title: TLR4 and IL-18 gene variants in chronic periodontitis: impact on disease susceptibility and severity.
abstract: The aim of the study was to assess whether genotypes in the Toll-like receptor 4 gene and in the promoter of the interleukin-18 gene are associated with the susceptibility to chronic periodontitis. 108 chronic periodontitis patients and 76 controls were genotyped for c.896A>G/1196C>T (TLR4 gene) and for c.-368G>C/ c.-838C>A (IL-18 promoter). There were no significant differences in genotype and allele distributions between the study groups. Periodontitis severity in patients with TLR4 c.896AG/1196CT genotype was significantly higher than wildtype carriers. The percentage of teeth with clinical attachment loss > or = 5 mm was 77.3% and 58.8%, respectively (p < or = 0.006, t-test). All subjects were further classified into carriers and non-carriers of at least one variant of each gene. A logistic regression analysis adjusted for gender, smoking, and age showed no association between gene variant carrier status and periodontitis (OR = 1.98, 95% CI 0.61-6.39). The results did not show that IL-18 and TLR4 variants have an effect on the susceptibility to chronic periodontitis. Considering the low number of periodontitis patients carrying TLR4 variants (11%), a comparison of the periodontitis severity depending on the genotype has to be interpreted cautiously.
authors.affiliation: Department of Conservative Dentistry and Periodontology, Medical Faculty Carl Gustav Carus, TU Dresden, Dresden, Germany. Barbara.Noack@uniklinikum-dresden.de
authors.forename: Barbara
authors.initials: B
authors.lastname: Noack
authors.forename: Heike
authors.initials: H
authors.lastname: Görgens
authors.forename: Katrin
authors.initials: K
authors.lastname: Lorenz
authors.forename: Hans Konrad
authors.initials: HK
authors.lastname: Schackert
authors.forename: Thomas
authors.initials: T
authors.lastname: Hoffmann
mesh_terms: D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000235:genetics* / Q000473:pathology*; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D020382:Interleukin-18 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D051197:Toll-Like Receptor 4 / Q000235:genetics*
chemical_list: D020382:Interleukin-18; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4