Understanding The Different Types of Thyroid Antibodies
Published August 28 2017
There are different types of thyroid antibodies that are present in autoimmune thyroid conditions. Some people with Graves’ Disease and Hashimoto’s Thyroiditis test positive for only one type of thyroid antibody, while others will test positive for multiple antibodies. In this article I will discuss why people develop these thyroid antibodies. I will then discuss some of the different types of antibodies.
But it probably makes sense to first discuss what an antibody is. An antibody is a Y-shaped protein that is part of an immune system response to something called an antigen. An antigen is a foreign substance (i.e. pathogenic bacteria, food proteins, chemicals) that causes an immune response. These antibodies are secreted by B cells of the immune system, and they essentially serve as a form of protection.
So for example, if someone has a bacterial infection, the body will produce antibodies that specifically bind to the bacteria, and these antibodies can also cause the immune system to respond in other ways to destroy the bacteria. Similarly, if someone has a sensitivity to a certain food then they will produce antibodies against the food proteins. With autoimmunity, the antibodies bind to the body’s own tissues. These are the antibodies that are measured when doing a blood test, and of course I’ll be talking about these during this article.
Why Do Some People Develop Thyroid Antibodies?
There are both environmental and genetic factors that can cause people to develop thyroid antibodies. However, not everyone with a genetic predisposition and/or environmental exposure end up developing an autoimmune thyroid condition. So for example, infections such as H. Pylori and Blastocystis Hominis can be autoimmune triggers. If someone has a genetic predisposition for Graves’ Disease and gets exposed to H. Pylori, this doesn’t mean that they will develop this condition. Similarly, someone with the genetic markers for Hashimoto’s Thyroiditis won’t always develop this condition upon being exposed to Blastocystis Hominis.
Recently I wrote a blog post on the triad of autoimmunity, and in this post I discussed three factors which are required for the development of an autoimmune condition. Earlier I mentioned that a genetic predisposition and an environmental trigger are required, and the third component is an increase in intestinal permeability, which is also known as a leaky gut. Having these three components will set the stage for the development of an autoimmune condition. A decrease in regulatory T cells and a loss of immune tolerance are also factors, and these are associated with a leaky gut.
Based on what I just said, if someone with a genetic predisposition for Hashimoto’s Thyroiditis has a leaky gut, this can lead to a decrease in regulatory T cells and a loss of immune tolerance. Then one day this person is exposed to an environmental trigger, which in turn initiates the autoimmune process. This person will typically form thyroid peroxidase and/or thyroglobulin antibodies, although it can take years for this process to lead to symptoms and affect the TSH and thyroid hormone levels on a blood test. In other words, the person with Hashimoto’s Thyroiditis will develop thyroid antibodies well before they present with symptoms and have an abnormal thyroid panel.
With Graves’ Disease the antibodies also will develop first, although it usually affects the thyroid panel much quicker. In other words, whereas it will usually take many years for someone with the antibodies for Hashimoto’s to develop hypothyroidism, those with the antibodies for Graves’ Disease will usually develop hyperthyroidism relatively quickly.
The Rational Behind Testing The Thyroid Antibodies First
If you have an autoimmune thyroid condition and if you have children, since genetics is a factor then you might think it’s a good idea to have your children do an updated thyroid panel on annual basis to make sure they don’t develop an autoimmune thyroid condition. But what we really should be doing is screening for the presence of thyroid antibodies. This is also true for other autoimmune conditions, and this is known as predictive autoimmunity. One can argue that children are less likely to develop autoimmunity than adults, which is true, although more and more children and teenagers are developing autoimmune conditions than ever before.
Based on what I just said, for those who have Graves’ Disease or Hashimoto’s Thyroiditis, it probably sounds like a good idea to screen your children for the presence of thyroid antibodies every now and then. Just keep in mind that you might have to obtain such testing on your own and pay out of pocket. And the reasons for this are because 1) most medical doctors won’t recommend to test the thyroid antibodies unless if they first see abnormalities in the thyroid panel, and 2) most health insurance companies won’t pay for testing of thyroid antibodies unless if they consider it to be medically necessary. And once again, if someone has a normal thyroid panel then they most likely won’t consider a test for thyroid antibodies to be medically necessary.
Another problem is that a “normal” thyroid panel doesn’t necessarily mean an “optimal” panel. In other words, the TSH and thyroid hormone levels might be within the lab reference range, but not within an “optimal” reference range. So if someone had a TSH of 4.0, less than optimal thyroid hormone levels, and was experiencing hypothyroid symptoms, if all of the values fell within the lab reference range then many medical doctors still wouldn’t order the thyroid antibodies.
The good news is that many people can order thyroid antibodies testing on their own. For example, in the United States, many states will allow a patient to order their own labs through an online testing service, and there are also a number of walk-in labs where you can get almost any blood test you want without a doctor’s order. Unfortunately there are a few states that don’t allow this, and if you live in a different country then you may or may not have these options available.
What Are The Different Types of Thyroid Antibodies?
