Interferon-γ +874A/T polymorphism in relation to generalized chronic periodontitis and the presence of periodontopathic bacteria

BackgroundInterferon gamma (IFN-γ) is one of the key regulatory cytokines that has a significant effect on immune responses. It may be important in the chronic inflammatory diseases such as periodontitis in which increased IFN-γ levels were found. The aim of this study was to analyze +874A/T polymorphism in the IFN-γ gene and its associations with the presence of periodontopathic bacteria and susceptibility to generalized chronic periodontitis (CP).MethodsA total of 498 unrelated Czech white subjects were included in the present study. Genomic DNA was obtained from the peripheral blood of 244 patients with CP and 254 healthy subjects. The IFN-γ +874A/T polymorphism was determined by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Subgingival bacterial colonization (A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. forsythia, T. denticola, P. micros, F. nucleatum in subgingival pockets) was investigated by the DNA-microarray based periodontal pathogen detection kit in a subgroup of subjects (N = 110).ResultsOur results showed no differences in the allele and genotype frequencies of the IFN-γ +874A/T polymorphism between patients with CP and controls (P > 0.05). Although we found significant differences in the occurrence of periodontal bacteria between patients with CP and healthy controls (from P < 0.00001 to P < 0.05), no significant association between IFN-γ +874A/T polymorphism and periodontal pathogens was observed in any group.ConclusionsIn conclusion, these findings indicate that putative functional variant in the IFN-γ is not associated with susceptibility to chronic periodontitis or microbial composition in the Czech population.