Background and objectives: Polymorphisms in the genes that encode for the CCR2 chemokine receptor and its natural ligand CCL2 have been shown to influence the natural history of HIV-1 infection, although data are inconsistent. Our aim was to determine whether functionally active CCR2 and CCL2 genetic variants influence the risk of infection and disease progression in a cohort of white Spaniards.
Patients and methods: This was a multicenter genetic association case-control study. Two single nucleotide polymorphisms (SNPs), V64I (G > A) of the CCR2 gene and -2518 (A > G) of the CCL2 gene, were assessed in 318 individuals: 73 HIV-1-infected long-term nonprogressors (LTNPs) of >16 years duration, 109 HIV-1-infected usual progressors (UPs), 36 heavily exposed to HIV-1 but uninfected individuals (EUs), and 100 control subjects. The distribution of the CCR5Delta32 allele was also assessed. Genotyping was performed using polymerase chain reaction (PCR) restriction fragment length polymorphisms (RFLPs) or PCR and automatic sequencing analysis methods on white blood cell DNA. Genotype and allele frequencies were compared by the chi2 test and the Fisher exact test.
Results: CCR2 genotype distribution and allele frequencies showed nonsignificant differences between groups. The distribution of CCL2 alleles showed no significant differences between groups. HIV-1-infected individuals had, however, a significantly higher prevalence of the variant homozygous CCL2 GG genotype compared with EUs (P = 0.02). This result persisted when we studied only individuals with wild-type CCR5. Genotype and allele distribution of CCL2 was similar in HIV-1-infected UPs and LTNPs.
Conclusions: In our cohort of white Spaniards, homozygosity for the variant CCL2-2518GG genotype is overrepresented in HIV-1-infected subjects.