Autoantibodies & Long Covid

June 20, 2023

A recent paper shared the results of a longitudinal study on autoantibodies in those with long Covid. Researchers measured levels of a variety of autoantibodies (ANA) and inflammatory markers in 106 patients who experienced a COVID-19 infection, as well as 34 patients who had a non-COVID infection, at 3, 6, and 12 months post-infection and compared them to 22 healthy controls. No participants included in the study had a personal or family history of autoimmune disease.

At three months post-COVID infection, approximately one-third of patients had at least one type of IgG autoantibody. 43% of autoantibodies identified in these patients have been associated with autoimmune diseases. Furthermore, the presence of autoantibodies correlated with the severity of COVID-19 infection, with those who were hospitalized or admitted to the ICU having higher levels of ANAs. 

Autoantibody levels were observed to decrease over time, and severity of COVID-19 infection was no longer predictive of autoantibody levels after 12 months. As a point of interest, some patients displayed new autoantibodies at one year post-Covid that were not recorded at the three or six month intervals. This suggests that there may be an autoimmune process at work. 

Two autoantibodies (anti-U1-snRNP and anti-SS-B/La) were identified that are predictive of long Covid symptoms (fatigue and shortness of breath, respectively). A couple of inflammatory mediators (TNFα and D-dimer) correlated with ANA levels and were also elevated in symptomatic patients. 

The authors of the paper emphasize the ongoing need for research on the mechanisms of long Covid and for better symptom screening in future studies as more long Covid symptoms have become apparent since this study began.