A team led by researchers from the Faculty of Biology and Biotechnology at Higher School of Economics University in Russia developed the first study that revealed that severe cases of Covid-19 may be related to a genetic inheritance in the identification of Sars-CoV-2 in cells.
Published not newspaper Frontiers in Immunology, research has shown that genetic predisposition is associated with the T cell immunity system, one of the body’s main defense mechanisms against the virus. The presentation of the foreign element in cells (antigen) is important for the activation of T lymphocytes, responsible for killing cells infected by the virus.
Class I human leukocyte antigen molecules (HLA-I) are the group of molecules responsible for identifying and distinguishing everything that is in the body itself from what is external to it. Present on the surface of all cells, six HLA-I molecules form a unique set for each individual, which is determined from the genes received by their parents.
This means that the set of HLA-I that detects the virus well can act in the destruction of the infected cells more quickly and effectively. Otherwise, a severe condition is more likely to develop. What the scientists investigated was the possible direct connection between the severity of the disease and the performance of HLA-I in identifying Sars-CoV-2.
They put together a model to evaluate this relationship and analyzed genotypes of more than 100 patients who suffered from Covid-19, in addition to more than 400 healthy people (who formed the control group).
The analysis worked based on a scoring system: the lower the ability of the HLA-I alleles to present Sars-CoV-2 to cells, the more points the study participant received. In addition to the population of Moscow, Russia, the researchers used the model on a sample of patients in Madrid, Spain.
In both assessments, the score of people who progressed to severe illness was significantly higher than that of patients with mild and moderate cases. The researchers concluded that the risk score obtained by the established model proved to be highly effective and accurate in predicting the severity of Covid-19.
“In addition to the correlations found between the genotype and the severity of Covid-19, the suggested approach also helps to assess how a certain mutation [do vírus] it can affect the development of T cell immunity, ”says Alexander Tonevitsky, a researcher at the Faculty of Biology and Biotechnology at HSE University, in a statement. “We can, for example, detect groups of patients for whom infection with new strains of Sars-CoV-2 can lead to more severe forms of the disease,” he adds.