Helsinki Declaration). The isolated fluid/cells were cultured in vitro, and the expression of well-known MSC, hematopoietic, endothelial markers as well as high-end glycosylation products were measured by flow cytometry. In vitro differentiation assays were used to determine the stemness of SYF-MSCs. The immu- nosuppressive function of these cells was studied by mitogen- activated lymphocyte reaction, and their immunophenotype was investigated by cell activation with TLR ligands and pro-inflam- matory cytokines; the secreted cytokines were measured by ELISA. Results The cells isolated from synovial fluid of patients with RA grew as monolayers in vitro and could be maintained in cul- ture for more than 10 passages. The cells expressed the most important MSC markers (CD44, CD73, CD90 and CD105) with absence of endothelial (CD31, VEGFR2) or hematopoietic cell markers (CD34, CD45, CD69, CD133), respectively. SYF- MSCs were able to differentiate into bone, fat and cartilage tis- sue in vitro fulfilling the ISCT criteria, and could suppress the proliferation of mitogen activated peripheral blood lymphocytes. Furthermore, SYF-MSCs secreted increased amount of IL-6 after 12 and 24 h treatment by LPS (15423.61 + 9348.61 pg/ml at 12 h; 17479.17 + 3848.63 pg/ml at 24 h time points), Poly:IC (15215.28 + 10834.72 and 24090.28 + 3626.40 pg/ml), TNFa (7437.5 + 1168.06 and 11562.5 + 845.83 pg/ml) and IL-1b (19465.28 + 2306.94 and 21229.17 + 12.5 pg/ml) compared to untreated controls (1590.28 + 1015.28 and 2187.50 + 640.28 pg/ml), respectively. IL-8 could be detected in the super- natants of SYF-MSC only upon LPS (10876.76 + 7553.24 and 12117.94 + 2912.06 pg/ml), Poly:IC (8972.35 + 8707.65 and 30567.94 + 3637.94 pg/ml) TNFa (5516.47 + 1336.47 and 110325.29 + 5645.29 pg/ml) and IL-1b (18063.53 + 3083.53 and 24970.88 + 9940.88 pg/ml) treatment, but not in the untreated controls. Conclusions The in vitro data suggest that SYF-MSC may play a role in the inflammatory processes of RA, and their activation could lead to the release of pro-angiogenic cytokines as well. A6.24 DOES THE ALTERED EXPRESSION OF MICRO-RNA-155 AND MICRO-146A IN SYNOVIAL FLUID OF RHEUMATOID ARTHRITIS PATIENTS CORRELATE WITH THE ULTRASOUND SCORES FOR ACTIVE SYNOVITIS? 1 R Shumnalieva, 2 D Kachakova, 1 S Monov, 2 R Kaneva, 1 Kolarov Zl, 1 R Rashkov. 1 Clinic of Rheumatology, Department of Internal Medicine, Medical University, Sofia, Bulgaria; 2 Molecular Medicine Center, Department of Chemistry and Biochemistry, Medical University, Sofia, Bulgaria 10.1136/annrheumdis-2015-207259.150 Background Micro-ribonucleic acids (microRNAs) comprise a class of non-coding small microRNA that regulates gene expres- sion on posttranscriptional level. Altered expression profile of certain microRNAs has been found in the peripheral blood (PB), synovial fluid (SF) and synovial fibroblasts of rheumatoid arthri- tis (RA) patients. The use of microRNAs as biomarkers for RA in the clinical practice is based on correlation between their expres- sion levels and scores for disease activity and progression. We found that altered expression of certain microRNAs in SF of RA patients correlate with the ultrasound scores for active synovitis. Materials and methods 46 RA patients according to the 1987 ACR criteria were included in the study. Before an arthrocentesis we performed ultrasound assessment and scoring of the joint inflammation by using both grey scale and power Doppler tech- nic for defining the synovial thickening and degree of vascularisation. MicroRNA-155 and -146a expression levels in paired PB and SF samples were investigated through PCR (SYBR Green technology) and compared to healthy controls (HCs). Results SF in 80,43% and in 69,55% (p < 0.05, T-test) of RA patients showed overexpression of microRNA-155 and micro- RNA-146a, respectively, when compared to the HCs. There was a good correlation of microRNA-155 expression level and the ultrasound score for active synovitis grade ‡ 2 (Spearman’s cor- relation coefficient 0.313, p < 0.016) and for microRNA-146a (Spearman’s correlation coefficient 0.241, p < 0.066). The levels of microRNA-155 and -146a correlated with the presence of erosions (Spearman’s correlation coefficient 0.373, p < 0.004 and 0.318, p < 0.014, respectively) and the imaging score (Spearman’s correlation coefficient 0.412, p < 0.001 and 0.341, p < 0.008, respectively). Conclusion The laboratory and imaging data showed correla- tion between the expression levels of the chosen microRNAs with the active joint inflammation and destruction. Differences could be explained by the different disease stage and progres- sion characterised by higher erosion score and tendency to lesser synovial thickened and vascularisation as well as by the possibility of different expression levels of microRNA though the disease course. Further analysis with higher number of patients is needed to confirm if these microRNAs could be used in the clinical practice as local biomarkers for both disease activity and progression. Acknowledgement The study was supported by Grant 55/2013 funded by Medical University – Sofia, Bulgaria A6.25 SERUM CONCENTRATIONS OF VASCULAR ENDOTHELIAL GROWTH FACTOR IN SYSTEMIC LUPUS ERYTHEMATOSUS – ASSOCIATION WITH AUTOANTIBODY PROFILE AND CARDIOVASCULAR INVOLVEMENT 1 K Fischer, 2 H Przepiera-Będzak, 2 L Ostanek, 3 A Walecka, 3 M Sawicki, 1 I Brzosko, 2 M Brzosko. 1 Independent Laboratory of Rheumatologic Diagnostics, Pomeranian Medical University in Szczecin, Poland; 2 Departament of Rheumatology and Internal Medicine, Pomeranian Medical University in Szczecin, Poland; 3 Department of Diagnostic Imaging and Interventional Radiology, Pomeranian Medical University in Szczecin, Poland 10.1136/annrheumdis-2015-207259.151 Background and objectives Angiogenesis plays a significant role in the pathogenesis of systemic lupus erythematosus (SLE). Vas- cular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis as well as vasculogenesis. The study was designed to evaluate the association between VEGF concentrations and immunological parameters, inflammatory markers, classical athe- rosclerosis risk factors and vascular disorders in SLE patients. Materials and methods The study was performed in 83 patients with SLE and 20 age and gender matched controls. The concentrations of VEGF was determined with ELISA method using R&D Systems tests. The presence of inflammatory markers (ESR, CRP and fibrinogen) and selected autoantibodies - anti-endothelial (AECA), anti-nuclear, anti-phospholipid (aPL) and anti-neutrophil cytoplasmic was evaluated. Classical risk fac- tors for atherosclerosis as well as selected organ manifestations (cardiovascular and central nervous system, lupus nephritis, thromboembolic disorders and vasculitis) were taken into account. Carotid intima-media thickness and atherosclerotic pla- ques were measured with B-mode ultrasound method. Statistical analysis was performed with chi 2 Yates, chi 2 Pearson, rank EWRR Abstracts Ann Rheum Dis 2015;74(Suppl 1):A1–A102 A65