Viruses are known to precipitate autoimmune diseases, but the link between COVID-19 and autoimmune conditions requires additional research.
Nearly 3 years into the global COVID-19 pandemic, there are still some unknowns about the disease. Long COVID, for example, is still not fully understood, and neither are the long-term effects of COVID-19 infection. One area of particular interest for researchers is that of new-onset autoimmune diseases—the rates of which are currently on the rise, according to a study published in eClinical Medicine.1
According to researchers, there are “a growing number of case reports of various autoimmune diseases occurring after COVID-19,” but investigators currently lack the large-scale population data required to support the association.1 But, said Yehuda Shoenfeld, MD, “there are several publications that indicate emergence of autoimmune diseases from COVID-19.” Shoenfeld is a professor of medicine at Tel Aviv University’s Zabludowicz Center for Autoimmune Diseases. “There’s another virus, Epstein-Barr virus, responsible for at least 23 autoimmune diseases, and we believe there will be a significant increase in incidence of different autoimmune diseases from COVID-19,” he explained.
The challenge is that COVID-19 is still new and autoimmune diseases can sit dormant for months or years; there’s no way to know whether the SARSCoV-2 virus will follow a similar path. “We don’t know when it will emerge,” Shoenfeld said. “We are planning a large population study to see what has happened [1.5 years] after people got COVID-19.”
Shoenfeld collaborated on a new book, scheduled for release this year, that includes findings he has collected over the past year and looks at which individuals may be at risk for developing autoimmune diseases and measurements based on studies to examine trends. Already, he has seen a number of patients who received a diagnosis of COVID-19 and also a diagnosis of an autoimmune disease. Based on those data, he and his research team have assumed that there is a link.
“As a matter of fact, from the onset of the SARS-CoV-2 pandemic in 2020, case reports, cohort studies, and meta-analyses have linked COVID-19 to autoimmunity in general—and [systemic rheumatic diseases] in particular,” he said. “The notion that viruses are a trigger for—and linked to the pathophysiology of—autoimmune diseases has been an accepted tenet for over half a century. It is no surprise that SARSCoV-2 and COVID-19 have, from the onset of the pandemic, been implicated in a robust spectrum of autoimmune phenomena and even clinically manifested autoimmune diseases.”
This doesn’t mean that other factors don’t play a role but the link is important to look at and collect data about, as it’s expected there will be an emergence in the near future of autoimmune diseases in those who had COVID-19. “Incubation time for different autoimmune diseases varies,” Shoenfeld said. “There are studies that show that the incubation time for lupus, for instance, might be more than 10 years. With a disease called ascending cholangitis, the incubation time can be up to 25 years.”
A study conducted by PJ Utz at Stanford University, Chrysanthi Skevaki at Philipps University Marburg in Germany, and Eline Luning Prak at the University of Pennsylvania screened for a range of autoantibodies in blood samples from almost 150 individuals hospitalized with COVID-19 and 41 healthy volunteers.
The results of their research, which was funded by the National Institutes of Health, showed that nearly half of those hospitalized with severe COVID-19 had at least 1 type of autoantibody circulating in their bloodstream; in the healthy control group, just 15% of individuals had such antibodies.
Approximately 50 of the people with COVID-19 had blood samples drawn on more than 1 day, including the day they were first hospitalized. Investigators found that approximately 20% of those individuals had no autoantibodies present at the time of hospitalization but developed them over the course of their illness. In several of these individuals, the levels of autoantibodies were very high, close to the levels seen in autoimmune diseases.
Those researchers are continuing to study whether autoantibodies produced during COVID-19 could lead to autoimmune diseases later in life. And Shoenfeld predicts that more research will be done on this topic over the course of the next 5 years as physicians look for answers about the correlation between COVID-19 and the onset of autoimmune diseases and search for ways to better keep them at bay.
1. Chang R, Yen-Ting Chen T, Wang S-I, Hung Y-M, Chen H-Y, Wei C-CK. Risk of autoimmune diseases in patients with COVID-19: aretrospective cohort study. EClinicalMedicine. 2023;56:101783. doi:10.1016/j.eclinm.2022.101783