyroid stimulating hormone receptor antibodies, often called the TSI, Or there's a group of them, there's 2 major ones. Basically what your immune system is doing is kind of taking the place of the TSH, the thyroid stimulating hormone, only not doing a very efficient job of it. And it's attacking in 1 or 2 different places on the thyroid to stimulate your thyroid to overproduce thyroid hormone without feedback from the brain. So your T3 and your T4 will go way up and these antibodies will be elevated. So if you have symptoms and signs of Graves' disease, among other things, things your doctor might do, that antibody set may be one, the thyroid stimulating hormone receptor antibody set. That would be one definitely they would order. They'd also order to see what your, you know, T3 and T4 are doing, see how overproducing your gland is, et cetera. Now, if we go to the other end of the spectrum, there's 2 primary Hashimoto's antibodies. And what you want to think of is Hashimoto's generally winds up with low thyroid, hypothyroid, and so you have slow sluggish metabolism, you have sluggish everything, you, you tend to be more sleepy, you gain weight easily, your hair and your nails become brittle because they're rapidly dividing tissues and you need thyroid for that. You can get some brain fog, you can have all sorts of things go on with Hashimoto's or low thyroid. Hashimoto's is the, or one of the most prevalent autoimmune diseases in humans. So in that case, normally the thyroid stimulating receptor antibodies are not high, but the other 2 are, one or the other or both. So TPO, the thyroid peroxidase antibody, also known as the antimicrosomal antibody, but modern times we just call it the TPO. And then the other is the thyroglobulin antibody, the antithyroglobulin antibody. Now, why would these, instead of like the thyroid stimulating one in Graves', which make you have hyper— overproduction of thyroid, why would these antibodies, the TPO and the antithyroglobulin, shut your thyroid down, make it really slow? Well, they do that because in your thyroid, to make thyroid hormone, you have this synthetic process that goes on where you carry iodine in And then you have a tyrosine molecule, the amino structure tyrosine. So it's sitting there like this, and then you have this little machinery system that peroxidases the iodine and adds one iodine at a time until you have 4, usually maybe 3, so T3 or T4, and then it's sent out into the bloodstream. Now if I attack the peroxidase system with autoantibodies. We call that thyroid peroxidase antibodies, and those will go up. So obviously, if I slow the peroxidation of iodine down, am I going to put it onto the tyrosine? That's going to slow it down. I also can attach and attack the thyroglobulin system. So I've got my little tyrosine sitting out here getting iodine on them, but they're in a synthetic sort of a docking station on this thyroglobulin, and proteins, basically a large protein structure, and they're sitting there. So if I attack the large protein structure, I'm going to mess with this as well. Now, most of the time, doctors will often just check the TPO antibody because in most Hashimoto's, that's what's the highest. But what I found in people who either have labs that are borderline or there's other things going on, we will just check both of those, the TPO and the antithyropothyron antibody, And yes, it costs a little bit more at the lab end, not really a lot because these are generally fairly inexpensive tests, but what I find is I catch a lot more early cases of thyroid autoimmunity if I check both. Now, why would your doctor maybe check all of them? Well, Hashimoto's, usually it's TPO, antithyroglobulin, or both. In Graves', it's usually the thyroid stimulating immunoglobulin. globulins, or the thyroid stimulating hormone receptor antibodies. But in Graves', sometimes you'll have a mixture of those. Usually in Hashimoto's, you don't get the TSH receptor antibodies on, you just get the TPO and the T-thyroglobulin, but you can have both. And so sometimes to get the full picture, they might order all 3, especially if you have some mixture of symptoms and they want to see which direction you're going. Because one thing that can happen, not to everybody, but what can happen sometimes early on in autoimmune thyroiditis is you might be going towards Hashimoto's disease and low thyroid, but you might have a little uptick where you have some hyperthyroid symptoms and then they sort of drop off. So if your doctor catches you in that early stage, they may actually run all 3 or the 3, there's really a couple of Mixed in with the third one. So those are your common tests. And so to answer the question, why would your doctor order thyroid antibodies? Sometimes they'll do it if your regular labs, your TSH and your free T4 and free T3, don't look too bad, but you have symptoms. Sometimes they'll do it just right away if you have symptoms of Graves' disease, the hyperthyroid symptoms. And sometimes they'll do it if, you know, maybe it looks like you could go on thyroid because you have a little bit of low thyroid, but they just want to see— do you also have an autoimmune component as well? And so it's important to remember that both of these are autoimmune phenomena, meaning that your immune system is making these antibodies and they're going in, in the case of low thyroid on the Hashimoto's end, they are attacking the synthetic part of your thyroid where you're making your thyroid hormones, so that's going to keep it low, and on the Graves' disease, the hyper, high thyroid end, they are actually attacking the receptor systems that stimulate your thyroid to make. So instead of blocking it, they actually are hyperproduction-oriented. All right, well, I'm Dr. A. It's been my pleasure speaking with you. Please comment, like, subscribe, notifications, all that good stuff. Really appreciate everything. Appreciate all the new subscribers, and keep telling your friends, and I will keep answering questions. Thank you very much.
