title: Lack of association of TNF-alpha promoter polymorphisms with ankylosing spondylitis: a meta-analysis.
abstract: OBJECTIVE
  Genetic factors, in addition to the HLA-B27, could play a role in the pathogenesis of AS. TNF-alpha promoter polymorphisms have been reported to be associated with AS susceptibility, but the results of these previous studies have been inconsistent. The aim of this study was to explore whether TNF-alpha promoter polymorphisms confer susceptibility to AS.
  
  
  METHODS
  We conducted a random effect meta-analysis on the association of the A/A genotype (the recessive effect), the A/A + A/G genotype (the dominant effect) and the A allele of the TNF-alpha -308 and -238 polymorphisms with AS.
  
  
  RESULTS
  Eight studies, consisting of seven European studies and one Latin American study, were included in this meta-analysis. Any association between AS and the TNF-alpha -308 A allele was not found [odds ratio (OR) = 0.911; 95% CI 0.512, 1.286; P = 0.636; I(2) = 73.8]. There was also no association of the TNF-alpha -308 AA and AA+AG genotypes with AS. Meta-analysis of the TNF-alpha -238 polymorphisms showed no association with AS (OR for A allele = 0.930; 95% CI 0.498, 1.737; P = 0.821; I(2) = 71.6). Subgroup analysis by ethnicity and HLA-B27 positivity did not change the results for the association of the TNF-alpha -308 and -238 polymorphisms with AS.
  
  
  CONCLUSIONS
  This meta-analysis including 2247 subjects has shown that there is a lack of association of the TNF-alpha -308 A/G and -238 A/G polymorphisms with AS.
authors.affiliation: Department of Internal Medicine, Division of Rheumatology, Korea University Anam Hospital, Korea University College of Medicine, 126-1 5-ga, Anam-dong, Seongbuk-gu, Seoul 136-705, Korea. lyhcgh@korea.ac.kr
authors.forename: Young H
authors.initials: YH
authors.lastname: Lee
authors.forename: Gwan G
authors.initials: GG
authors.lastname: Song
mesh_terms: D020022:Genetic Predisposition to Disease; D006801:Humans; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics; D017594:Publication Bias; D013167:Spondylitis, Ankylosing / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha