Children with Covid-19 can, in very rare cases, develop a severe form that triggers myocarditis. Researchers have succeeded in identifying a potential cause: genetic abnormalities.
“Genes associated with the occurrence of severe forms”
The severe inflammation started 4 to 6 weeks after infection with Sars-Cov-2. In its press release, the National Institute of Health and Medical Research, Inserm, states that for two-thirds of children who have contracted a severe form, “ this inflammatory syndrome affects the heart, leading to cases of myocarditis. “Several professionals in the medical and scientific sectors were then interested in these rare forms affecting children first” in England, in March 2020 […] in France, then all over the world “. On August 22, Santé Publique France identified 640 cases. To find explanations, the experts analyzed the blood taken from 56 children, including 30 who developed multisystem inflammatory syndrome and 21 with myocarditis, from April 6 to May 30, 2020.
As Mickaël Ménager from the Imagine Genetic Diseases Institute explains, the researchers used several cutting-edge techniques, including:
- an ultra-sensitive assay of cytokines (hormones of the immune system);
- characterization of blood cells;
- cell-by-cell genetic analysis.
According to the results published in the journal MED, they have “ thus identified the abnormal expression of several genes associated with the occurrence of severe forms of myocarditis “
Identify children at risk through a test
Three molecular abnormalities were highlighted in the different groups: a ” decrease in the number of monocytes and dendritic cells (white blood cells), as well as an increase in the level of inflammatory cytokines and overactivation of what is called the “NF-kB pathway” within these cells. However, the role of this pathway is to put genes into action so that they trigger an immune response. However, the system is overactivated, resulting in hyperinflammation. They discovered that these different phenomena are the cause of an abnormal expression of a hundred genes present in white blood cells. This scientific discovery is important because it could ” allow the development of tests to identify patients at risk of developing these severe cardiac inflammations. “
