In a recent publication in the journal Clinical Rheumatology, researchers conducted a large cohort study to examine whether the risk of developing an incident autoimmune disease is augmented in patients with prior COVID-19 disease compared with those without COVID-19.

The authors wrote, “To date, different respiratory, cardiovascular, neurological, and mental diseases as well as various symptoms in the context of long/post-COVID have been studied with routine health care data. The group of autoimmune diseases is less discussed in the literature, although autoantibodies could be found in patients after SARS-CoV-2 infection, e.g., anti-type I IFNs [interferons], anti-IFN-α, and anti-nuclear antibodies (ANAs).”

The matched cohort study comprised patients who had received a confirmed COVID-19 diagnosis from a polymerase chain reaction test through December 31, 2020. The control group, meanwhile, was comprised of patients without a confirmed infection. Patients were matched 1:3 to control patients without COVID-19 based on age, biological gender, and whether there was a history of autoimmune diseases. Both study groups were followed until June 30, 2021.

In this study, researchers compared the rates of newly diagnosed autoimmune disease between individuals with and without documented SARS-CoV-2 infection. The researchers employed the four quarters before the index date until the end of follow-up to examine the onset of autoimmune diseases during the postacute period. Incidence rates per 1,000 person-years were determined for each outcome and patient group. Poisson models were employed to project the incidence rate ratios (IRRs) of developing an autoimmune disease conditional on a preceding diagnosis of COVID-19.

The researchers evaluated 64 potential health outcomes, including 41 autoimmune diseases. The follow-up period was 3 to 15 months after a confirmed diagnosis.

In total, 641,704 patients with COVID-19 were included in the study. With regard to their findings, the authors wrote, “For the more common autoimmune diseases, the highest estimates were found for rheumatoid arthritis, Sjögren disease, Graves’ disease, and Hashimoto thyroiditis, with an approximately 40% higher rate compared to a matched cohort without SARS-CoV-2 infection.”

The authors indicated that individuals without a prior autoimmune disease and COVID-19 had a 43% higher probability of developing an incident autoimmune disease than controls, while those with any preexisting autoimmune disease and COVID-19 had a 23% greater probability of being diagnosed with another autoimmune disease.

The researchers also noted that the estimate was comparable for common autoimmune diseases, such as Hashimoto thyroiditis, rheumatoid arthritis, or Sjögren syndrome, and the greatest IRR was observed for autoimmune diseases of the vasculitis group. Moreover, a greater risk for incident autoimmune disease was more likely in individuals with a more severe course of COVID-19.

Based on their findings, the authors wrote, “In the 3 to 15 months after acute infection, patients who had suffered from COVID-19 had a 43% (95% CI: 37–48%) higher likelihood of developing a first-onset autoimmune disease, meaning an absolute increase in the incidence of 4.50 per 1,000 person-years over the control group. COVID-19 showed the strongest association with vascular autoimmune diseases.”

The authors concluded that SARS-CoV-2 infection is correlated with an augmented risk of developing new-onset autoimmune diseases after the acute phase of infection.

The authors wrote, “Further epidemiologic, clinical, and basic science research is warranted to determine whether SARS-CoV-2 infection triggers the onset of autoimmune disease, to identify the underlying mechanisms and persons at risk, and to investigate effective means of prevention or early treatment.”

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.