Association of the-159 CD14 gene polymorphism and lack of association of the-308 TNFA and Q551R IL-4RA polymorphisms with severe chronic periodontitis in Swedish Caucasians

Background: Severe forms of periodontitis are suggested to have a genetic basis. Objective: The aim of the present investigation was to study the association of gene polymorphisms related to some immune regulation components (G-308A TNFA, Q551R IL-4RA and C-159T CD14) with severe chronic periodontitis. Materials and Methods: Sixty patients (aged 36-74 years; mean 54.5 +/- 8.5) with severe and generalized chronic periodontitis were included. The patients exhibited bone loss > 50% at all teeth. Thirty-nine periodontally healthy subjects between 35 and 78 years of age (mean 51.0 +/- 10.9) were recruited as controls. DNA was isolated from peripheral blood cells and genotyping was performed by combination of PCR and restriction endonuclease mapping. Results: While gene polymorphisms for TNFA and IL-4RA did not show any association with severe chronic periodontitis, the analysis of the -159 CD14 gene polymorphism revealed significant differences between test and control groups. The proportion of subjects that exhibited the TT genotype was significantly smaller in the group with severe periodontitis than in periodontal healthy group (p=0.028; Fisher's exact test). The C allele carriage was 90% in the periodontitis group and significantly higher than in the healthy control group (72%). Conclusion: It is suggested that the -159 CD14 gene polymorphism is associated with chronic periodontitis in Caucasian subjects of a north European origin.