In this study, DNA samples from HIV-1 infected and uninfected injecting drug users (IDUs) from Rio de Janeiro were PCR amplified to determine CCR5 genotypes based on the presence of the CCR5Δ32 mutation and typed for the HLA-B locus, in an attempt to assess possible associations between these genetic factors and susceptibility/resistance to HIV-1 infection.
The distribution of CCR5 genotypes between the two IDU groups did not differ. The homozygous mutant genotype Δ32/Δ32 was not found in this study. Except for HLA-B*45 (4.0 % vs. 3.0 % ; p = 0.04) and for B*51 (12.1 % vs. 4.4 % ; p = 0.002), no statistically significant differences were made evident when analyzing the frequencies of each HLA-B allele between Caucasian and non-Caucasian IDUs. The most frequent HLA-B alleles were B*15; B*35; B*44 and B*51. Although some differences in the allele frequencies could be observed between the two IDU groups, none of these was statistically significant. Therefore, no putative association between these genetic markers and susceptibility/resistance to HIV-1 infection could be made evident in the present study. So far, the assessment of genetic markers among the IDU population has been restricted to North American, European, and Asian studies and this report represents a pioneer descriptive study of the distribution of CCR5 genotypes and HLA-B alleles in Rio de Janeiro, Brazil.