Monocyte chemoattractant protein-1 (MCP-1)-2518 A/G polymorphism and lupus nephritis risk

BACKGROUND Monocyte chemoattractant protein-1 (MCP-1) plays an important role in the development of allergic inflammatory reactions by recruiting various immune cells, which is associated with many autoimmune diseases, but the association with the MCP-1-2518A/G gene polymorphism and lupus nephritis (LN) was still controversial in previous studies. Thus, we performed a meta-analysis to derive a more precise evaluation of the association between MCP-1 -2518A/G polymorphism and LN risk and evaluated influence of ethnicity and source of controls. METHODS A systematic review and meta-analysis that will be performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Relevant literatures dated to September 2016 were acquired from the PubMed, EMBASE, Cochran Library databases. A total of 961 LN cases and 1867 controls were extracted from 10 published case-control studies. We used odds ratios (OR) with 95% confidence intervals (CI) to assess the risk of LN with MCP-1-2518A/G. RESULTS Our meta-analysis suggested that MCP-1-2518A/G polymorphism was associated with the risk of LN (GG vs AG+AA: P < .01, OR = 1.42, 95% CI: 1.13-1.79 and A vs G P = .02, OR = 0.74, 95% CI: 0.58-0.95). Then the subgroup analysis showed MCP-1 -2518 A/G gene has a certain correlation with LN susceptibility in the American population (GG vs AA: P < .01, OR = 5.70, 95% CI: 2.09-15.50, GG vs AG+AA: P < .01, OR = 3.31, 95% CI: 1.97-5.54, GG+AG vs AA: P < .01, OR = 2.86, 95% CI: 1.14-7.18, and A vs G: P < .01, OR = 0.43, 95% CI: 0.24-0.79), while no significant risk in Europeans and Asians. CONCLUSION The current meta-analysis suggests that the MCP-1-2518A/G polymorphism is associated with an increased risk of LN, especially in the American population. However, better-designed studies with larger sample sizes are needed to validate the results.