The ‐ A2518G polymorphism in the MCP‐1 gene and inflammatory bowel disease risk: A meta‐analysis

Objective The monocyte chemoattractant protein‐1 ( MCP‐1 ) ‐ A2518G gene polymorphism has been found to be involved in the susceptibility to inflammatory bowel disease ( IBD ); however, the results of existing studies are controversial. The aim of this meta‐analysis was to assess the relationship between the MCP‐1 ‐ A2518G polymorphism and the risk of IBD. Methods PubMed, EMBASE and MEDLINE were searched for studies assessing the relationship between the ‐ A2518G polymorphism in MCP‐1 gene and the risk of IBD . Available data were extracted and statistically analyzed using STATA 12.0. Results A total of five publications involving 3137 individuals (1818 IBD cases and 1319 controls) were included in the meta‐analysis. A combined analysis revealed that the MCP‐1 ‐ A2518G polymorphism in was a protective factor for GG + AG   vs   AA ( OR  0.76, 95% CI 0.67–0.87, P  = 0.000). Subgroup analysis by ethnicity showed that among E uropean patients the AG + GG homozygote, unlike the AA homozygote, had a protective effect against IBD ( OR 0.73, 95% CI 0.63–0.84, P  = 0.000), but did not do so among A sian and A frican patients. Subgroup analysis by disease subtype suggested the ‐ A2518G polymorphism in MCP‐1 had a protective effect against C rohn's disease ( OR  0.69, 95% CI 0.58–0.81, P  = 0.000), but not against ulcerative colitis. Conclusions Our meta‐analysis suggested that the ‐ A2518G polymorphism in MCP‐1 may be a protective factor for IBD in E uropean populations. Further studies are required to confirm these findings.