FRI0007 IDENTIFICATION AND VALIDATION OF PLASMA MICRO-RNA 425–5P AND -451A AS MICRO-RNAS ASSOCIATED WITH CARDIOVASCULAR DISEASE RISK OBSERVED IN RHEUMATOID ARTHRITISPATIENTS

Abstract

Background: Cardiovascular disease (CVD) risk is increased in Rheumatoid arthritis (RA) patients, and therefore, improved approaches for its early detection are needed. An accelerated atherosclerosis is considered the cause of the increase CVD risk. As microRNAs (miRNAs) are increasingly recognized as critical regulators in atherosclerosis and possess excellent stability in plasma, this study focused on using miRNAs as noninvasive CVD risk biomarkers in RA patients. Objectives: To identify plasmatic miRNAs in RA patients that can facilitate earlier diagnosis of CVD and provide insight regarding the increase risk for CVD observed in these patients. Methods: A discovery and validation studies were performed. To discover miRNAs candidates, we first compared plasmatic profiles of 754 miRNAs in 7 RA patients without CVD, in 7 patients with acute myocardial infarction (AMI) but without RA, and in 7 healthy controls matched for age and for classical CV risk factors. miRNAs commonly expressed in the two group of patients but differentially expressed from the controls were selected as miRNA candidates for validation. Selected miRNAs were validated in independent serum samples from 214 RA patients (validation cohort) by studying its association with subclinical atherosclerosis measured by carotid intima-media thickness (cIMT). Plasma profile of miRNAs in the discovery study was analyzed using validated TaqMan Open Array miRNA panels which enables the quantification of 754 human miRNAs. Differential expression analysis was performed with Expression Suite software and selected miRNAs candidates were validated in the validation study by real-time PCR with LNA™ microRNA qPCR assays and analyzed with 2–DCt method. KrusKal-Wallis test, Dunns post-test and linear regression were used for statistical analyses. Results: In the discovery study we were able to measure 379 (50%) of the miRNAs represented in the array. We observed than 10 miRNAs (miRNA-Let-7a, miRNA-96, miRNA-381, miRNA-451a, miRNA-518d, miRNA-425-5p, miRNA-572, miRNA-190b, miRNA-708, and miRNA-1180) were expressed at the same level in RA and AMI patients but were significantly downregulated compared with controls. These 10 miRNAs were selected as potentially miRNAs associated with the increase risk of CVD in RA patients. Four of those miRNAs were expressed at very low level and were discarded for the validation study. In the validation study with 214 plasma samples from RA patients, we observed that two of the six candidate miRNAs (miRNA-425-5p and miRNA-451a) were significantly associated with cIMT. Thus, adjusted multivariable linear regression analysis showed that miRNA-425-5p and miRNA-451a independently explained 1.4% of the cIMT variability. Furthermore, adjusted regression estimates of the effect of miRNA-425-5p and miRNA-451a on cIMT were β = 0.029mm; p = 0.037 and β = -0.035 mm; p = 0.039, respectively. No other miRNA candidate exhibited association with cIMT values. Furthermore we observed that miRNA-425-5p was significantly correlated with ESR (r=-0.136; p=0.024) and miRNA-451a with DAS28 (r=0.19; p=0.003), ESR (r=0.23; p=0.0001), CRP (r=0.15; p=0.016) and fibrinogen (r=0.28; p=0.0001). miRNAs concentrations were not affected by any of the AR treatments. No association was observed between the presence of carotid plaque and the expression level of the microRNAs tested. Conclusion: In the present study, we have identified miRNA-425-5p and miRNA-451 as potentially miRNAs involved in the CVD risk observed in RA patients. Acknowledgement: The authors thank the patients and healthy controls for their participation in the study Disclosure of Interests: SILVIA PAREDES Speakers bureau: Bristol, Roche, Amgen, Pfiser, Abbvie, lilly, UCB, Delia Taverner Speakers bureau: amgen, pfiser, Bristol, Lilly, Roche, Raimon Ferre: None declared, Josep Maria Alegret Speakers bureau: Daichii, Lluis Masana Consultant for: amgen, daichii, sanofi, Speakers bureau: AMGEN, SANOFI, MYLAN, Joan Carles Vallve: None declared