An Increased Frequency in HLA Class I Alleles and Haplotypes Suggests Genetic Susceptibility to Influenza A (H1N1) 2009 Pandemic: A Case-Control Study

Abstract

Background The influenza A H1N1/09 pandemic infected a small number of exposed individuals, which suggests the involvement of genetic factors. There are scarce data available on classical HLA class I association with the influenza A H1N1/09 pandemic. Methods We analyzed the frequency of classical HLA class I alleles and haplotypes in A H1N1/09 influenza in a case-control study including 138 influenza patients (INF-P) and 225 asymptomatic healthy contacts (INF-C) simultaneously recruited. HLA class I typing was performed by high-resolution sequence-based typing method. Results Our analysis revealed higher frequency of C∗07:02:01, B∗39:06:02, C∗03:02:01, B∗44:03:01, B∗51:01:05, and B∗73:01 (p < 0.05; OR = 1.84–9.98) and of two haplotypes—A∗68:01:02-C∗07:02:01 (p = 1.05E − 05; OR = 23.99) and B∗35:01:01-C∗07:02.01 (p = 4.15E − 04, OR = 2.15)—in A H1N1/09 influenza subjects. A∗68:01:01 was exclusively present only in the INF-P group (5/138). A decrease in the frequency of C∗03:03:01, A∗11:01:01, B∗39:01:01, A∗24:02:01, C∗03:04:01, B∗51:01:01, and C∗07:01:01 (p < 0.05; OR = 0.12–0.52) and of haplotypes A∗02:01:01-B∗35:01:01-C∗04:01:01, A∗24:02:01-B∗35:01:01, B∗39:01:01-C∗07:02:01, and B∗40:02:01-C∗03:04:01 (p < 0.05; OR = 0.08–0.22) were observed in INF-P group. Conclusion Selective classical HLA class I allele and haplotype combinations predispose individuals towards susceptibility or protection against the influenza A H1N1/09 pandemic. This work has significant implications for accessing population transmission risk for A H1N1/09 or a similar strain breakout in the future.

HLA-B*44 and C*01 Prevalence Correlates with Covid19 Spreading across Italy

“…In this context, two individuals carrying the same antigen but different HLA profile may give rise to a completely different T-cell-mediated immune-response, since they may have completely different amounts of HLA-specific antigen-derived epitopes. This hypothesis has been confirmed in several studies concerning a number of different viruses as well as tumour antigens and autoimmune models [ 11 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ].…”

HLA Allele and Haplotype Frequencies in Three Urban Mexican Populations: Genetic Diversity for the Approach of Genomic Medicine

“…The human leukocyte antigen (HLA; known as MHC in other vertebrates) plays a central role in the recognition and presentation of antigens to the immune system and represents the most polymorphic gene cluster in the human genome [1]. This extensive polymorphism of the HLA genes among world populations results from selective pressures, including functional adaptations, particularly of bacteria, viruses, and parasites [2,3], which are particularly important in the understanding of human population variability. The HLA system in different populations is important in disease association, transplantation, and anthropological studies, among others.…”

Influenza A haemagglutinin specific IgG responses in children and adults after seasonal trivalent live attenuated influenza vaccination

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