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

Background: Interferon gamma (IFN-gamma) is one of the key regulatory cytoldnes that has a significant effect on immune responses. It may be important in the chronic inflammatory diseases such as periodontitis in which increased IFN-gamma levels were found. The aim of this study was to analyze +874A1T polymorphism in the IFN-gamma gene and its associations with the presence of periodontopathic bacteria and susceptibility to generalized chronic periodontitis (CP). Methods: A 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-gamma +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). Results: Our results showed no differences in the allele and genotype frequencies of the IFN-gamma +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-gamma +874A/T polymorphism and periodontal pathogens was observed in any group. Conclusions: In conclusion, these findings indicate that putative functional variant in the IFN-gamma is not associated with susceptibility to chronic periodontitis or microbial composition in the Czech population. (c) 2010 Elsevier Ltd. All rights reserved.