title: Interleukin-6 gene -174G/C polymorphism and bronchial asthma risk: a meta-analysis.
abstract: The Interleukin-6 (IL-6) genetic polymorphism is associated with bronchial asthma, a number of studies have been conducted to investigate the association between IL-6 gene -174G/C polymorphism and bronchial asthma risk. However, the results are inconclusive. This meta-analysis aims to investigate whether -174G/C polymorphism is a potential risk factor for bronchial asthma. We searched Web of Science, PubMed, Google Scholar, China National Knowledge Infrastructure (CNKI) and Wanfang Database from inception through December 1st, 2014. Meta-analysis was performed using the STATA 12.0. Overall, a significantly reduced risk for asthma was found in IL-6 -174 CC genotype (CC vs. GG: OR = 0. 51, 95% CI = 0.27-0.96, P = 0.038). Furthermore, analysis by ethnicity indicated that there was a markedly reduced risk for asthma in IL-6 -174 CC genotype in Caucasian (CC vs. GG: OR = 0.51, 95% CI = 0.27-0.96, P = 0.038). Analysis by age indicated that there was a significantly reduced risk for asthma in IL-6 -174 CC genotype in adults (CC vs. GG: OR = 0.47, 95% CI = 0.23-0.97, P = 0.042). In conclusion, the current meta-analysis indicates that IL-6 -174 CC genotype may be a protective factor against asthma in Caucasian and adults.
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University Xi'an, China.
authors.forename: Fangwei
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University Xi'an, China.
authors.forename: Xinming
authors.initials: X
authors.lastname: Xie
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University Xi'an, China.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University Xi'an, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Ke
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University Xi'an, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University Xi'an, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Medical College, Xi'an Jiaotong University Xi'an, China.
authors.forename: Manxiang
authors.initials: M
authors.lastname: Li
keywords: IL-6; asthma; meta-analysis; polymorphism; risk