Association between CCR6 and rheumatoid arthritis: A meta-analysis

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 χ2 -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.