Associação de polimorfismos nos genes IL1B, IL6 e IL10 com periodontite

Abstract

Introduction: Periodontitis involves bone loss of support tissue and consequent loss of dental units, which significantly impacts the quality of life of individuals from all walks of life. The presence of dysbiotic microbial communities and an exacerbated immune response may result in the destruction of the microarchitecture of the supporting periodontium. Environmental and genetic factors are associated with the development of the disease, and it is necessary to elucidate the role of genetics in its development and progression. Objective: To investigate the association of polymorphisms of the IL1 B, IL6 and IL10 genes with periodontitis; and to determine the allelic frequencies of IL1 B, IL6 and IL10 polymorphisms in African, American and European populations. Materials and methods: Cross-sectional study, conducted with 506 adult individuals, classified with presence (n=117) or absence (n=389) of periodontitis, participants in the cohort of the Bahia Asthma Control Program (ProAR) in Salvador/Bahia – Brazil. Genomic DNA was extracted and genotyped using the Illumina Multi-Ethnic Global Array (MEGA, Illumina) platform. The platforms NCBI, RegulomeDB, ENCODE (Encyclopedia of DNA Elements), Haploview 4.2 and rSNPBase were consulted. Statistical analysis was performed using the PLINK 1.9 software and logistic regression was adjusted for age, obesity, mouth breathing habit, flossing, asthma and ancestry. For quality control, Hardy-Weinberg equilibrium <0.05, genotyping rate <0.98 and frequency of the lowest allele (MAF) <1% were used. Results: Two polymorphisms were associated with periodontitis in the IL1B gene. The rs3136557 A allele showed a negative association with periodontitis in both the additive and dominant models, respectively (OR = 0.48; CI 95% = 0.24-0.94) and (OR = 0.48; CI 95 % = 0.24-0.97). The rs1143630 T allele showed a positive association (OR = 1.49; CI 95% = 1.02-2.18) in the additive model, while the dominant model presented (OR = 1.61; CI 95% = 1.02-2.53). In the IL6 gene, the rs2069841 allele A polymorphism was positively associated with periodontitis in the additive model (OR = 2.61; CI 95% = 1.05-6.50) and in the dominant model (OR = 2.61; CI 95% = 1.05- 6.50). In the analysis of IL10 polymorphisms, no significant associations with periodontitis were found in the population studied. The frequency of the lowest A allele of rs3136557 is 8% in the studied population of Salvador, similar to the American population that has approximately the same frequency, while the African population has 5%. The rs1143630 (T allele) has a frequency of 20% in the population studied, while the African population presents 28%, the American and European population present 6%. The MAF of rs2069841 (A allele) was 2% in the studied group, similar to the African population that presented 3%. Conclusion: Polymorphisms in the genes of interleukins IL-1B and IL-6 were positively and negatively associated with periodontitis. No associations of IL10 gene polymorphisms with periodontitis were found in this population of the city of Salvador. The allelic frequency of polymorphisms is similar to those found in other populations, such as African and European.