title: Association between cytotoxic T-lymphocyte-associated antigen 4 +49A/G polymorphism and persistent hepatitis B virus infection in the Asian population: evidence from the current studies.
abstract: OBJECTIVE
  A number of studies assessed the association between cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) +49A/G polymorphism and persistent hepatitis B virus (HBV) infection risk. However, the results are quite contradictory. In order to obtain a more precise estimation of the relationship, a meta-analysis was performed.
  
  
  METHODS
  Pubmed, ISI Web of Knowledge, HuGE Navigator, Wanfang Database, and China National Knowledge Infrastructure were searched. Crude odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated to estimate the strength of this association.
  
  
  RESULTS
  Six publications were included in the final meta-analysis with 1075 cases and 1321 controls for CTLA-4 +49A/G polymorphism according to our inclusion and exclusion criteria. We observed that the CTLA-4 +49A/G polymorphism was significantly correlated with chronic HBV infection risk (the homozygote codominant model: OR 1.67, 95% CI 1.30-2.15; the dominant model: OR 1.34, 95% CI 1.01-1.78; the recessive model: OR 1.56, 95% CI 1.24-1.96; the allele contrast model: OR 1.32, 95% CI 1.10-1.59). No publication bias was observed in this study according to Begg's funnel plot and Egger's test.
  
  
  CONCLUSIONS
  CTLA-4 +49A/G polymorphism is assumed to confer a higher risk for persistent HBV infection in the Asian population.
authors.affiliation: Department of Infectious Diseases, Nanjing Drum Tower Hospital Clinical College of Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Huang
authors.forename: Yingying
authors.initials: Y
authors.lastname: Hao
authors.forename: Yaofu
authors.initials: Y
authors.lastname: Fan
authors.forename: Chenchen
authors.initials: C
authors.lastname: Yang
authors.forename: Kangkang
authors.initials: K
authors.lastname: Wu
authors.forename: Shufeng
authors.initials: S
authors.lastname: Cao
authors.forename: Chao
authors.initials: C
authors.lastname: Wu
mesh_terms: D001208:Asia / Q000453:epidemiology; D044466:Asian People; D060908:CTLA-4 Antigen / Q000235:genetics*; D030541:Databases, Genetic; D005260:Female; D006515:Hepatitis B virus; D019694:Hepatitis B, Chronic / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D008297:Male; D008957:Models, Genetic; D011110:Polymorphism, Genetic; D039781:PubMed; D012307:Risk Factors
chemical_list: D060908:CTLA-4 Antigen