For two years, research has continued to advance on Covid-19. Among the paths taken, that of the identification of biological risk factors for serious forms. Thanks to their work, Dr Laurent Abel and Pr Jean-Laurent Casanova* have noticed that around a quarter of the severe forms of Covid-19 are due to immunological or genetic defects leading to a malfunction of interferons (IFN) type I, which constitute the first immunological barrier against viral infections. Among these defects, the presence of auto-antibodies is the most frequent.
“Their presence, which characterizes autoimmune diseases, prevents interferons from acting against the virus as they should do in normal times,” explains Dr. Abel. “15% of Covid patients with a severe form are affected”. Another important element: auto-antibodies “are present in 1% of the general population and up to 6 to 7% in those over 80”, he continues. And being a carrier increases the risk of a severe form by 50 to 100 times.
Identify patients at risk as soon as possible
Hence the major interest of being able to identify the individuals concerned as quickly as possible. “Because when the interferons are prevented from acting, it is necessary to treat quickly otherwise it is too late”, explains Dr. Abel. The tests exist, and Dr. Abel’s team is working in partnership with the bioMérieux laboratory to develop ready-to-use diagnostic tests for the precise and large-scale detection of autoantibodies against type IFNs. I.
These tests will be validated and implemented by Cerba HealthCare and its network of Cerballiance medical biology laboratories. “We will thus be able to integrate these innovations into the diagnostic routine and provide clinicians and patients more quickly with broad screening tools that will help optimize prevention and adapt care and treatment in people at risk” , explains Jérôme Sallette, scientific director of Cerba HealthCare.
These tests could also help detect and manage people at risk for other viral diseases, or anticipate the adverse effects of live attenuated viral vaccines (for example, the yellow fever vaccine before travel, or the vaccine against chickenpox after age 50).
*from the “human genetics of infectious diseases” laboratory, at the Imagine Institute located at the Necker-Enfants Malades Hospital AP-HP
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