Rheumatoid arthritis (RA) is a chronic inflammatory disease that is characterized by severe tissue damage and chronic synovial inflammation. Several promising biomarkers need further development and refinement to attain sufficient sensitivity and specificity. In this study, we used a miRNAarray approach to identify new miRNA in exosome that are related to disease activity in patients with RA who showed inadequate response to treatment.
42 RA patients were included in the study. Disease activity was measured using the 28-joint disease activity score with ESR (DAS28-ESR). Patients with RA were stratified according to the following criteria: the clinical remission (CR) group (n = 22), DAS28-ESR < 2.6; and the non-CR group (n = 20), DAS28-ESR > 2.6. By exosome preparation, miRNA array, and Reverse Transcription-qPCR reactions, several miRNAs were as potent markers for disease activity.
After data processing for relative quantification of miRNA in exosome between the CR and non-CR groups, we identified 47 miRNAs with a relative fold change (non-CR/CR) > 2. To validate these results, five miRNAs were selected showing at least 2-fold change between the CR and non-CR groups. Both levels of hsa-miR-1915-3p and hsa-miR-6511b-5p were significantly increased in CR group; hsa-miR-1915-3p was 43.75 in the CR group and 24.68 in the non-CR group (ρ = 0.004), and hsa-miR-6511b-5p was 3.02 in the CR group and 2.45 in the non-CR group (ρ = 0.03).
hsa-miR-1915-3p showed promise as additional markers for evaluating disease activity in patients with RA.