Human leukocyte antigen (HLA) loci are highly polymorphic and determine differential features of the immune response in subjects from different regions. HLA genes have been proposed to determine genetic susceptibility to several diseases, particularly to viral infections. Moreover, it has been suggested that each ethnic group could have a different specificity of T-lymphocyte reactivity to the same viral infections. In this review, we analyzed the distribution of HLA types in countries of the Asian, European and North African region. Also, we studied the relation between these HLA polymorphisms and susceptibility to infection by the coronavirus. Our findings indicated that homozygosity would increase susceptibility to viral infections and, in some cases, to coronavirus infection. HLA types showing higher susceptibility were reported in Asian population, including China, Singapore, and Taiwan. In contrast, lower susceptibility HLA variants were detected among African populations, some Asian populations, and Mediterranean populations. The presented evidence along with the spread pattern of COVID-19 infection suggests that HLA genetic variants might be related to its infection susceptibility and severity. The investigation of HLA genetic variants distribution would be a useful tool to predict different populations’ susceptibility to viral infections.
5-HT2 and 5-HT7 receptor agonists facilitate plantar stepping in chronic spinal rats through actions on different populations of spinal neurons
