Abstract

Background: Cytokine IL18, also known as IFN-inducing factor, is an important regulator of innate and acquired immune
responses and plays a number of roles in chronic inflammation and dysfunction autoimmune disorder. Several
polymorphisms in the IL18 promoter region have been identified. As there is little evidence for IL18 polymorphisms and
periodontitis, this study aimed to evaluate the genetic association of polymorphisms of the IL18 gene (rs1946518).
Materials and Methods: A total of 100 subjects were recruited for this study, including 50 patients with periodontitis
(stage II, III and grade B) and 50 patients with healthy gingiva clinically intact periodontium. Genomic DNA was extracted
from the blood obtained from the subjects. DNA was amplified using primers specific to the MseI region of the IL18 receptor
gene. Amplicon was further genotyped using the restriction fragment length using the BtgI enzyme. Genotyping obtained
on the basis of the RFLP model was recorded and used for statistical analysis. The distributions of genotypes and allele
frequencies in the periodontal disease group and the control group were compared using the Chi Square test. Risks
associated with individual alleles or genotypes were calculated using odds ratios (ORs) with 95% confidence intervals.
Statistical significance in all trials was determined at p

Key words: Alleles, periodontitis, polymorphism, IL- 18 receptor