title: Association between CTLA-4 exon-1 +49A>G polymorphism and primary biliary cirrhosis risk: a meta-analysis.
abstract: OBJECTIVE
  CTLA-4 exon-1 +49A>G polymorphisms have been reported to influence the risk for primary biliary cirrhosis in many studies; however, the results still remain controversial and ambiguous. The aim of this study was to determine more precise estimations for the relationship between CTLA-4 exon-1 +49A>G polymorphisms and the risk for primary biliary cirrhosis.
  
  
  METHODS
  Electronic searches for all publications were conducted on associations between this variant and breast cancer in several databases through November 2010. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of the association. Eight studies were identified including 2151 cases and 2214 controls.
  
  
  RESULTS
  Overall, there were no significant associations between CTLA +49G>A polymorphism and primary biliary cirrhosis risk (codominant model: GA vs. AA OR=1.190, 95% CI=0.818-1.732; GG vs. AA OR=1.153, 95% CI=0.858-1.550; dominant model: OR=1.181, 95% CI=0.873-1.599; and recessive model: OR=1.148; 95% CI=0.903-1.459). In the subgroup analysis by ethnicity, a significantly increased risk was found for Asians (GG vs. AA OR=1.873; 95% CI=1.202-2.921) and recessive model (OR=1.758; 95% CI = 1.271-2.433). In the stratified analysis by control sources, significant association were observed in population-based studies (GA vs. AA OR=1.432; 95% CI=1.078-1.902).
  
  
  CONCLUSIONS
  This meta-analysis suggests that the CTLA-4 +49G>A polymorphism may be a risk factor for primary biliary cirrhosis in Asians.
authors: Department of Hepato-Biliary Surgery, Anhui Provincial Hospital Affiliated with Anhui Medical University, Anhui, China. tagsmile1985@163.com
authors: Qiang
authors: Q
authors: Huang
authors: Feng
authors: F
authors: Shao
authors: Cheng
authors: C
authors: Wang
authors: Lu-jun
authors: LJ
authors: Qiu
authors: Yuan-guo
authors: YG
authors: Hu
authors: Ji-hai
authors: JH
authors: Yu
mesh_terms: D015703:Antigens, CD / Q000235:genetics*; D060908:CTLA-4 Antigen; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008105:Liver Cirrhosis, Biliary / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors
chemical_list: D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human