Objective: Single nucleotide polymorphisms (SNPs) in the promoter region of interleukin (IL)-10 gene, which codes for the anti-inflammatory cytokine IL-10, have been associated with its level of production in chronic periodontitis. The prevalence of promoter SNP genotypes is known in other populations with chronic periodontitis, while its association in the Indian population is not known. Hence, the present study was designed to investigate the prevalence of IL-10 promoter polymorphism in a racially defined group of Indians with severe chronic periodontitis as the Indian population is known to be genetically diverse.
Materials and methods: Genomic deoxyribonucleic acid was extracted from 46 nonsmoking patients with severe chronic periodontitis and 45 subjects with healthy periodontium. A SNP locus at -1087 of IL-10 was chosen, as this locus has been frequently associated with chronic periodontitis in other population. Genotyping was carried out using allele-specific polymerase chain reaction (AS-PCR), and the frequencies of genotype were analyzed between the groups.
Results: The distribution of genotype and allele frequencies showed significant differences between the study groups. The prevalence of genotype AA alleles at -1087 locus of IL-10 was significantly higher in severe chronic periodontitis patients compared to the healthy controls (P = 0.05).
Conclusion: The study has identified a positive association between the occurrence of AA allele at -1087 locus of IL-10 gene and severe chronic periodontitis in nonsmoking patients.
Keywords: Interleukin-10 alleles in periodontitis; interleukin-10 polymorphism; interleukin-10 polymorphism in periodontitis; promoter polymorphism in periodontitis; single nucleotide polymorphism in periodontitis.