title: Tumor necrosis factor-alpha-308A allele may have a protective effect for chronic hepatitis B virus infection in Mongoloid populations.
abstract: OBJECTIVE
  Previous studies on the tumor necrosis factor-alpha (TNF-alpha)-308 gene promoter polymorphism in chronic hepatitis B virus (HBV) infection have reported conflicting results.
  
  
  METHODS
  We carried out a meta-analysis of 21 studies in relation to the TNF-alpha-308 gene promoter, involving a total of 4230 chronic HBV infection cases and 2905 controls.
  
  
  RESULTS
  The overall meta-analysis indicated that -308A heterozygotes (GA) had a significant 27% decreased risk of developing chronic hepatitis B (CHB) (odds ratio (OR) 0.73; 95% confidence interval (CI) 0.57-0.93; p=0.012). For -308A allele homozygotes (AA) and carriers (GA+AA), the pooled odd ratios both indicated a significantly decreased risk of CHB (OR 0.28; 95% CI 0.19-0.43; p=0.0001; and OR 0.70; 95% CI 0.55-0.89; p=0.004, respectively). In subgroup analyses by ethnicity, a significantly decreased risk was associated with -308 variant genotypes (GA and AA) in Mongoloid populations in all genetic models. However, no significant associations were found in Caucasoids. Moreover, in the subgroup analyses by control group, significantly decreased risk was associated with -308 variant genotypes (GA and AA) in the group of spontaneously recovered cases in all genetic models; however, no significant associations were found in the group of healthy cases.
  
  
  CONCLUSIONS
  The TNF-alpha-308A allele is a protective factor for chronic HBV infection, especially in Mongoloids.
authors.affiliation: Department of Infection and Liver Diseases, Liver Research Center, First Affiliated Hospital of Wenzhou Medical College, No. 2 Fuxue Lane, Wenzhou, Zhejiang, China. blueman1320@163.com
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Zheng
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: Qiu
authors.forename: Yong-Ning
authors.initials: YN
authors.lastname: Xin
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Pan
authors.forename: Ke-Qing
authors.initials: KQ
authors.lastname: Shi
authors.forename: Yong-Ping
authors.initials: YP
authors.lastname: Chen
mesh_terms: D000483:Alleles; D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D005787:Gene Frequency; D005838:Genotype; D006515:Hepatitis B virus / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000235:genetics* / Q000821:virology; D006801:Humans; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha