Distribution of HLA-A, -B, -C, -DRB1, -DQB1, -DPB1 allele frequencies in patients with COVID-19 bilateral pneumonia in Russians, living in the Chelyabinsk region (Russia).

In this population-based case-control study conducted in the Chelyabinsk region of Russia, we examined the distribution of HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1, in a group of 100 patients with confirmed COVID-19 bilateral pneumonia. Typing was performed by NGS and statistical calculations were carried out with the Arlequin program. HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 alleles were compared between patients with COVID-19 and 99 healthy controls. We identified that COVID-19 susceptibility is associated with alleles and genotypes rs9277534A (disequilibrium with HLA-DPB1*02:01, -02:02, -04:01, -04:02, -17:01 alleles) with low expression of protein products HLA-DPB1 (pc < 0.028) and homozygosity at HLA-C*04 (p = 0.024, pc = 0.312). Allele HLA-A*01:01 was decreased in a group of patients with severe forms of bilateral pneumonia, and therefore it may be considered as a protective factor for the development of severe symptoms of COVID-19 (p = 0.009, pc = 0.225). Our studies provide further evidence for the functional association between HLA genes and COVID-19.

Distribution of the HLA-DPB1 alleles in a Russian population living in the Chelyabinsk region (South Ural of Russia).

The purpose of this work was to establish the distribution of HLA-DPB1 alleles in Russians living in the Chelyabinsk region (Russia). DPB1 frequencies were determined in 100 unrelated Russian, living in the Chelyabinsk region. All subjects were healthy unrelated blood donors, between 18 and 55 years of age. Typing was performed by NGS (DNA-technology, Moscow). For population genetics analysis GENE[RATE] (https://hla-net.eu/tools/) software was used. DPB1*04:01 prevails in this population (gf = 0.3667). Other frequent HLA-DPB1 alleles were: DPB1*04:02, DPB1*02:01, DPB1*03:01 (gf = 0.1490; 0.1481; 0.1385, respectively). Rare alleles (gf ≤ 0.03) were DPB1*17:01, DPB1*01:01, DPB1*06:01, DPB1*14:01, DPB1*05:01, DPB1*13:01, DPB1*09:01, DPB1*10:01, DPB1*11:01, DPB1*23:01, DPB1*124:01, DPB1*15:01, DPB1*16:01, DPB1*105:01, DPB1*150:01.

Polymorphisms of HLA-DRB1, -DQA1 and -DQB1 in inhabitants of Astana, the capital city of Kazakhstan.

BACKGROUND: Kazakhstan has been inhabited by different populations, such as the Kazakh, Kyrgyz, Uzbek and others. Here we investigate allelic and haplotypic polymorphisms of human leukocyte antigen (HLA) genes at DRB1, DQA1 and DQB1 loci in the Kazakh ethnic group, and their genetic relationship between world populations. METHODOLOGY/PRINCIPAL FINDINGS: A total of 157 unrelated Kazakh ethnic individuals from Astana were genotyped using sequence based typing (SBT-Method) for HLA-DRB1, -DQA1 and -DQB1 loci. Allele frequencies, neighbor-joining method, and multidimensional scaling analysis have been obtained for comparison with other world populations. Statistical analyses were performed using Arlequin v3.11. Applying the software PAST v. 2.17 the resulting genetic distance matrix was used for a multidimensional scaling analysis (MDS). Respectively 37, 17 and 19 alleles were observed at HLA-DRB1, -DQA1 and -DQB1 loci. The most frequent alleles were HLA-DRB1*07:01 (13.1%), HLA-DQA1*03:01 (13.1%) and HLA-DQB1*03:01 (17.6%). In the observed group of Kazakhs DRB1*07:01-DQA1*02:01-DQB1*02:01 (8.0%) was the most common three loci haplotype. DRB1*10:01-DQB1*05:01 showed the strongest linkage disequilibrium. The Kazakh population shows genetic kinship with the Kazakhs from China, Uyghurs, Mongolians, Todzhinians, Tuvinians and as well as with other Siberians and Asians. CONCLUSIONS/SIGNIFICANCE: The HLA-DRB1, -DQA1 and -DQB1 loci are highly polymorphic in the Kazakh population, and this population has the closest relationship with other Asian and Siberian populations.