title: Analysis of the interleukin-6 gene promoter polymorphisms in Czech patients with chronic periodontitis.
abstract: BACKGROUND
  Chronic periodontitis is an inflammatory disease, which is a major cause of tooth loss. The proinflammatory cytokines interleukin-1 (IL-1) and interleukin-6 (IL-6) are key regulators of the host response to microbial infection and major modulators of extracellular matrix catabolism and bone resorption. The purpose of this study was to investigate the associations of chronic periodontitis with IL-6 gene polymorphisms (at positions -597 [G/A], -572 [G/C], and -174 [G/C]).
  
  
  METHODS
  We analyzed allele, genotype, and haplotype distributions of the IL-6 promoter variants in a case-control study involving 148 patients with chronic periodontitis and 107 unrelated controls.
  
  
  RESULTS
  Our results showed significant differences in the distributions of alleles and genotypes of the IL-6 (-572 G/C) polymorphism between patients and the control population (chi2 = 10.393, P= 0.001, P(corr) < 0.01). The difference was due to the underrepresentation of the -572 G/C heterozygotes in patients (6.1%) compared to controls (19.6%). Although no variant "CC" homozygotes were detected in our cases and controls, heterozygosity protected against chronic periodontitis, representing a 73% reduction of risk (odds ratio [OR] = 0.27, 95% confidence interval: 0.12-0.61) compared to wild-type homozygotes. However, there were no significant differences in genotype or allele frequencies between both groups for IL-6 -597 G/A and -174 G/C polymorphisms.
  
  
  CONCLUSIONS
  This study is the first, to our knowledge, suggesting that the -572 G/C polymorphism of the IL-6 gene may be one of the protective factors associated with lower susceptibility to chronic periodontitis.
authors.affiliation: Department of Pathological Physiology, Medical Faculty, Masaryk University, Brno, Czech Republic. holla@med.muni.cz
authors.forename: Lydie Izakovicova
authors.initials: LI
authors.lastname: Holla
authors.forename: Antonin
authors.initials: A
authors.lastname: Fassmann
authors.forename: Andrea
authors.initials: A
authors.lastname: Stejskalová
authors.forename: Vladimír
authors.initials: V
authors.lastname: Znojil
authors.forename: Jiri
authors.initials: J
authors.lastname: Vanĕk
authors.forename: Jiri
authors.initials: J
authors.lastname: Vacha
mesh_terms: D000328:Adult; D000483:Alleles; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009010:Monte Carlo Method; D016017:Odds Ratio; D010518:Periodontitis / Q000235:genetics* / Q000276:immunology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011401:Promoter Regions, Genetic / Q000235:genetics; D012907:Smoking
chemical_list: D015850:Interleukin-6