Impact of <i>IL-6</i> and <i>IL-6r</i> variants on HIV-1 susceptibility and progression to AIDS: a case-control study in a Moroccan population

Abstract

Interleukin-6 (IL-6), a pro-inflammatory cytokine, is an important regulator of the inflammatory immune response. We aimed to assess the association of common single nucleotide polymorphisms (SNPs) in <i>IL-6</i> (rs1800795 G > C, rs1800797 A > G) and <i>interleukin-6 receptor</i> (<i>IL-6R</i>) (rs2228145 A > C) genes with HIV-1 infection, AIDS progression, and response to treatment. In this case-control study involving 199 individuals living with HIV-1 and 200 HIV-uninfected controls, we conducted genotyping of <i>IL-6/IL-6R</i> SNPs using TaqMan real-time PCR assays. Soluble IL-6 levels were measured using ELISA. No associations were found between the investigated SNPs and HIV infection. However, a significant association was noted between the C-G and G-A haplotypes and susceptibility to HIV-1 infection. Additionally, a significant association was revealed between HIV-1 RNA viral loads and <i>IL-6</i> SNP G > C in the post-treatment HIV group. Interestingly, we observed a significant association between the investigated SNPs and protection against progression to AIDS, namely the IL-6 G > A SNP in its recessive model and the <i>IL-6R</i> A > C SNP in its codominant and dominant models. Nevertheless, we found no significant differences between IL-6 levels and the different genotypes and alleles of the <i>IL-6</i> gene either before or after combination antiretroviral therapy. <i>IL-6</i> promoter haplotypes are associated with susceptibility to HIV-1 infection. Furthermore, <i>IL-6</i> A > G and <i>IL-6R</i> A > C polymorphisms have been associated with protection against AIDS progression. Interestingly, the <i>IL-6</i> G > C SNP may affect the response to treatment in people living with HIV-1.