A collaborative effort of over 150 scientists from over 20 countries, including CITF-funded researcher Dr. Donald Vinh from McGill University Health Centre and the Research Institute of the McGill University Health Centre, has led to the identification of a surprisingly high prevalence of a type of antibody that has been linked to fatal outcomes of COVID-19. These autoantibodies – antibodies that mistakenly target a person’s own tissues or proteins – block a key part of the antiviral immune response. In a recent Science Immunology article, researchers report that these rogue antibodies, neutralizing type I interferon, were discovered in almost 20% of all deceased patients – but they were not found in subjects with asymptomatic infections.
- This type of autoantibody can be found naturally in healthy individuals, independent of SARS-CoV-2 infection, but is more prevalent in individuals over the age of 80.
- Autoantibodies can be found in 0.2-1% of individuals <70 years, 1-2% of individuals between 70 and 79 years, and 3-6% of individuals >80 years.
- These antibodies were found in over 10% of all patients with critical COVID-19 pneumonia, in 20% of patients >80 years with critical COVID-19 and in 18% of all deceased patients. Comparatively, these autoantibodies were not found in any subject with an asymptomatic infection.
The presence of these auto-antibodies to type I interferon may explain some of the variability observed in the wide range of severity of COVID-19 illness in older people. Researchers also suggested that some people may be genetically predisposed to produce these antibodies. In addition, the more common presence of these rogue antibodies among men compared to women may also explain why COVID-19 seems to hit men harder.
Detection of autoantibodies may also have implications for the timing of treatment and vaccination. Testing for the presence of these antibodies is relatively easy and inexpensive, and their presence may help clinicians determine which patients may benefit from earlier treatment and/or hospital admission, as well as whether certain antiviral therapies can help boost their weakened immune responses.
Bastard P, …, [Vinh DC] …, et al. Autoantibodies neutralizing type I IFNs are present in ~4% of uninfected individuals over 70 years old and account for ~20% of COVID-19 deaths. Science immunol. 2021;6(62):eabl4340.