title: Polymorphisms of the interleukin-18 gene in periodontitis patients.
abstract: BACKGROUND
  Interleukin (IL)-18 regulates the expression of the proinflammatory cytokine interferon (IFN)-gamma. The present study sought to test the putative involvement of six different IL-18 gene polymorphisms in pre-disposition to destructive periodontal disease.
  
  
  METHODS
  A total of 123 patients with periodontitis and 121 healthy controls were genotyped for six IL-18 polymorphisms at position -656, -607, -137, +113, +127 and codon 35/3. Genotyping has been performed by PCR and restriction fragment length polymorphism analysis. The frequencies of alleles and genotypes as well of haplotypes within both study groups were compared using the Pearson Chi-square test at a level of significance of 5% (p<0.05).
  
  
  RESULTS
  Coseggregation was found to be 100% for the two polymorphisms at position -656 and -607 as well as for the polymorphisms at position -137, +113, and +127. The distribution of genotypes for the IL-18 gene polymorphism at position -656/-607 (p=0.854), at position -137/+113/+127 (p=0.320), and at codon 35/3 (p=0.481) was not significantly different among periodontitis patients if compared with healthy control subjects. The distribution of haplotype combinations for the -607 and -137 polymorphism also showed not significant difference between the both study groups (p=0.545).
  
  
  CONCLUSIONS
  Herein the six different IL-18 gene polymorphisms were not associated with destructive periodontal disease.
authors.affiliation: Poliklinik für Zahnerhaltung und Parodontologie, Standort Innenstadt, München, Germany. mfolwa@dent.med.uni-muenchen.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Folwaczny
authors.forename: Jürgen
authors.initials: J
authors.lastname: Glas
authors.forename: Helga-Paula
authors.initials: HP
authors.lastname: Török
authors.forename: Laurian
authors.initials: L
authors.lastname: Tonenchi
authors.forename: Ekaterini
authors.initials: E
authors.lastname: Paschos
authors.forename: Bernhard
authors.initials: B
authors.lastname: Bauer
authors.forename: Olga
authors.initials: O
authors.lastname: Limbersky
authors.forename: Christian
authors.initials: C
authors.lastname: Folwaczny
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006239:Haplotypes; D006801:Humans; D020382:Interleukin-18 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000235:genetics* / Q000276:immunology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide
chemical_list: D020382:Interleukin-18