Similarities Between COVID-19 and Autoimmune Disease
February 6, 2021
Recent studies have demonstrated the distinct relationship between the infectious disease COVID-19 and autoimmune disease. The review titled “COVID-19 and Autoimmune Diseases” by Yu Liu, Amr Sawalha, and Qianjin Lu delves into the most recent research on the similarities, which include: dysregulated immune responses, the promise of immunomodulatory drugs to treat both conditions, the detection of certain autoantibodies, and the development of autoimmune diseases after SARS-CoV-2 infection. Investigating the relationship between these diseases is critical in preventing and treating COVID-19, as well as understanding the risks for individuals living with autoimmune disease.
In some individuals, SARS-CoV-2 infection triggers immune system dysregulation with the overproduction and release of pro-inflammatory cytokines and, in effect, damage to one or multiple organ systems. Cytokines are proteins that signal the immune system to fight infection, but in excess, they indicate the breakdown of self-tolerance. Similarly, autoimmune disease involves increased levels of pro-inflammatory cytokines, a loss of immune tolerance, and subsequent organ injury. As stated in the review, this parallel story between COVID-19 and autoimmune disease suggests that medications effective in treating autoimmune disease can have a similar impact on COVID-19. In fact, immunomodulatory drugs targeting excess cytokines (such as corticosteroids) are now being used to dampen the immune response in autoimmune disease as well as in severe COVID-19 in cases. While aiding in the treatment of the disease, the fact that SARS-CoV-2 triggers immune dysregulation may also “have important implications in the development of vaccine strategies against this virus,” state the authors of the review (1).
Another likeness between autoimmune diseases and COVID-19 is the release of autoantibodies, which are proteins that can target and attack the body’s own immune system and organs (2). Antinuclear antibodies (ANA) and antiphospholipid antibodies (APL) are examples of autoantibodies found in both autoimmune disease and COVID-19 patients. The results of one study “showed that 45% of the [COVID-19] patients were positive for at least one autoantibody and patients with positive autoantibodies tended to have a worse prognosis” (1).
We are also beginning to learn that a loss of immune tolerance from COVID-19 can lead to full-blown autoimmune diseases such as Guillain-Barre syndrome (GBS) and systemic lupus erythematosus (SLE) (1). While more of these post-infection autoimmunity cases are likely to be discovered, researchers are still unsure whether individuals with preexisting autoimmune diseases are at higher risk of SARS-CoV-2 infection in the first place. Studies around the world have returned with conflicting results, and thus no clear consensus on the issue.
As the scale is poised to tip in either direction, the authors of the review urge autoimmune disease patients to continue physical distancing, washing their hands, wearing masks, and sticking to their medical protocols – including any prescribed immunosuppressive drugs – to prevent flare-ups and avoid potential organ damage. While there are still unknowns about COVID-19 and its connection to autoimmune diseases, the evolving clues about their relationship bring us hope in understanding and characterizing COVID-19.