A recent study has revealed that approximately two percent of the population generate autoantibodies against type 1 interferons, mostly occurring later in life. This increases the vulnerability of individuals to viral illnesses such as COVID-19. The study was conducted by researchers from UZH in collaboration with a team from USZ, analyzing a large collection of historical blood samples.
Virus infections prompt immune system cells to release type 1 interferons, which serve as early messengers to alert uninfected cells and tissues about an approaching virus. This enables cells to prepare for combating the virus upon arrival.
Individuals with a defective type 1 interferon system may experience severe viral infections as their bodies are unable to mount a complete defense. Recent studies have shown that approximately 5 to 15 percent of individuals hospitalized with severe COVID-19 or influenza have a deficiency in their type 1 interferon response due to the presence of autoantibodies, which bind to type 1 interferons and impede their function.
Special Blood Samples for Analysis
“Our study aimed to determine why the immune systems of certain individuals turn against themselves and to comprehend the repercussions of having autoantibodies against type 1 interferons,” stated Benjamin Hale, the lead researcher and a professor at the Institute of Medical Virology at the University of Zurich (UZH).
The research team utilized a vast collection of frozen blood samples from the Swiss HIV Cohort Study, initially donated for HIV research purposes. They analyzed samples from around 2,000 adults who had provided blood samples biannually for several decades. Hale emphasized that this study was made possible by the unique biobank of stored longitudinal blood samples and well-documented clinical data, irrespective of the donors living with HIV.
Elderly Population is at Risk
Initially, the UZH team examined the blood samples for the presence of autoantibodies against type 1 interferons to determine who developed these autoantibodies, when this occurred, and how long they persisted in the blood.
The analysis revealed that about two percent of individuals produced autoantibodies against type 1 interferons during their lifetime, typically between ages 60 to 65. This validates prior studies indicating that the prevalence of autoantibodies against type 1 interferons may rise with age.
Furthermore, through clinical data analysis, researchers at the Department of Infectious Diseases and Hospital Epidemiology at the University Hospital Zurich (USZ) identified factors contributing to the development of autoantibodies against type 1 interferons. Those who developed these autoantibodies were more likely to produce antibodies against other proteins generated by their bodies, suggesting a loss of self-tolerance that can occur as individuals age.
Long-term Impact of Autoantibodies
The study highlighted that once formed, these autoantibodies persisted in individuals’ blood for the rest of their lives. Individuals with autoantibodies against type 1 interferons, even if developed as far back as 2008, were more susceptible to severe COVID-19 in 2020. This indicates that these autoantibodies have lasting consequences, compromising the type 1 interferon system and reducing immunity against viruses.
Understanding these risk factors could lead to future diagnostic tests to identify older individuals predisposed to developing this deficiency, aiding in preventive measures against autoantibody formation. Identifying individuals with autoantibodies against type 1 interferons could also help in prioritizing them for vaccines or antivirals to prevent severe viral infections.
