Analysis of Toll-Like Receptor-4 Genes Polymorphism and Il-18 in Severe Chronic Periodontitis Fadhil Raghad1,*, AL-Ghaban Nada M.H.1, Ghurabi Batool Hassan Al1 1Department of Periodontics, College of Dentistry, University of Baghdad, Iraq *Correspondence author: Raghad Fadhil, E-mail: raghadfadhil@codental.uobaghdad.edu.iq
Online published on 30 April, 2019. Abstract A number of genetic polymorphisms have been associated with risk for periodontal disease in various populations. The genes encoding toll like receptor-4 (TLR-4) may affect susceptibility to and/or severity of periodontitis. Several studies have shown that the levels of interleukin-18 (IL-18) in patients with periodontitis differ from those in healthy subjects. IL-18 is synthesized intracellularly after TLR4 is activated by lipopolysaccharides. A case control approach used to explore the correlation between polymorphisms in TLR4 and the degree of susceptibility and severity of chronic periodontitis, also exploring the impact of TLR4 polymorphism on circulating cytokines IL-18 in chronic periodontitis patients. Ninety six Iraqi subjects (69 males and 27 females) their age range (30–50) years were included in study divided in to two groups (patients with severe chronic periodontitis and healthy control) venous blood were collected from each patients for immunologic analysis of IL-18 and genetic analysis of TLR-4. Analytic statistics for serum IL-18 between chronic periodontitis and control groups showed significant decrease in the medium of IL-18 in chronic periodontitis group compared to control group. Furthermore, two single nucleotide polymorphisms (SNPs) were detected in TLR-4 according to primer design located at rs 4986790 and rs 4986791, with non-significant association of both SNPs with chronic periodontitis patients although both SNP were strongly correlated with the amount of dental plaque. Genetic polymorphisms in TLR-4 were not associated with the susceptibility of periodontitis in Iraqi patients. However, they might have an association with the clinical parameters and can modify severity of the disease. High frequencies of TLR-4 at rs4986790 in control group suggest that these alleles may confer protective effects against the disease or a low, weak susceptibility to periodontal disease. Top Keywords Toll like receptor-4, IL-18, severe chronic periodontitis, gene polymorphisms. Top |