IntroductionThe advent of anti-tumor necrosis factor alpha (anti-TNFα) drugs has considerably improved medical management in rheumatoid arthritis (RA) patients, although it has been reported to be ineffective in a fraction of them. MicroRNAs (miRNAs) are small, non-coding RNAs that act as fine-tuning regulators of gene expression. Targeting miRNAs by gain or loss of function approaches have brought therapeutic effects in various disease models. The aim of this study was to investigate serum miRNA levels as predictive biomarkers of response to anti-TNFα therapy in RA patients.MethodsIn total, 95 RA patients undergoing anti-TNFα/disease-modifying antirheumatic drugs (anti-TNFα/DMARDs) combined treatments were enrolled. Serum samples were obtained at 0 and 6 months and therapeutic efficacy was assessed. miRNAs were isolated from the serum of 10 patients before and after anti-TNFα/DMARDs combination therapy, cDNA transcribed and pooled, and human serum miRNA polymerase chain reaction (PCR) arrays were performed. Subsequently, selected miRNAs were analyzed in a validation cohort consisting of 85 RA patients. Correlation studies with clinical and serological variables were also performed.ResultsNinety percent of RA patients responded to anti-TNFα/DMARDs combination therapy according to European League Against Rheumatism (EULAR) criteria. Array analysis showed that 91% of miRNAS were overexpressed and 9% downregulated after therapy. Functional classification revealed a preponderance of target mRNAs involved in reduction of cells maturation - especially on chondrocytes - as well as in immune and inflammatory response, cardiovascular disease, connective tissue and musculoskeletal system. Six out of ten miRNAs selected for validation were found significantly upregulated by anti-TNFα/DMARDs combination therapy (miR-16-5p, miR-23-3p, miR125b-5p, miR-126-3p, miRN-146a-5p, miR-223-3p). Only responder patients showed an increase in those miRNAs after therapy, and paralleled the reduction of TNFα, interleukin (IL)-6, IL-17, rheumatoid factor (RF), and C-reactive protein (CRP). Correlation studies demonstrated associations between validated miRNAs and clinical and inflammatory parameters. Further, we identified a specific plasma miRNA signature (miR-23 and miR-223) that may serve both as predictor and biomarker of response to anti-TNFα/DMARDs combination therapy.ConclusionsmiRNA levels in the serum of RA patients before and after anti-TNFα/DMARDs combination therapy are potential novel biomarkers for predicting and monitoring therapy outcome.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-015-0555-z) contains supplementary material, which is available to authorized users.

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Objective— Previous studies have suggested a relationship between anticyclic citrullinated protein (CCP) levels and development of cardiovascular disease in rheumatoid arthritis (RA). However, a limited number of studies have demonstrated an involvement of anti-CCPs in those processes. This study was aimed to define the specific role of these auto-antibodies in the pro-oxidative, inflammatory, and proatherogenic profile observed in leukocytes from RA patients. Approach and Results— Seventy-five RA patients and 31 healthy donors were enrolled. Carotid intima media thickness was evaluated as atherosclerosis marker. Several procoagulant and inflammatory factors, leukocyte activation, and oxidative stress markers were analyzed in plasma and leukocyte subsets. Anti-CCPs were purified from plasma of RA patients, and in vitro treatment of healthy leukocytes was conducted. High titers of anti-CCPs were associated to altered expression of prothrombotic and inflammatory markers, high oxidative stress, and pathological carotid intima media thickness in RA patients. Notably, gene expression analysis showed that lymphocytes were major players in altered inflammatory profile, monocytes were responsible for the protrombotic and atherogenic status, and neutrophils mainly displayed a pro-oxidative feature. In vitro treatment with purified anti-CCPs fully recapitulated that pathogenic profile, promoting the activation of leukocytes. Conclusions— Anti-CCPs are key players in the inflammatory and proatherogenic status of RA patients. The effects are specific of the immune cell targeted, promoting overexpression of thrombotic, inflammatory, and pro-oxidative markers in monocytes; pro-oxidative status in neutrophils; and proinflammatory profile in lymphocytes. Targeting these autoantibodies would be an excellent strategy to prevent the development of cardiovascular disease in RA.