Characterisation of peripheral blood mononuclear cell microRNA in early onset psoriatic arthritis

OBJECTIVES: To evaluate the micro-RNA (miRNA) expression profile in patients with early psoriatic arthritis (PsA) in order to assess the role of miRNAs as potential PsA biomarkers. METHODS: The expression of 723 mature miRNAs in peripheral blood mononuclear cells of early PsA patients in comparison with early-rheumatoid arthritis (ERA) patients and healthy controls (HC) was evaluated using a miRNA microarray. All patients had active disease and were naïve from treatment. The results were validated for a specific miRNA (miR-21-5p) in the entire series of patients plus an additional group of early PsA, ERA and HC using droplet digital PCR. RESULTS: In PsA, microarray analysis revealed a distinct pattern of 19 (vs. HC) and 48 (vs. ERA) deregulated miRNAs (p