Análise dos polimorfismos do gene HLA-G e do padrão de citocinas Th1/Th2 em pacientes com periodontite crônica e agressiva

• Autor(a) principal: Mattuella, Letícia Grando
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: http://tede2.pucrs.br/tede2/handle/tede/5458
• topic: BIOLOGIA MOLECULAR; BIOLOGIA CELULAR; POLIMORFISMO GENÉTICO HUMANO; PERIODONTITE; CITOCINAS; CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

Periodontitis has a bacterial etiology associated with the presence of a susceptible host. Immunogenetics factors have been studied in an attempt to explain the more aggressive disease, to establish diagnosis and to determine a more reliable prognosis. The present study had as objectives to evaluate the HLA-G polymorphisms (14 bp insertion/deletion and C/G +3142) and the cytokines profile (Th1 and Th2) in patients with chronic periodontitis, aggressive periodontitis and healthy controls. In relation to the 14 bp polymorphism, in chronic periodontitis patients, it was observed a significant increase in homozygous frequency for the deletion allele, when compared to controls. This same group presented a higher frequency of this allele, which was marginally not significant. Furthermore, no significant difference was observed between aggressive periodontitis patients and controls in relationship to the polymorphisms of 14 bp and C/G +3142.When haplotypes were estimated, an increased frequency of the deletion/G and decreased of the insertion/G was observed in chronic periodontitis patients compared to controls, but with no statistical difference. When evaluating serum cytokines concentration (IL-2, IL-4, IL-5, IL-10, TNF-α and IFN-γ), although no statistical difference could be seen between groups, a tendency to lower levels of IL-5 and IL-10 in aggressive periodontitis group was observed. Our results suggest that having HLA-G homozygosis for the deletion allele, yields three more times chance to present chronic periodontitis (OR = 3.07, 95% CI: 1.24-7.87), inferring a susceptibility role of this polymorphism in the pathogenesis of this condition. Yet considering the cytokine profiles, the aggressive periodontitis patients presented a tendency towards the Th2 profile, suggesting a contribution to the development of this exacerbated manifestation of the disease