CXCR-2 is a receptor of interleukin-8, which is involved in acute and chronic inflammatory processes. Polymorphisms in the CXCR2 gene have been associated with chronic inflammatory conditions. The aim of this study was to investigate whether the þ785(C=T), þ1208(T=C), and þ1440(G=A) single-nucleotide polymorphisms (SNPs) in the CXCR2 gene, as well as their haplotypes, are associated with susceptibility to periodontitis in Brazilians. DNA was extracted from the buccal epithelial cells of 487 individuals (control ¼ 215; periodontitis ¼ 272). The SNPs were investigated using the sequence-specific primer-polymerase chain reaction method. Associations between the polymorphisms and subject phenotypes were analyzed using the chi-squared statistical test, followed by univariate and multivariate logistic regression modeling. Haplotypes were reconstructed using the expectation-maximization algorithm, and differences in haplotype distribution between the groups were analyzed to estimate genetic susceptibility for periodontitis development. Univariate and multivariate analysis revealed that age, skin color, and smoking status were associated with periodontitis. The þ1440 GG genotype was shown to be protective against periodontitis in both univariate and multivariate analysis (odds ratio [OR] adjusted ¼ 0.42; 95% confidence interval [CI] ¼ 0.19, 0.96). A similar relevant result for the þ1440 GG was obtained in an alternative analysis considering a subgroup containing only white nonsmokers (OR ¼ 0.37; 95% CI ¼ 0.15, 0.92). White nonsmokers with the CTG=TCG haplotype appeared to be genetically protected against the development of periodontitis (OR ¼ 0.29; 95% CI ¼ 0.09, 0.89), while those carrying the CTG=TCA haplotype were more susceptible to the development of periodontitis (OR ¼ 2.08; 95% CI ¼ 1.24, 3.51). In conclusion, the þ1440 SNP and some haplotypes are associated with periodontitis in Brazilian individuals.

BackgroundThe chemokine receptor 1 CXCR-1 (or IL8R-alpha) is a specific receptor for the interleukin 8 (IL-8), which is chemoattractant for neutrophils and has an important role in the inflammatory response. The polymorphism rs2234671 at position Ex2+860G > C of the CXCR1 gene causes a conservative amino acid substitution (S276T). This single nucleotide polymorphism (SNP) seemed to be functional as it was associated with decreased lung cancer risk. Previous studies of our group found association of haplotypes in the IL8 and in the CXCR2 genes with the multifactorial disease chronic periodontitis. In this study we investigated the polymorphism rs2234671 in 395 Brazilian subjects with and without chronic periodontitis.FindingsSimilar distribution of the allelic and genotypic frequencies were observed between the groups (p > 0.05).ConclusionsThe polymorphism rs2234671 in the CXCR1 gene was not associated with the susceptibility to chronic periodontitis in the studied Brazilian population.