HLA-C Single Nucleotide Polymorphism Associated with Increased Viral Load Level in HIV-1 Infected Individuals from Northeast Brazil

Background: Genetic variations in Human leukocyte antigen C (HLA-C), Zinc ribbon domain containing 1 (ZNRD1) and its antisense RNA (ZNRD1-AS1) genes are known to influence the HIV-1 replication and disease progression. Objective and Method: We evaluated the distribution of HLA-C (rs10484554, rs9264942) and ZNRD1 (rs8321) and ZNRD1-AS1 (rs3869068), single nucleotide polymorphisms (SNPs) in 266 HIV-1-infected and 223 unexposed-uninfected individuals from Northeast Brazil and their relation to HIV-1 infection, CD4 T cells count and viral load pre-treatment. Results: HLA-C SNPs were in Linkage Disequilibrium (D'=0.84), constituting four possible haplotypes. Our results showed that HLA-C, ZNRD1 and ZNRD1-AS1 SNPs as well as HLA-C haplotypes frequencies were not significantly different between HIV-1-infected and unexposed-uninfected individuals. In addition, we analyzed HLA-C and ZNRD-1 and ZNRD1-AS1 SNPs considering CD4+ T cell counts and viral load before the antiretroviral treatment. Individuals carrying HLA-C rs9264942 TT genotype showed a significant increased level of HIV-1 viral load pre-treatment, in comparison with individuals carrying the CC genotype (p-value = 0.0092). Finally, we stratified our findings according to CCR5 Delta 32 allele presence along with the studied SNPs: no statistically significant influence over viral load pre-treatment has been found. Conclusion: The association between HLA-C rs9264942 SNP and viral load prior treatment in an admixed population from North East Brazil was in agreement with findings from previous studies obtained on different ethnic groups; however more studies should be conducted in order to clarify how HLA-C impair the HIV-1 replication.