MOSCOW, February 23 – RIA Novosti. Russian scientists from the Higher School of Economics were the first in the world to discover a genetic predisposition to the severe form of COVID-19. The research results are published in the journal Frontiers in Immunology.
T-cell immunity is one of the key mechanisms used by the human body to fight viral infections. Cellular immunity is based on the presentation, or detection, of viral peptides on the surface of infected cells, followed by the activation of T-lymphocytes capable of killing the virus.
The human leukocyte antigen class I (HLA-I) molecules are responsible for the presentation of the virus in human cells. The set of six such molecules is unique for each person and is inherited, so the ability to quickly detect viral peptides is largely determined by genetics. Simply put, if a set of alleles detects a virus well, then immune cells quickly find and destroy the virus. If, on the other hand, a person's genetic makeup does not cope well with such detection, it is more likely that a severe case of the disease will occur.
Researchers from the HSE Faculty of Biology and Biotechnology, together with colleagues from the Pirogov Russian National Research Medical University and the Moscow City Clinical Hospital No. 15 named after O. M. Filatova studied the relationship between the HLA-I genotype and the severity of COVID-19.
Using machine learning, they built a model that provides an integral estimate of the potential strength of the T-cell immune response to COVID-19. The authors suggested that if the set of HLA-I alleles allows the peptides of the SARS-CoV-2 virus to be effectively presented, the risk of developing a severe form of COVID-19 will be minimal, and vice versa.
To test the model, the authors analyzed the genotypes of more than 100 patients who had undergone COVID-19 and more than 400 healthy people from the control group. In each case, the program assessed the risk of a severe form of the disease in points from 0 to 100. Comparison with the actual clinical picture showed that the predictive model is very effective.
“In addition to the found correlations between genotype and severity of COVID-19, the proposed approach also helps to assess how a particular COVID-19 mutation might affect the development of T-cell immunity to the virus. For example, we can identify patient populations that are infected with new strains. SARS-CoV-2 can lead to more severe forms of the disease, “the head of the study, Professor Alexander Tonevitsky, Dean of the Faculty of Biology and Biotechnology at the Higher School of Economics, quoted in a press release.
In addition to analyzing the Moscow population, the high accuracy of the forecasts of the new model was also confirmed on an independent sample of patients from Madrid – the predictive risk assessment in patients suffering from severe COVID-19 was significantly higher than in patients with moderate and mild cases of the disease.