Investigação da associação de polimorfismos no gene Interleucina 17 Alfa com o estado periodontal e perfil bioquímico do paciente
Carregando...
Data
2020-04-10
Autores
Rimachi Hidalgo, Marco Antonio
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Em todo o mundo continua-se a buscar evidências de suscetibilidade genética à periodontite (P) em diferentes populações, pois é importante levar em consideração as diferenças genéticas entre as diversas etnias. Além disso, também há grande interesse da comunidade científica em avaliar potenciais inter-relações entre a periodontite e alterações sistêmicas como o Diabetes Mellitus tipo 2 (T2DM, type 2 Diabetes Mellitus). Estudos enfocando polimorfismos genéticos são importantes principalmente para o entendimento que desempenham na modulação da resposta do hospedeiro frente à ação de micro-organismos periodontopatogênicos. O gene Interleucina 17 Alfa (IL17A), que codifica a citocina pró-inflamatória comumente referida como IL-17, é produzida por um subconjunto de células T auxiliadoras (T helper) Th1/Th0 e secretada pelas células Th17, implicadas na vigilância imunológica nas superfícies mucosas e implicada na inflamação crônica. O objetivo deste estudo é investigar três polimorfismos no gene IL17A para avaliar se podem estar associados com a suscetibilidade genética à periodontite na presença (ou não) de T2DM, e relacioná-los com o perfil bioquímico e clínico periodontal do paciente. Considerando o cálculo amostral, foram investigados pacientes com T2DM e periodontite severa ou moderada (Grupo T2DM_P, n=199 pacientes); e para comparação dos resultados foram considerados pacientes sem T2DM com periodontite severa ou moderada (Grupo PERIODONTITIS, n=342), e também pacientes sem T2DM e sem periodontite ou periodontite leve, ou seja, pacientes saudáveis (Grupo HEALTHY, n=338), totalizando 879 indivíduos. Após exame periodontal completo foi obtido o bochecho de cada paciente para extração do DNA por Acetato de Amônio. Foram investigados três polimorfismos de nucleotídeo único (single nucleotide polymorphism - SNP) no gene IL17A por meio do sistema de genotipagem TaqMan utilizando PCR em tempo real. Uma parte dos pacientes realizaram exames bioquímicos do perfil glicêmico e lipídico. Após análise das frequências de alelos e genótipos por meio do software PLINK, foi avaliado o Equilíbrio de Hardy-Weinberg de cada SNP. Os grupos foram comparados entre si, em relação às frequências alélicas e genotípicas realizando análises de regressão logística múltipla utilizando o programa STATA, e ajustando-se às variáveis idade, gênero, tabagismo e perfil bioquímico. Como resultado da comparação entre o grupo HEALTHY versus T2DM_P, a regressão logística múltipla estratificada para o hábito de fumar, demonstrou que pacientes fumantes com genótipo GG para o SNP rs3819024 do gene IL17A tinham maior chance de apresentar periodontite associado a T2DM (OR=6.60; IC 95%=1.31-33.01; p=0.02). Resultado semelhante foi obtido para pacientes fumantes na comparação PERIODONTITIS versus T2DM_P, indicando associação do genótipo GG com T2DM (OR=5.05; IC 95%=1.36-18.82; p=0.01). Por meio do software PLINK foi verificado o desequilíbrio de ligação entre cada SNP, constatando-se que os mesmos apresentavam-se como haplótipos. A distribuição dos haplótipos foi comparada entre os grupos por regressão logística múltipla demonstrando que indivíduos portadores do conjunto de haplótipos mais raros (<3%) eram mais suscetíveis a Periodontite juntamente com T2DM (OR=2.30; IC 95%=1.16-4.55, p= 0.01), assim como ao T2DM isoladamente (OR=2.98; IC 95%=1.62-5.48, p = 0.00). Conclui-se pelos resultados obtidos com pacientes fumantes e ex-fumantes que o SNP rs3819024 do gene IL17A demonstra associação com o diabetes mellitus tipo 2 isoladamente, e também como comorbidade da periodontite, no entanto o amplo intervalo de confiança observado indica que tal resultado necessita ser comprovado em uma população maior. A associação dos haplótipos raros com as patologias estudadas pode ser um resultado biologicamente espúrio, pois foi obtido pela soma dos diferentes haplótipos raros, de modo que se um deles for considerado sozinho, a associação certamente será perdida, esclarecendo que o número de pacientes em cada grupo que carregam os haplótipos raros é menor do que o número calculado para obter o poder do estudo o que é normal.
