title: TNF-α gene promoter polymorphisms contribute to periodontitis susceptibility: evidence from 46 studies.
abstract: OBJECTIVE
  Tumour necrosis factor-alpha (TNF-α) plays a critical role in the pathogenesis of periodontal disease. TNF-α gene polymorphisms can influence the TNF-α production. Many studies have focused the association between TNF-α gene promoter polymorphisms and periodontitis risk, but these results are still controversial.
  
  
  METHODS
  A meta-analysis was performed to assess the effect of TNF-α -308G/A (rs1800629), -238G/A (rs361525) and -863C/A (rs1800630) polymorphisms on either chronic (CP) or aggressive periodontitis (AgP) risk. Odds ratios (ORs) along with their 95% confidence intervals (CIs) were calculated to assess the strength of the association. Forty-six studies involving 5186 cases and 6683 controls were retrieved and analyzed.
  
  
  RESULTS
  The TNF-α -308G/A AA genotype was associated with increased CP risk in Asians, non-smoking Asians and Caucasians, and this polymorphism was significantly associated with elevated risk of AgP in Asians and Caucasians. Asian individuals carrying AA genotype had a significantly increased risk for -863C/A. No significant association was identified between TNF -238G/A polymorphism and CP.
  
  
  CONCLUSIONS
  These findings supported that TNF-α -308G/A and -863C/A polymorphisms may contribute to the susceptibility of periodontitis.
authors.affiliation: Department of Stomatology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Ding
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Ji
authors.forename: Xing
authors.initials: X
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Liangjun
authors.initials: L
authors.lastname: Zhong
mesh_terms: D000225:Adenine; D003596:Cytosine; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006147:Guanine; D006801:Humans; D010518:Periodontitis / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha; D006147:Guanine; D003596:Cytosine; D000225:Adenine
keywords: TNF-α; meta-analysis; periodontitis; polymorphism; susceptibility