There are four main types of thyroid antibodies: 1) thyroid peroxidase antibodies, 2) thyroglobulin antibodies, 3) thyroid stimulating immunoglobulins, and 4) thyrotropin-blocking antibodies. Since these antibodies are targeted against the body’s own proteins, they are often referred to as autoantibodies. People with Hashimoto’s will often have thyroid peroxidase and/or thyroglobulin antibodies. People with Graves’ Disease will usually have thyroid stimulating immunoglobulins, which is a type of TSH receptor antibody. It’s less common for a person to have thyrotropin-blocking antibodies.
Let’s take a closer look at the four main types of thyroid autoantibodies:
1. Thyroid peroxidase antibodies: Thyroid peroxidase (TPO) is an enzyme that is vital in the production of thyroid hormone. Antibodies against TPO are called anti-TPO antibodies. On a lab report you might see it listed as “thyroid peroxidase” or “TPO” antibodies. They are the most common type of thyroid antibody. In addition, they are present in over 90 percent of people with Graves’ disease and Hashimoto’s Thyroiditis (1). They are also associated with the destruction of thyroid follicles, along with thyroglobulin antibodies (2). This is why people who have these thyroid autoantibodies are likely to become hypothyroid if the autoimmune response isn’t addressed.
2. Thyroglobulin antibodies: Thyroglobulin is a glycoprotein that is secreted by thyroid follicular cells and stored as a colloid substance in the thyroid follicles (1). Approximately half of the protein content in the thyroid is composed of thyroglobulin. These antibodies are more commonly associated with Hashimoto’s Thyroiditis, although one source showed that 30 percent of Graves’ Disease patients will test positive for these as well (1). I must admit that I commonly see these antibodies present in my Graves’ Disease patients, although 30 percent does seem to be somewhat high. On a lab report you will usually see these described as “thyroglobulin antibodies”, although occasionally they will be listed as “TG” antibodies.
Please be aware that many labs will also offer a separate test for “thyroglobulin”, which is different than the “thyroglobulin antibodies”. I’ve seen a few cases where the doctor accidentally ordered “thyroglobulin” and it was negative, and the patient thought they didn’t have an autoimmune component, only to later have the thyroglobulin antibodies tested and realize that these were elevated. If someone has an elevated thyroglobulin (not thyroglobulin antibodies) then this can be an indication of an iodine deficiency (3), or in some cases thyroid cancer (4).
3. Thyroid stimulating immunoglobulins: Thyroid-stimulating hormone receptor (TSHR) is mainly found on the surface of thyroid follicular cells (5), although they are also found on other cells as well, such as fibroblasts (6). Thyroid stimulating immunoglobulins or antibodies (TSAbs) bind to this receptor and stimulate the overproduction of thyroid hormone. Essentially TSAb mimics the effects of thyroid-stimulating hormone (TSH). On a lab report you probably will see it labeled as “thyroid stimulating immunoglobulins”, although you might also see TSI or TSAbs.
Some labs don’t test for thyroid stimulating immunoglobulins but instead will test for thytrophin receptor antibodies, which on a lab report might be abbreviated as TRAB. Thyroid stimulating immunoglobulins are a type of thytrophin receptor antibody. If someone has hyperthyroidism along with elevated thytrophin receptor antibodies then this is a pretty good indication that the person has Graves’ Disease. Thyroid stimulating immunoglobulins are the most common type of thytrophin receptor antibody. However, it’s important to know that there are other types of these antibodies, including thytrophin-blocking antibodies, which I’m about to discuss.
4. Thyrotropin-blocking antibodies: A thyrotropin-blocking antibody is another type of thytrophin receptor antibody. Unlike thyroid stimulating antibodies, the thryotopin-blocking antibody (TBAb) blocks the TSH receptor to prevent TSH from binding. This action essentially induces hypothyroidism as TSH isn’t able to produce its intended effects since thyroid hormone cannot be stimulated to be released.
The Significance Of Negative Thyroid Antibodies
Most people with Graves’ Disease and Hashimoto’s Thyroiditis will test positive for thyroid antibodies on a blood test. However, this isn’t always the case, which can make it very challenging to know that someone has an autoimmune thyroid condition. Sometimes it’s just a matter of doing another test. For example, I’ve seen patients test negative for thyroid antibodies on a blood test, but then a couple of months later have them test for the same antibodies and see them come out positive.
But this isn’t always the case. Since these antibodies are mainly of the immunoglobulin G (IgG) class (1), having depressed IgG levels can potentially result in a false negative result. While testing the serum IgG levels might be a good idea, having normal levels won’t always rule out a false negative result. If Hashimoto’s Thyroiditis is suspected but the thyroid antibodies are negative then a thyroid ultrasound can reveal if the person has this condition. If Graves’ Disease is suspected but the person has negative thyroid antibodies on a blood test, an ultrasound might also provide some answers, although some endocrinologists recommend a radioactive iodine uptake test to determine if someone has Graves’ Disease.
How Can You Lower Your Thyroid Antibody Levels?