Worldwide, evidence continues to be sought genetic susceptibility to periodontitis (P), because as genetic differences between different ethnicities tend to influence such susceptibility. Also, there is considerable interest from the scientific community to evaluate potential interrelationships between periodontitis and systemic pathologies such as Type 2 Diabetes Mellitus (T2DM, Type 2 Diabetes Mellitus). Studies focusing on genetic polymorphisms are essential mainly for the understanding they play in modulating the host's response to the action of periodontopathogenic microorganisms. The Interleukin 17 Alpha (IL17A) gene, which encodes the proinflammatory cytokine commonly referred to as IL-17, is produced by a subset of Th1 / Th0 helper T cells (T helper) and secreted by Th17 cells, involved in immune surveillance in mucous surfaces and involved in chronic inflammation. The aim of this study is to investigate three polymorphisms in the IL17A gene to assess whether they may be associated with genetic susceptibility to periodontitis in the presence (or not) of T2DM and to relate them to the patient's biochemical and clinical periodontal profile. Considering the sample size, patients with T2DM and severe or moderate periodontitis were investigated (Group T2DM_P, n = 199 patients); and for comparison of results, patients without T2DM with severe or moderate periodontitis (Group PERIODONTITIS, n = 342) were considered, and also patients without T2DM and periodontitis or slight periodontitis, that is, healthy patients (HEALTHY Group, n = 338), totaling 879 individuals. After a complete periodontal examination, each patient's mouthwash was obtained for DNA extraction using Ammonium Acetate. Three single nucleotide polymorphisms (SNP) in the IL17A gene were investigated using the TaqMan genotyping system using real-time PCR. A portion of the patients underwent biochemical examinations of the glycemic and lipid profile. After analyzing the frequencies of alleles and genotypes using the PLINK software, the Hardy-Weinberg Balance of each SNP was evaluated. The groups were compared among themselves, about allele and genotypic frequencies, performing multiple logistic regression analyses using the STATA program, adjusting to variables such as age, gender, smoking, and biochemical profile. As a result of the comparison between the HEALTHY group versus T2DM_P, multiple logistic regression, stratified for smoking, demonstrated that smoking patients with GG genotype for SNP rs3819024 of the IL17A gene were more likely to have periodontitis associated with T2DM (OR=6.60; IC 95%=1.31-33.01; p=0.02). A similar result was obtained for smoking patients in the PERIODONTITIS versus T2DM_P comparison, indicating an association between the GG genotype and T2DM (OR=5.05; IC 95%=1.36-18.82; p=0.01). Using the Plink software, the linkage disequilibrium between each SNP was verified, verifying that they were presented as haplotypes. The distribution of haplotypes was compared between groups by multiple logistic regression demonstrating that individuals with the rarest set of haplotypes (<3%) were more susceptible to Periodontitis together with T2DM (OR=2.30; IC95%=1.16-4.55, p=0.01), as well as T2DM alone (OR=2.98; IC95%=1.62-5.48, p=0.00). In conclusion from the results obtained with smokers and ex-smokers that the SNP rs3819024 of the IL17A gene shows an association with type 2 diabetes mellitus alone, and also as a comorbidity of periodontitis, however, the wide confidence interval observed indicates that such a result needs to be proven in a larger population. The association of the rare haplotypes with the studied pathologies can be a biologically spurious result since it was obtained by the sum of the different rare haplotypes so that if one of them is considered alone, the association will certainly be lost, clarifying that the number of patients in each group who carry the rare haplotypes is less than the amount calculated to obtain the power of the study, which is normal.
