Isfahan University of Medical SciencesDental Research Journal1735-33279420121025Evaluation of IL-8 gene polymorphisms in patients with periodontitis in Hamedan, Iran492492ENBehzadHoushmandMehrdadHajilooiAlirezaRafieiMohsenBidgoliSaraSoheilifarPeriodontology, Dental Research Center, School of Dentistry, Hamedan University of Medical Sciences, Hamedan, Iran. sara_soheilifar@yahoo.com20110616Background: Many environmental and genetic factors are known as factors that increase the susceptibility to periodontitis. As IL-8 is a chemokine that mediate the inflammatory process in periodontal disease, we decided to evaluate the effect of its polymorphism on chronic and aggressive periodontitis. Materials and Methods: In this cross-sectional study DNA was isolated from the whole blood of 107 periodontitis patients and 199 healthy individuals. All samples were genotyped for the IL-8 polymorphisms using the polymerase chain reaction with sequence specific primers. The distribution of the interleukin-8 genotype and allele frequencies in control and disease groups was analyzed by the Chi-square test and a P-value of < 0.05 was considered statistically significant. Results: The findings revealed that the allele and genotype frequencies of A2767T, T11722T2, and C781T polymorphism of IL-8 gene were not significantly differed between controls and patients. However, there was a significant difference in the genotype frequencies of IL-8 A251T (P < 0.0001), G396T (P < 0.0001), and C1633T (P < 0.0001) gene polymorphism between the patient and the control groups. Additionally, there was a significant difference in the genotype frequencies of C1633T (P < 0.05) polymorphism of IL-8 gene between the aggressive and chronic periodontitis. Conclusion: IL-8 gene polymorphism may be protective against periodontitis. Key Words: Aggressive periodontitis, chronic periodontitis, genetic polymorphism, interleukin-8