Prevalência do polimorfismo -1031 T>C do gene TNFA em um grupo de diabéticos tipo I e sua relação com a periodontite severa

• Autor(a) principal: Oliveira, Luciano Santos
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/14015
• topic: Periodontal Disease; TNFA; Genetic Polymorphism; Diabetes; TIDM; Periodontitis; Doença Periodontal; TNFA; Polimorfismo Genético; Diabetes; DMI; Periodontite; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA

Diabetes mellitus and periodontal diseases are highly prevalent worldwide. Periodontal disease (PD) combines a group of chronic inflammatory conditions induced by microorganisms that leads to gingival inflammation, periodontal tissue destruction and alveolar bone loss. Diabetes mellitus (DM) is a term used to describe a group of metabolic disorders associated to glucose intolerance and inappropriate carbohydrate metabolism. Once PDs could act in a similar way to other systemic infectious states increasing diabetes severity, a possible correlation between both has been considerate around the world. Single nucleotide polymorphisms (SNPs) have been studied in relation to several diseases. In periodontitis, it is believed to be involved in an exacerbated inflammatory response due to bacterial challenge, modifying the host susceptibility. In this study, the prevalence of periodontal disease was evaluated in type I diabetes patients (TIDM). Further on, the SNP in the promoter region of the TNFA gene (-1031T>C) was analyzed and its importance to destructive periodontal disease was considered. The test group was formed by type I diabetic patients (TDG, n=113) and the control group was composed by non-diabetic patients (ND, n=73). For the genetic polymorphism analysis a subgroup was taken from the test group (DG, n=58) and compared to the ND group. The following clinical and demographic parameters were assessed: percentage of sites with periodontal pocket depth (PPD) &#61619; 6.0mm; gingival index (GI); radiographic bone loss (RBL); smoking habits; diabetes duration; age; bone mass index (BMI); number of admissions and number of teeth. Blood samples and oral epithelial cells were collected from 58 patients of the test group and 73 controls. After genomic DNA extraction and amplification of the genomic region of interest by PCR (Polymerase Chain Reaction), the TNFA 1031T>C polymorphism was analyzed by BbsI RFLP (Restriction Fragment Length Polymorphism). Analysis of the digestion products were performed by 8% polyacrylamide gel electrophoresis. The statistical analysis of the genotypes and allelic frequencies along with the clinical and epidemiological data between the two groups were done through the Mann-Whitney and Chi-square tests. The study groups are in Hardy-Weinberg equilibrium. In the ND group, the following genotypic frequencies were found: 78.1% (T/T); 20.5% (T/C) e 1.4% (C/C), while for the D group, they were: 42.4% (T/T); 37.3% (T/C) e 20.3% (C/C). The frequencies of T allele in the D and ND groups were 0.610 and 0.883, respectively. It was not possible to find any correlation between the -1031 T>C promoter polymorphism of the TNFA gene and the presence of periodontitis in type I diabetic patients. However the studied polymorphism showed to be significantly related (p<0.0001 and OR=4.85 95%CI 2.271-10.338) to the presence of type I diabetes mellitus.