TLR4 and IL-18 Gene Variants in Chronic Periodontitis: Impact on Disease Susceptibility and Severity

• Published in: Immunological investigations Vol. 38; no. 3-4; pp. 297 - 310
• Main Authors: Noack, Barbara, Görgens, Heike, Lorenz, Katrin, Schackert, Hans Konrad, Hoffmann, Thomas
• Format: Journal Article
• Language: English
• Published: England Informa UK Ltd 2009; Taylor & Francis
• Subjects: Case-Control Studies; Chronic periodontitis; Chronic Periodontitis - genetics; Chronic Periodontitis - pathology; Female; Genetic Predisposition to Disease; Genetic risk; Genome-Wide Association Study; Genotype; Humans; IL-18 gene; Innate immune response; Interleukin-18 - genetics; Male; Middle Aged; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Promoter Regions, Genetic; TLR4 gene; Toll-Like Receptor 4 - genetics
• ISSN: 0882-0139; 1532-4311
• DOI: 10.1080/08820130902846290

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 ≥ 5 mm was 77.3% and 58.8%, respectively (p ≤ 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.