title: Association between CCR6 and rheumatoid arthritis: a meta-analysis.
abstract: OBJECTIVE
  Chemokine (C-C motif) receptor 6 gene (CCR6) polymorphism has been reported to be associated with rheumatoid arthritis (RA) in different ethnic populations. Moreover, its inhibition by monoclonal antibody in mouse model has suppressed arthritis. However, few replication studies have reported conflicting results about this association. Therefore, to establish that CCR6 indeed is a risk factor associated with RA among different ethnic populations, a comprehensive meta-analysis study was conducted.
  
  
  METHODS
  PubMed and MEDLINE databases were searched using the term 'CCR6' for all articles published before May 2014. All the replication studies examining the association between CCR6 and RA were reviewed for meta-analysis. Data were summarized using random-effects meta-analysis. The heterogeneity and publication bias among studies were examined by χ(2) -based Q statistic test and Egger's test, respectively.
  
  
  RESULTS
  A total of 24955 RA patients and 56129 controls from seven articles were included in the meta-analysis. While CCR6 was a risk factor in Asian (OR = 1.19, 95% CI: 1.14-1.24) and European (OR = 1.14, 95% CI: 1.08-1.21) populations, it was indicated as a protective factor in African Americans (OR = 0.79, 95% CI: 0.62-0.96).
  
  
  CONCLUSIONS
  Our meta-analysis study concludes that there is a significant association between CCR6 and RA in all racial groups except African-American subgroup, which require a large sample size for concrete prediction.
authors.affiliation: Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, P. R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Cheng
authors.affiliation: Department of Nephrology, Tongji Hospital, Tongji Medical College, Huazhong University of Science And Technology Wuhan 430030, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, P. R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, P. R. China.
authors.forename: Weikai
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, P. R. China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, P. R. China.
authors.forename: Fengjing
authors.initials: F
authors.lastname: Guo
authors.affiliation: Department of Orthopedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology Wuhan 430030, P. R. China.
authors.forename: Anmin
authors.initials: A
authors.lastname: Chen
keywords: CCR6; Rheumatoid arthritis; meta-analysis; population genetics; susceptibility