Genetic Analysis of Common Variants of MMPs and their Involvement in Rheumatoid Arthritis in the East Midlands, UK
Introduction: Rheumatoid arthritis (RA) affects around 1% of population and causes irreversible synovial joint damage and bone erosion. Matrix metalloproteinases (MMPs) play a role in pathologic processes; however their involvement in RA is not clear. This study investigated the association of MMP2, MMP7 and MMP9 with RA. Methods: DNA samples from European (103 controls, 125 patients) and South Asian (91 controls, 115 patients) populations were genotyped for MMP7 (rs11568818), MMP9 (rs17576) and MMP2 (rs2241145). Diplotype and triplotypes analyses were performed. Results: An individual is twice as likely to develop RA if they have an AG genotype at both the MMP9 and MMP7 loci in European (OR 2.2, CI 1.03-4.70) or South Asian population (OR 2.28, CI 1.00-5.20). A CG genotype at the MMP2 locus and AG at MMP9- 836 gives protection within a European population (OR 0.34, CI 0.17-0.70). Heterozygous genotype combination on all three loci in South Asians increases risk of RA by three times (OR 3.27, CI 1.04-10.20). South Asians showed a significant doubling of RA risk with a total genetic risk score of three or more. Conclusion: Our results show that polymorphisms at these three MMP loci impact RA susceptibility and have a synergetic effect.