Influence of HLA-G polymorphisms in human immunodeficiency virus infection and hepatitis C virus co-infection in Brazilian and Italian individuals

•HLA-G 3′ UTR genotypes and haplotypes are associated to risk of HIV infection.•The HLA-G 14bp insertion is associated with risk of HCV co-infection in HIV patients.•It is important to consider ethnicity in HIV risk association studies. This study aimed to investigate the role of Human Leukocyte Antigen (HLA)-G in the susceptibility to HIV-1 infection through the analysis of the HLA-G 3′ untranslated region (UTR) polymorphisms 14bp insertion/deletion (rs66554220) and +3142C>G (rs1063320). We analyzed 582 HIV-1 infected patients and 626 uninfected individuals from Brazil and Italy in a case-control study. HLA-G polymorphisms were genotyped using PCR, PCR-RFLP assays or direct sequencing. All analyses were stratified by ethnicity. Genotypic, allelic and diplotypic frequencies were compared between HIV-1 infected subjects and controls using Chi-square or Fischer exact tests. Also, haplotypic frequencies were estimated using MLocus software. African-derived HIV-infected individuals presented a higher frequency of the 14bp insertion allele as compared to non-infected individuals (0.468 versus 0.373, respectively; pBonf=0.010). A higher frequency of the 14bp insertion +3142G (insG) haplotype (0.456 versus 0.346, p