Interleukin gene polymorphisms and susceptibility to HIV-1 infection: a meta-analysis

Some subjects are repeatedly exposed to human immunodeficiency virus (HIV), yet they remain uninfected. This suggests the existence of host-resistancemechanisms. The current study synthesizes the evidence regarding the association between interleukin (IL) gene polymorphisms and HIV susceptibility. Medline, Scopus and the Web of Science databases were systematically searched, and a meta-analysis of case-control studies was conducted. Univariate and bivariate methods were used. The literature search identified 42 eligible studies involving 15,727 subjects. Evidence was obtained on eight single-nucleotide polymorphisms (SNPs): IL1A-889 C>T (rs1800587), IL1B + 3953/4 C>T (rs1143634), IL4 - 589/90 C>T (rs2243250), IL6 - 174 G>C (rs1800795), IL10 - 592 C>A (rs1800872), IL10-1082 A>G (rs1800896), IL12B - 1188 A>C (rs3212227) and IL28B C>T (rs12979860). The IL1B + 3953/4 C>T variant appears to increase the risk of HIV acquisition, under the assumption of a recessive geneticmodel (odds ratio (OR): 4.47, 95% CI: 2.35-8.52). The AA homozygotes of the IL10 - 592 C>A SNP had an increased, marginally nonsignificant, risk (OR: 1.39, 95% CI: 0.97-2.01). It reached, however, significance in subanalyses (OR: 1.49, 95% CI: 1.04-2.12). Finally, the well-studied hepatitis C virus (HCV) infection IL28B (rs12979860) CT/TT genotypes were associated with a 27% decrease in HIV infection risk, especially in populations infected with HCV(OR: 0.73, 95% CI: 0.57-0.95). Interleukin signalling is perhaps important in HIV infection and some interleukin genetic variants may affect the risk of HIV acquisition. Approaches targeting specific genes and genomewide association studies should be conducted to decipher the effect of these polymorphisms.