title: Cytotoxic T-lymphocyte antigen 4 gene +49A/G polymorphism significantly associated with susceptibility to primary biliary cirrhosis: a meta-analysis.
abstract: OBJECTIVE
  To evaluate comprehensively the association of cytotoxic T-lymphocyte antigen 4 (CTLA-4) +49A/G polymorphism with susceptibility to primary biliary cirrhosis (PBC).
  
  
  METHODS
  PubMed was used to search for the relevant published articles. The risk of PBC association with the CTLA-4+49A/G polymorphism was estimated for each study in a random-effects model. Odds ratio (OR) and 95% confidence interval (CI) were estimated for each study. Risks to PBC were estimated by stratified analysis in patients with different ethnicity and antimitochondrial antibody (AMA) status, as well as histological stages.
  
  
  RESULTS
  A total of 12 articles were included in the study. An association between PBC and CTLA-4 G allele was found, overall OR = 1.20, 95% CI 1.03-1.41 (P = 0.02). However, stratification by ethnicity indicated a significant association between the G allele and PBC in Asians (OR = 1.36, 95% CI 1.12-1.65, P = 0.002), but not in Caucasians (OR = 1.15, 95% CI 0.95-1.39, P = 0.15). Moreover, AMA positive patients carrying G allele were more susceptible to PBC compared with AMA negative patients (OR = 1.23, 95% CI 1.06-1.43, P = 0.007; OR = 0.98, 95% CI 0.71-1.34, P = 0.88, respectively).
  
  
  CONCLUSIONS
  Polymorphism in exon 1 of CTLA-4 gene at position 49 may act as a candidate of susceptibility locus to PBC. However, larger studies with participants of varying ethnicity and stratified by clinical and laboratory characteristics are needed to validate our findings.
authors: Institute of Digestive Diseases, Xijing Hospital, State Key Laboratory of Cancer Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China.
authors: Rui Rui
authors: RR
authors: Chen
authors: Zhe Yi
authors: ZY
authors: Han
authors: Jin Ge
authors: JG
authors: Li
authors: Yong Quan
authors: YQ
authors: Shi
authors: Xin Min
authors: XM
authors: Zhou
authors: Jing Bo
authors: JB
authors: Wang
authors: Xi Qiang
authors: XQ
authors: Cai
authors: Xue Chang
authors: XC
authors: Wang
authors: Ying
authors: Y
authors: Han
authors: Dai Ming
authors: DM
authors: Fan
mesh_terms: D000483:Alleles; D044466:Asian People / Q000208:ethnology / Q000235:genetics; D060908:CTLA-4 Antigen / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006801:Humans; D008105:Liver Cirrhosis, Biliary / Q000208:ethnology / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012307:Risk Factors; D044465:White People / Q000208:ethnology / Q000235:genetics
chemical_list: D060908:CTLA-4 Antigen