HLA Genotypes in Patients with Infection Caused by Different Strains of SARS-CoV-2.

The aggressive infectious nature of SARS-CoV-2, its rapid spread, and the emergence of mutations necessitate investigation of factors contributing to differences in SARS-CoV-2 susceptibility and severity. The role of genetic variations in the human HLA continues to be studied in various populations in terms of both its effect on morbidity and clinical manifestation of illness. The study included 484 COVID-19 convalescents (northwest Russia residents of St. Petersburg). Cases in which the responsible strain was determined were divided in two subgroups: group 1 (n = 231) had illness caused by genovariants unrelated to variant of concern (VOC) strains; and group 2 (n = 80) had illness caused by the delta (B.1.617.2) VOC; and a control group (n = 1456). DNA typing (HLA-A, B, DRB1) was performed at the basic resolution level. HLA-A*02 was associated with protection against infection caused by non-VOC SARS-CoV-2 genetic variants only but not against infection caused by delta strains. HLA-A*03 was associated with protection against infection caused by delta strains; and allele groups associated with infection by delta strains were HLA-A*30, B*49, and B*57. Thus, in northwest Russia, HLA-A*02 was associated with protection against infection caused by non-VOC SARS-CoV-2 genetic variants but not against delta viral strains. HLA-A*03 was associated with a reduced risk of infection by delta SARS-CoV-2 strains. HLA-A*30, HLA-B*49, and HLA-B*57 allele groups were predisposing factors for infection by delta (B.1.617.2) strains.

The effect of human leukocyte Antigens-DRB1 alleles on development of different tuberculosis forms in children.

Background: Nowadays, there is no doubt that the development of infectious process is determined not only by individual features of a human, but also by features of infection agent. It is commonly known that ability to form an adequate immune response is based on immunogenetic peculiarities of macroorganism. Methods: The immunogenetic study was performed in 228 children from 1 to 15 years old with different manifestations of tuberculosis (TB). Control group was consisted of 446 adult healthy donors-residents of the Northwestern region of Russia. Human leukocyte antigens (HLA)-DRB1* allelic genes were assessed in all individuals. Results: HLA-DRB1 alleles *01, *03, *11, *13, *07, and *15 were observed significantly rare in children with TB in comparison with healthy donors that may indicate their protective role in the development of the disease. It was also noticed that DRB1 *07 and *15 alleles were observed significantly rare in children with lung TB in comparison with other forms of disease that allows to assume a protective function of these alleles for lung TB with no influence on development of generalized TB. This assumption requires further researches. Conclusion: As a result of the study, statistically significant differences in the distribution of HLA-DRB1* alleles in children with TB in comparison with a control group for *01, *03, *11, *13, *07, *15, and *16 alleles were found. It may indicate their protective role in the development of TB. DRB1 *07 and *15 alleles were observed significantly rare in children with single TB than in children with generalized TB and healthy controls.