This study is the first, to our knowledge, suggesting that the -572 G/C polymorphism of the IL-6 gene may be one of the protective factors associated with lower susceptibility to chronic periodontitis.

Our data suggest that combined genotypes composed of the TNF-alpha and LT-alpha gene polymorphisms may influence the susceptibility to chronic periodontitis. We also showed that, comparing the two genes, the 1/1 genotype of the NcoI polymorphism in the first intron of the LT-alpha gene is a more informative marker and it may be one of the protective genetic factors against chronic periodontitis in our population.

These findings suggest that genetic polymorphisms of the MMP-9 gene are not associated with the susceptibility to CP in the Czech population; however, the promoter variant may influence the severity of the disease in men.

Objectives. Periodontitis is an inflammatory disease characterized by connective tissue loss and alveolar bone destruction. Interleukin-8 (IL8) is important in the regulation of the immune response. The aim of this study was to analyze four polymorphisms in the IL8 gene in relation to chronic (CP) and aggressive (AgP) periodontitis. Methods. A total of 492 unrelated subjects were included in this case-control association study. Genomic DNA of 278 patients with CP, 58 patients with AgP, and 156 controls were genotyped, using the 5′ nuclease TaqMan assay, for IL8 (rs4073, rs2227307, rs2227306, and rs2227532) gene polymorphisms. Subgingival bacterial colonization was investigated by the DNA-microarray detection kit in a subgroup of subjects (N = 247). Results. Allele and genotype frequencies of all investigated IL8 polymorphisms were not significantly different between the subjects with CP and/or AgP and controls (P > 0.05). Nevertheless, the A(−251)/T(+396)/T(+781) and T(−251)/G(+396)/C(+781) haplotypes were significantly less frequent in patients with CP (2.0% versus 5.1%, P < 0.02, OR = 0.34, 95% CI: 0.15–0.78, resp., 2.0% versus 4.5%, P < 0.05, OR = 0.41, 95% CI: 0.18–0.97) than in controls. Conclusions. Although none of the investigated SNPs in the IL8 gene was individually associated with periodontitis, some haplotypes can be protective against CP in the Czech population.

These data indicate that the mentioned polymorphisms of the TGF-beta 1 gene do not influence susceptibility to adult periodontitis. There was no association between any polymorphisms in the TGF-beta 1 gene, severity of periodontitis and the smoking status in our study.