COVID19 Infection increases the Risk of Developing Autoimmune Disease

Infection with Sars-COV-2 Virus Increases A Person’s Chance of Developing Autoimmune Disease

There has been a long held view that viral infections have the ability to trigger autoimmune diseases in those individuals with a genetic predisposition. It is thought that they do so by a mechanism involving “molecular mimicry”. Cytomegalovirus and Epstein–Barr virus are well known examples of viruses that have been linked to numerous autoimmune diseases.

Authors of a new study published in EClinical Medicine (part of the Lancet series) set out to determine if COVID 19 infection increases the risk of autoimmune disease. The authors did so by comparing new diagnoses in 888,463 cases who tested positive for COVID by PCR testing and 2,926,016 controls who did not have COVID 19 and tested negative.  The researchers intentionally did not include patients who had received COVID-19 vaccination throughout the study for clarity of interpretation. Participants were evaluated between January 1st, 2020 and December 31st, 2021, and followed for 6 months after the positive or negative diagnosis.

After matching, the COVID-19 cohort exhibited significantly higher risks of several autoimmune diseases as shown in the accompanying image. The approximate magnitude by which risk was increased in shown in the green box.

These include rheumatoid arthritis (aHR:2.98, 95% CI:2.78–3.20), ankylosing spondylitis (aHR:3.21, 95% CI:2.50–4.13), systemic lupus erythematosus (aHR:2.99, 95% CI:2.68–3.34), dermatopolymyositis (aHR:1.96, 95% CI:1.47–2.61), systemic sclerosis (aHR:2.58, 95% CI:2.02–3.28), Sjögren's syndrome (aHR:2.62, 95% CI:2.29–3.00), mixed connective tissue disease (aHR:3.14, 95% CI:2.26–4.36), Behçet's disease (aHR:2.32, 95% CI:1.38–3.89), polymyalgia rheumatica (aHR:2.90, 95% CI:2.36–3.57), vasculitis (aHR:1.96, 95% CI:1.74–2.20), psoriasis (aHR:2.91, 95% CI:2.67–3.17), inflammatory bowel disease (aHR:1.78, 95%CI:1.72–1.84), celiac disease (aHR:2.68, 95% CI:2.51–2.85), type 1 diabetes mellitus (aHR:2.68, 95%CI:2.51–2.85).

Subgroup Analyses

Subgroup analyses showed that these results were similar in males and females and were similar in different age groups as well (10-40 age group vs 41-64 age group and 65 years plus).

The authors also evaluated racial differences. COVID-19 infection was associated with a significantly higher risk of all autoimmune diseases and mortality in Whites, a higher risk of psoriasis and ankylosing spondylitis in Blacks, and a higher risk of systemic lupus erythematosus in Asians.

Conclusion

This study suggests that SARS-CoV-2 has the potential to be added to the list of viruses that can trigger autoimmune diseases. Whether vaccination can reduce this risk and whether current variants carry the same risk is unknown.

REFERENCE

Chang R et al. Risk of autoimmune diseases in patients with COVID-19: A retrospective cohort study. EClinicalMedicine. 2023 Feb;56:101783.