Autoantibodies in severe COVID-19: Possible culprits in long-term COVID-19 cases

Stanford University researchers released information indicating that in hospitalized patients with severe COVID-19, the virus can cause production of autoantibodies that can, in effect, cause the body to attack itself and result in inflammatory diseases.

Stanford University researchers released information indicating that in hospitalized patients1 with severe COVID-19, the virus can cause production of autoantibodies that can, in effect, cause the body to attack itself and result in inflammatory diseases, according to first author Sarah Esther Chang, PhD, and colleagues from the Department of Medicine, Division of Immunology and Rheumatology, and the Institute for Immunity, Transplantation and Infection at Stanford University School of Medicine in Stanford, California.

This finding may account for the long-term symptoms seen in some patients.

“This suggests that inflammation in response to SARS-CoV-2 infection promotes tissue damage in the acute phase and potentially some of the long-term sequelae,” the authors said.


Immunoglobulin G (IgG) autoantibody measurement

The investigators developed 3 protein arrays to measure the IgG autoantibodies associated with connective tissue diseases, anti-cytokine antibodies, and anti-viral antibody responses in serum samples.

The investigators also reported that autoantibodies were identified in about half of the 147 hospitalized patients with COVID-19 in contrast to less than 15% of 41 healthy controls.

When these autoantibodies are present, they mostly target autoantigens associated with myositis, systemic sclerosis, and overlap syndromes, i.e., rare disorders.

However, a subset of autoantibodies that target traditional autoantigens or cytokines develop for the first time after a SARS-CoV-2 infection.

“Autoantibodies track with longitudinal development of IgG antibodies recognizing SARS-CoV-2 structural proteins and a subset of non-structural proteins, but not proteins from influenza, seasonal coronaviruses or other pathogenic viruses. We conclude that SARS-CoV-2 causes development of new-onset IgG autoantibodies in a significant proportion of hospitalized COVID-19 patients and are positively correlated with immune responses to SARS-CoV-2 proteins,” the authors concluded.

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Reference

1. Chang SE, Feng A, Meng W, et al. New-onset IgG autoantibodies in hospitalized patients with COVID-19. Nat Commun 2021;12:5417; https://doi.org/10.1038/s41467-021-25509-3