Lack of association of matrix metalloproteinase-3 gene polymorphism with susceptibility to rheumatoid arthritis: a meta-analysis.

Epidemiological studies have investigated the association between matrix metalloproteinase-3(MMP-3) gene-1171 5A/6A polymorphism and rheumatoid arthritis (RA), but the results were inconsistent. To evaluate the specific relationship, we performed a meta-analysis to clarify the controversies. The relevant literatures dated to December 07th 2013 were retrieved from PubMed, EMBASE and the China National knowledge Infrastructure (CNKI) databases. The number of the alleles and genotypes for MMP-3 were obtained. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the association between MMP-3 5A/6A promoter polymorphism and RA. All of the statistical analyses were conducted by STATA11.0 software. A total of 6 case-control studies covering 1451 cases and 1239 controls were included in the final meta-analysis. There was no significant association between MMP-3 5A/6A promoter polymorphism and RA in all genetic models (for 6A versus 5A: OR=1.19, 95% CI=0.91-1.56, P=0.203; 5A/6A versus 5A/5A: OR=1.31, 95% CI=0.89-1.92, P=0.174; 6A/6A versus 5A/5A: OR=1.78, 95% CI=0.68-4.61, P=0.238; the recessive model: OR=1.48, 95% CI=0.88-2.47, P=0.141; and the dominant model: OR=1.46, 95% CI=0.71-3.00, P=0.299). In the subgroup analysis by ethnicity, we obtained the similar results. We systematically investigate the association between MMP-3-1171 5A/6A polymorphism and RA susceptibility; however, the results show a lack of correlation. Considering the small sample size and the selection bias existed in some studies, further studies are needed to confirm the findings.