Unfortunately most endocrinologists, as well as other medical doctors, don’t pay much attention to the thyroid antibodies. Sure, they might test for them to confirm if someone has Graves’ Disease or Hashimoto’s Thyroiditis, but most won’t give any recommendations to lower them. In fact, since most medical doctors don’t do anything for the health of the immune system, many will refuse to retest the thyroid antibodies, as they don’t expect them to decrease. So with Hashimoto’s Thyroiditis, most medical doctors will simply prescribe thyroid hormone medication and won’t do anything else, while those people with Graves’ Disease will either be told to take antithyroid medication for a prolonged period of time, or many times they will be pressured into receiving radioactive iodine or thyroid surgery.
Of course in order to lower the thyroid antibodies it is necessary to improve the health of the person’s immune system. This admittedly is easier said than done, but in order to accomplish this you essentially need to 1) detect and remove the environmental trigger, 2) heal the gut, and 3) correct other imbalances.
What Should You Do If Your Antibodies Remain High After Treatment?
What approach should you take if you follow a natural treatment protocol and still have elevated thyroid antibodies? This is a common problem, as I have worked with patients who prior to consulting with me have seen other natural healthcare professionals in order to try getting into remission, only to be frustrated when their antibodies remain elevated. I discuss this issue at length in a previous blog post entitled, “Why Are My Thyroid Antibodies Still High?” As I discussed in the blog post, the reason why someone’s antibody levels still remain high after natural treatments is usually caused by one or more of the following factors:
1. The environmental/autoimmune trigger hasn’t been removed. This relates to the triad of autoimmunity, as you need to remove the environmental trigger. For example, if gluten is triggering the autoimmune response, you of course need to completely eliminate it from your diet. And it probably is a good idea to avoid certain products that might contain gluten, such as cosmetics. It’s important to understand that people with Graves’ Disease and Hashimoto’s Thyroiditis can have multiple triggers. As a result, if you initially did some testing and found a potential autoimmune trigger and then removed it, yet still have elevated thyroid antibodies, then this can mean that there are one or more additional triggers that haven’t yet been detected. In this situation additional testing may be required.
2. The autoimmune response hasn’t been suppressed. Although removing the environmental trigger may result in the autoimmune response being suppressed, this isn’t always the case. Autoimmunity involves high levels of pro-inflammatory cytokines, and even once the autoimmune trigger has been removed you very well might need to do things to suppress the inflammatory component. Eating an anti-inflammatory diet is of course important, but taking nutrients and herbs that reduce pro-inflammatory cytokines can also be beneficial. Examples include omega-3 fatty acids, vitamin D, turmeric, and resveratrol.
3. The gut hasn’t been healed. This is another component of the triad of autoimmunity. Sometimes removing the environmental trigger will also heal a leaky gut, although this isn’t always the case. According to the 5-R protocol you want to first remove the factor which caused the leaky gut in the first place before doing things to repair the gut. This might sound like common sense, but many people will take gut healing agents such as L-glutamine, yet won’t do anything to remove the “leaky gut trigger”. For example, if gluten is your leaky gut trigger, and if you do things for gut healing such as take L-glutamine and drink bone broth, but continue to be exposed to gluten, then you won’t heal the gut.
4. Other compromised areas have not been addressed. If someone has removed the environmental trigger, suppressed the inflammation, and has healed their gut, then this should be sufficient to normalize their thyroid antibodies. However, if you still have elevated thyroid antibodies after accomplishing this then you should look into other imbalances. For example, if someone has weakened adrenals then this can be a factor. Of course one can argue that this would fall into the autoimmune triggers category, as stress is a trigger, which in turn will affect the adrenals. However, even if someone has reduced their stress levels and/or improved their stress handling skills, they probably will need to do other things to improve the health of their adrenals.
The Importance of Patient Compliance In Lowering Thyroid Antibodies
One thing I didn’t cover in the “Why Are My Antibodies Still High” blog post is the importance of patient compliance. Of course this should be obvious, but the patient needs to make the necessary dietary and lifestyle changes in order to get optimal results. It admittedly can be a big challenge to follow a strict diet, improve your stress handling skills, etc. But following the recommendations given by the natural healthcare professional you’re working with is essential in order for you to receive optimal results.
In summary, people with Graves’ Disease and Hashimoto’s Thyroiditis have thyroid antibodies, which bind to the body’s own tissues. The triad of autoimmunity explains why some people develop elevated thyroid antibodies, and the three components include 1) genetics, 2) an environmental trigger, and 3) a leaky gut. Thyroid antibodies can be measured in the blood, although false negatives are possible. The four types of thyroid antibodies I discussed in this article include thyroid peroxidase antibodies, thyroglobulin antibodies, thyroid stimulating immunoglobulins, and thytrophin-blocking antibodies. If someone has high antibodies after following a natural treatment protocol it usually is because the autoimmune trigger hasn’t been removed, the leaky gut hasn’t been healed, and/or the autoimmune response hasn’t been suppressed.