PBMC miRNA in diagnosis of rheumatoid arthritis

Abstract

Background and objective: RA is an autoimmune disorder mediated by autoantibodies. miRNAs have been shown to negatively regulate protein translation via an antisense RNA-RNA interaction. Altered miRNA expression has been well established in autoimmune diseases. In this study, the expression of four microRNA was analysed. Also, correlation between microRNA and immunological markers was examined. Method: RNA was isolated from PBMC obtained from 100 RA patients and age-gender matched healthy controls. Levels of mature miRNA of miR146a, miR155a, miR499 and miR124a were detected using real time PCR. Downstream cytokine was analysed using ELISA from R&D systems. Result: Real time PCR reveals that the expression of miR-146a, miR-155a, miR-499 in PBMC was found to be down regulated in RA patients when compared to the controls by fold change of 0.15, 0.69 and 0.04 respectively whereas, expression of miR124a was found to be low to detect. Expression of TNF- alpha upregulated (p-value=0.09) and IL6 was found to be insignificantly down regulated in patient. miRNA 155a was found to be in significant negative correlation with rheumatoid factor (r= -0.210; p=0.038).