EVALUATION OF INTERLEUKIN-6, LYMPHOTOXIN-alpha AND TNF-alpha GENE POLYMORPHISMS IN CHRONIC PERIODONTITIS

Background: Periodontitis is a chronic inflammatory disruption of the periodontal supportive tissues. There are the numerous evidences for his bacterial etiology. Though the occurrence of periodontal bacteria is considered to be the main cause of periodontitis, certain characteristics of the individual immune response may also have inuuence on the disease development and progression, and on the treatment outcomes. There are some reports that attempt to identify genetic factors associated with periodontitis including polymorphisms of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) genes. We were interested from the distribution of several genotypes of the cytokines: interleukin-6 - (G-174C) and (G-597A), lymphotoxin-alpha (A+252G), and tumour necrosis factor-alpha (G-308A) in patients with chronic periodontitis. Aim: To investigate the association of chronic periodontitis with certain gene polymorphisms of interleukin-6 (IL-6), Lymphotoxin-alpha, and tumor necrosis factor-alpha (TNF-alpha). Material and methods: The study included 30 patients with moderate or severe chronic periodontitis, and 10 persons with healthy periodontium. Total genomic DNA was extracted from the buccal epithelial cells. TNF-A (G-308A), IL-6 (G-174C), IL-6 (G-597A) and LT-A (A+ 252G) genes polymorphisms were analyzed by Polymerase chain reaction (PCR). Results: Outcomes showed a large variety in genotype's distribution in the investigated groups. No important difference was observed in the distribution of IL-6, TNF-alpha and LT-a genotypes between chronic periodontitis patients and controls in this study be reason of the small studied group. However, a signicant difference in the LT-alpha was observed - a prevalence of the genotype GG in patients with severe periodontitis. In relation with IL-6 (G-597A) and IL6 (G-174C) genotyping - in both of them in patients with severe periodontitis was occurred most frequently the genotype GG. In patients with periodontitis the frequency of genotype GG of TNF-alpha (G-308A) was significantly increased. Conclusion: The assessment IL-6 (G-597A) and IL6 (G-174C), and TNF-alpha (G-308A) revealed that genotype GG was moderate associated with chronic periodontitis in Bulgarian individuals. As a result of these findings we may suppose that the G allele may play an important role in the development and progression of periodontal disease in this population. The frequency of LT-A (A252G) was significantly greater in severe periodontitis patients in this study.