COVID-19 Severity and Autoantibody Production

April 25, 2023

The link between SARS-CoV-2 and the production of autoantibodies has been well established. To better characterize the immunopathology of COVID-19, researchers studied the range of autoantibodies triggered by a SARS-CoV-2 infection, as well as infection severity.

The study’s sample size included 161 COVID-19 patients, none of which received a SARS-CoV-2 vaccine. Participants were asked to complete an online survey with their symptoms and infection outcomes; based on their answers, it was determined that 72 participants experienced mild COVID-19, 61 moderate and 28 severe. 77 age and sex-matched SARS-CoV-2 negative controls were included in the study. Sera samples, collected at a “similar average” time interval across all participants, were tested for IgG and IgA antibodies, rheumatoid factor, and ENA antibodies, amongst others.

The data indicates a “breakdown of physiological autoantibody levels in patients with COVID-19 that paralleled disease severity.” Generally, the autoantibodies in patients with mild COVID-19 only slightly differed compared to healthy controls. Patients with moderate COVID-19 exhibited more elevated autoantibody counts, whereas those with severe COVID-19 were observed to have the highest levels of autoantibodies.

To understand the impact of age on disease severity, researchers separated the control group and COVID-19 patients by age (under and over 50 years), and found that severe infection induced a higher autoantibody count in older patients (namely IgA and IgG).