title: Association of the IL-1RN2 allele with periodontal diseases.
abstract: OBJECTIVE
  Interleukin-1 receptor antagonist (IL-1Ra) gene (IL-1RN) polymorphism is associated with disease susceptibility and activity in several inflammatory diseases. The aim of this study was to investigate IL-1RN genotype and its associations with different periodontal diseases in a group of Turkish subjects.
  
  
  METHODS
  A total of 293 subjects were included in this study. Genomic DNA was obtained from the peripheral blood of 52 patients with generalized aggressive periodontitis (G-AgP), 51 with chronic periodontitis (CP) and 190 reference subjects. A variable number tandem repeat (VNTR) polymorphism in the second intron of the IL-1RN gene was detected by PCR-based methods. Probing pocket depth, clinical attachment loss, plaque accumulation and bleeding on probing (BOP) were recorded. The data were analyzed by the chi(2) test, logistic regression and Mann-Whitney U test.
  
  
  RESULTS
  There were significant differences among the groups in the distribution of IL-1RN genotypes (P = 0.0001) and allele frequencies (P = 0.0001). The frequency of IL-1RN2 allele 2 positivity was higher in the AgP and CP group than the reference group [odds ratio (OR) 6.654, 95% CI: 3.023-16.648; OR 10.327, 95% CI: 4.758-22.412, respectively]. The percentage of sites with BOP was significantly higher in IL-1RN2+ compared to IL-1RN2- CP patients (P = 0.022).
  
  
  CONCLUSIONS
  These results suggest that IL-1RN2 allele positivity is associated with periodontal disease in a Turkish population.
authors.affiliation: Molecular Medicine Laboratory, Department of Pediatrics, School of Medicine, Ege University, Izmir, Turkey.
authors.forename: Afig
authors.initials: A
authors.lastname: Berdeli
authors.forename: Gülnur
authors.initials: G
authors.lastname: Emingil
authors.forename: Ali
authors.initials: A
authors.lastname: Gürkan
authors.forename: Gül
authors.initials: G
authors.lastname: Atilla
authors.forename: Timur
authors.initials: T
authors.lastname: Köse
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein / Q000235:genetics*; D008297:Male; D010510:Periodontal Diseases / Q000235:genetics*; D016133:Polymerase Chain Reaction; D014421:Turkey
chemical_list: D053590:Interleukin 1 Receptor Antagonist Protein