BACKGROUND: Findings regarding the associations between the CC motif chemokine ligand 5 (CCL5) -403G/A and -28C/G polymorphisms and asthma risk are controversial.We performed a meta-analysis to determine whether CCL5 polymorphisms are associated with asthma risk. METHODS: We searched the Pubmed, Embase, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases for studies published before June 2013. The strength of associations was calculated using ORs with 95% CIs. RESULTS: Twenty case-control studies were included in this meta-analysis. We did not observe a significant association between the CCL5 -403G/A polymorphism and asthma risk (OR, 1.10; 95% CI, 0.93-1.30; P = .25). The CCL5 - 28C/G polymorphism, however, was associated with a significantly elevated asthma risk (OR, 1.17; 95% CI, 1.02-1.33; P = .02). Subgroup analyses found that the CCL5 -28C/G polymorphism was significantly associated with asthma risk in Asians (OR, 1.16; 95% CI, 1.01-1.33; P = .04) and children (OR, 1.29; 95% CI, 1.03-1.63; P = .03). CONCLUSIONS: This meta-analysis suggests that the CCL5 -28C/G polymorphism is a risk factor for asthma.
BACKGROUND: Findings regarding the associations between the CC motif chemokine ligand 5 (CCL5) -403G/A and -28C/G polymorphisms and asthma risk are controversial.We performed a meta-analysis to determine whether CCL5 polymorphisms are associated with asthma risk. METHODS: We searched the Pubmed, Embase, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases for studies published before June 2013. The strength of associations was calculated using ORs with 95% CIs. RESULTS: Twenty case-control studies were included in this meta-analysis. We did not observe a significant association between the CCL5-403G/A polymorphism and asthma risk (OR, 1.10; 95% CI, 0.93-1.30; P = .25). The CCL5- 28C/G polymorphism, however, was associated with a significantly elevated asthma risk (OR, 1.17; 95% CI, 1.02-1.33; P = .02). Subgroup analyses found that the CCL5-28C/G polymorphism was significantly associated with asthma risk in Asians (OR, 1.16; 95% CI, 1.01-1.33; P = .04) and children (OR, 1.29; 95% CI, 1.03-1.63; P = .03). CONCLUSIONS: This meta-analysis suggests that the CCL5-28C/G polymorphism is a risk factor for asthma.