We have known since the early 1970s that infections can trigger autoimmune diseases and now we have an interesting hypothesis on the potential triggering of Hashimoto’s disease by COVID-19 infection.
A recent case study out of Singapore published in the Singapore Medical Journal entitled, “COVID-19 complicated by Hashimoto’s thyroiditis” presents an individual who developed Hashimoto’s thyroiditis after contracting COVID-19.
COVID-19 can cause a hyperinflammatory state in the body which is a potential recipe for developing autoimmune disease. The authors begin by pointing out the most current literature on COVID-19 connections to the autoimmune diseases antiphospholipid syndrome, autoimmune thrombocytopenia, autoimmune hemolytic anemia, and Guillain-Barre syndrome.
This patient was a 45-year-old Chinese man who developed a non-productive cough and rhinorrhea for one day after exposure to COVID-19 in his dormitory. On the second day of his symptoms he was diagnosed with confirmed COVID-19 infection.
His symptoms went away after 7 days, but he reported new onset of severe generalized fatigue and muscle weakness. Before these symptoms happened, he was in good health, not taking any medications or supplements, working productively, and no history of smoking. He had no family history of autoimmune disease.
His physical examination was unremarkable and his thyroid was normal without goitre. However, his TSH level was high at 6.49 and his free T4 was low at 9.19 which is a classic presentation for hypothyroidism. His thyroid peroxidase antibody was extremely high at >2,000 confirming Hashimoto’s disease. His inflammatory markers were normal as well as electrolytes and other metabolic tests. Chest x-ray was completely normal.
He was prescribed 25mcg of levothyroxine once a day and five weeks later he reported increased energy, and he had started running again. His TSH was 6.59 and free T4 was 10.91 so those markers did not improve despite the medication and his energy improving.
The authors state that the onset of his symptoms from the time he first developed COVID-19 to the time he developed Hashimoto’s disease was similar to the onset of the other 4 autoimmune disease connections noted above in previous studies.
The authors conclude that the hyperinflammatory state triggered by COVID-19 also known as a “cytokine storm” can predispose patients to developing autoimmune diseases such as Hashimoto’s thyroiditis.
Dr. Hedberg’s Comments
Some patients will develop Hashimoto’s disease after getting the flu or other infections such as Epstein-Barr virus, H. pylori, Yersinia enterocolitica, Blastocystis hominis, Parvovirus-B19, Hepatitis C, and Herpes 6 to name some of the most common triggers.
Infections can cause abnormal shifts in the immune system thus triggering autoimmunity in predisposed individuals. Normally, it takes three important factors to trigger autoimmune disease:
1. A genetic predisposition.
2. A gut problem such as leaky gut or intestinal dysbiosis.
3. A triggering event such as infection, physical or emotional trauma, giving birth, mold exposure, medications, radiation exposure, excessive iodine exposure, or toxin exposure such as mercury.
What is interesting about this case is that he did not have a genetic predispostion at least not that we knew of or was stated in this paper. We also don’t know if he had any gut problems.
The cytokine storm caused by COVID-19 can be quite intense compared to other infections so perhaps any predisposing factors were overriden by the storm. This is just speculation on my part but with only a single study subject and not more data about this individual, there isn’t much more to go on other than what we know about how the immune system responds to infections and how autoimmune diseases are triggered.
Additional speculation on my part would be that if you have an autoimmune disease like Hashimoto’s disease, contracting COVID-19 could cause a major flare up of your symptoms.
This is all the more reason to wear a mask and practice all the recommended guidelines for minimizing exposure to this virus. Remember that if you have one autoimmune disease you have a greater chance of developing a second autoimmune disease. A COVID-19 infection may be a trigger for another autoimmune dsease which would be a tragedy for someone already dealing with one autoimmune disease.
We are still learning more and more each day about COVID-19 and based on the research cited in this paper we may be seeing increased rates of autoimmune disease or exacerbation of existing autoimmune disease symptoms due to this pandemic.