Despite their prevalence, thyroid disorders remain relatively misunderstood. Many people with thyroid disease don’t really make a connection between the health of their thyroid and the immune system. But when you have a thyroid autoimmune disease, you don’t have a problem with your thyroid, you have a problem with your immune system attacking the thyroid. So not only does your thyroid suffer, but so do many other systems in the body! Until the underlying cause is addressed - immune dysregulation, the thyroid treatment isn’t going to work very well, or for very long.
But how do the immune system cells actually start destroying the body they were designed to protect? It happens when some people don’t make enough T-suppressor cells, so the immune system’s attack goes on and on. Some people make too much interleukin 2(IL-2); then, an overabundance of natural killer and cytotoxic T-cells are deployed, putting healthy tissue at risk. There are also people who can make too much interleukin 4 (IL-4); then , an overabundance of B-cells looking for intruders to tag may accidentally mark healthy tissue, like the thyroid.
The Immune System and Your Underactive Thyroid
One of the common causes of an underactive thyroid gland (hypothyroidism) is autoimmune thyroiditis. With autoimmune thyroiditis, you make antibodies that attach to your own thyroid gland, which affect the gland’s function. The thyroid gland is then not able to make enough thyroxine and hypothyroidism gradually develops. Antibodies are a sign of some over-activity or misfiring of the immune system that needs to be quieted. Allowing it to persist will only lead to more autoimmunity and more tissue destruction.
When the lymphocytes enter the thyroid, they destroy the cells, tissue, and blood vessels within the gland. The process of destroying the thyroid gland is slow, and this is one reason why many people who have Hashimoto’s thyroiditis go many years without any noticeable symptoms. Even if your labs do not show elevated antibody levels, you could still have Hashimoto’s Disease. Undiagnosed Hashimoto’s disease is particularly common in patients with Chronic Fatigue Syndrome.
In extreme cases of tissue destruction, the immune cells can cause the thyroid to become enlarged and inflamed to the point that it produces a visible mass in the neck—a goiter.
There are many causes and theories about what triggers the immune system to make antibodies against the thyroid. Genetics can definitely be a factor, as are nutritional deficiencies like low iodine, selenium, zinc, and iron, hormonal irregularities, a wide range of chronic infections, environmental toxins and leaky gut. Chronic infections cause an imbalance in the immune system that makes it less able to fight attacking organisms, but more likely to attack the body.
The Immune System and Your Overactive Thyroid
Graves’ disease is an autoimmune disease that can cause overactivity of the thyroid — a condition known as hyperthyroidism. Normally, thyroid function is regulated by the pituitary gland, a tiny gland responsible for secreting TSH, which signals the thyroid to produce thyroid hormones T3 and T4.
In Graves’ disease the body produces an antibody known as thyrotropin receptor antibody (TRAb) against the thyroid receptors called TSI (Thyroid Stimulating Immunoglobulin). When this auto-antibody binds to the thyroid receptors, the thyroid gland is stimulating to release more T4 hormone than needed.
Researchers are still investigating all the factors which trigger this autoimmune response. Hyperthyroidism can result from toxic nodules, certain medications and supplements, temporary viral infections of the thyroid, and due to genetics, among other known and unknown causes.
As with other autoimmune conditions, Graves’ disease is more likely to affect women than men. Graves’ is most common in women older than 20 years old. However, people of any age—including men—can have Graves’ disease.
How Can You Find Out Your Immune System Is Attacking Your Thyroid?
Physicians generally order a very limited thyroid blood panel excluding antibodies-mainly because they believe autoimmune diseases are untreatable. But this is false. Many people recover from autoimmune diseases.
In addition to the standard thyroid function tests such as the TSH, Free T4, and Free T3, your doctor should also check for increased levels of specific antibodies to thyroid proteins. The “red flag” antibodies to check are thyroid peroxidase (TPO) and antithyroglobulin. Antibodies are proteins used by the immune system to detect and respond to threats. Thus, if you have a thyroid-related autoimmune disorder, blood tests could potentially indicate increased anti-thyroid antibodies.