Abstract: Objective  To explore the association of interleukin-18(IL-18) and monocyte chemoattractant protein-1(MCP-1) polymorphisms with rheumatoid arthritis (RA). Methods  The retrieval strategy and criteria for inclusion and exclusion were formulated, with which the following databases were searched, including PubMed, Web of Knowledge, WanFang Database, China Biology Medical Literature Database (CBM) and China National Knowledge Infrastructure (CNKI) from Jan. 1990 to Sept. 2013, to identify relevant papers addressing IL-18 or MCP-1 polymorphisms and risk of RA association without language preference. Combined OR values and 95%CI were calculated with Review Manager 5.0. Results  A total of 16 eligible studies were included in the meta-analysis, 12 of which (3527 cases and 3161 controls) were on IL-18-607A/C polymorphism, and 4 (1460 cases and 1303 controls) were on MCP-1-2518A/G polymorphism. Statistical analysis showed that IL-18-607CC genotype was associated with RA (OR=1.27, 95%CI=1.02-1.58). After literatures which did not conform with Hardy-Weinberg (HWE) were ruled out and stratified by race, it revealed that IL-18-607C allele was associated with RA in Asian population (OR=1.33, 95%CI=1.01-1.76). There was no significant association between MCP-1-2518A/G polymorphism and RA. Conclusion  This meta-analysis indicates that the IL-18-607A/C polymorphism is a risk factor for RA, while there is no clear evidence to support the association between MCP-1-2518A/G polymorphism and risk of RA.

Key words: Rheumatoid arthritis, Interleukin-18, Meta-analysis, Monocyte chemoattractant protein-1