Worldwide, evidence continues to be sought genetic susceptibility to periodontitis (P), because as genetic differences between different ethnicities tend to influence such susceptibility. Also, there is considerable interest from the scientific community to evaluate potential interrelationships between periodontitis and systemic pathologies such as Type 2 Diabetes Mellitus (T2DM, Type 2 Diabetes Mellitus). Studies focusing on genetic polymorphisms are essential mainly for the understanding they play in modulating the host's response to the action of periodontopathogenic microorganisms. The Interleukin 17 Alpha (IL17A) gene, which encodes the proinflammatory cytokine commonly referred to as IL-17, is produced by a subset of Th1 / Th0 helper T cells (T helper) and secreted by Th17 cells, involved in immune surveillance in mucous surfaces and involved in chronic inflammation. The aim of this study is to investigate three polymorphisms in the IL17A gene to assess whether they may be associated with genetic susceptibility to periodontitis in the presence (or not) of T2DM and to relate them to the patient's biochemical and clinical periodontal profile. Considering the sample size, patients with T2DM and severe or moderate periodontitis were investigated (Group T2DM_P, n = 199 patients); and for comparison of results, patients without T2DM with severe or moderate periodontitis (Group PERIODONTITIS, n = 342) were considered, and also patients without T2DM and periodontitis or slight periodontitis, that is, healthy patients (HEALTHY Group, n = 338), totaling 879 individuals. After a complete periodontal examination, each patient's mouthwash was obtained for DNA extraction using Ammonium Acetate. Three single nucleotide polymorphisms (SNP) in the IL17A gene were investigated using the TaqMan genotyping system using real-time PCR. A portion of the patients underwent biochemical examinations of the glycemic and lipid profile. After analyzing the frequencies of alleles and genotypes using the PLINK software, the Hardy-Weinberg Balance of each SNP was evaluated. The groups were compared among themselves, about allele and genotypic frequencies, performing multiple logistic regression analyses using the STATA program, adjusting to variables such as age, gender, smoking, and biochemical profile. As a result of the comparison between the HEALTHY group versus T2DM_P, multiple logistic regression, stratified for smoking, demonstrated that smoking patients with GG genotype for SNP rs3819024 of the IL17A gene were more likely to have periodontitis associated with T2DM (OR=6.60; IC 95%=1.31-33.01; p=0.02). A similar result was obtained for smoking patients in the PERIODONTITIS versus T2DM_P comparison, indicating an association between the GG genotype and T2DM (OR=5.05; IC 95%=1.36-18.82; p=0.01). Using the Plink software, the linkage disequilibrium between each SNP was verified, verifying that they were presented as haplotypes. The distribution of haplotypes was compared between groups by multiple logistic regression demonstrating that individuals with the rarest set of haplotypes (<3%) were more susceptible to Periodontitis together with T2DM (OR=2.30; IC95%=1.16-4.55, p=0.01), as well as T2DM alone (OR=2.98; IC95%=1.62-5.48, p=0.00). In conclusion from the results obtained with smokers and ex-smokers that the SNP rs3819024 of the IL17A gene shows an association with type 2 diabetes mellitus alone, and also as a comorbidity of periodontitis, however, the wide confidence interval observed indicates that such a result needs to be proven in a larger population. The association of the rare haplotypes with the studied pathologies can be a biologically spurious result since it was obtained by the sum of the different rare haplotypes so that if one of them is considered alone, the association will certainly be lost, clarifying that the number of patients in each group who carry the rare haplotypes is less than the amount calculated to obtain the power of the study, which is normal.
Descrição
Palavras-chave
Polimorfismos genéticos, Diabetes Mellitus, Periodontite, Interleucina 17, Genetic Polymorphisms, Diabetes Mellitus, Periodontitis, Interleukin 17