Circulating microRNA-23b as a new biomarker for rheumatoid arthritis

Abstract MicroRNA-23b (miR-23b) is associated with inflammation and autoimmune diseases. This study evaluated miR-23b expression and assessed its potential as a biomarker of disease activity for rheumatoid arthritis (RA). Differential expression of microRNAs was determined by miRNA microarray analysis in fibroblast-like synoviocytes (FLSs) from four trauma patients as healthy controls (HCs) and eight RA patients. The microarray results showed elevated expression of miR-23b in FLSs from RA patients and this finding was corroborated by real-time quantitative polymerase chain reaction (RT-qPCR) and in situ hybridization using synovial tissues (STs). Furthermore, we found miR-23b levels in plasma of RA patients were significantly higher than in HCs, and plasma miR-23b levels positively correlated with the erythrocyte sedimentation rate (ESR), hypersensitive C-reactive protein (hs-CRP), C-reactive protein (CRP), DAS28, and platelet (PLT) count (P   0.05). Moreover, patients with anorexia showed higher levels of miR-23b in plasma than those without anorexia. Similar results were observed with fatigue. Appropriate treatment for RA not only ameliorated the disease condition but also reversed the elevated plasma miR-23b level remarkably. These results suggest that circulating miR-23b may be a promising biomarker for RA disease activity.