title: Evaluation of IL-8 gene polymorphisms in patients with periodontitis in Hamedan, Iran.
abstract: BACKGROUND
  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.
  
  
  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, T(1)1722T(2), 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.
  
  
  CONCLUSIONS
  IL-8 gene polymorphism may be protective against periodontitis.
authors.affiliation: Department of Periodontology, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Behzad
authors.initials: B
authors.lastname: Houshmand
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hajilooi
authors.forename: Alireza
authors.initials: A
authors.lastname: Rafiei
authors.forename: Mohsen
authors.initials: M
authors.lastname: Bidgoli
authors.forename: Sara
authors.initials: S
authors.lastname: Soheilifar