Plasma Levels of MicroRNA-146a-5p, MicroRNA-24-3p, and MicroRNA-125a-5p as Potential Diagnostic Biomarkers for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that is characterized by inflammation of the articular tissue. This study aims to evaluate the expression of microRNA (miR)-146a-5p, miR-24-3p, and miR-125a-5p in the plasma of RA patients and compare them with those of healthy controls to obtain a specific expression profile for earlier diagnosis and assistance in treating patients. This study was performed on 50 RA patients and 50 healthy controls. Five microliters of blood were taken from each patient/control. Plasma RNA was extracted using the Trisol solution. cDNAs were synthesized; using moloney murine leukemia virus (MMLV) and deoxynucleoside triphosphate (dNTP). Real-time PCR was performed using SYBR green kit. The mean expression of miR-146a-5p, miR-24-3p, and miR-125a-5p in the RA group were 8.1 +/- 1.9, 6.5 +/- 1.2, and 6.8 +/- 2.2 and in the healthy group were 4.8 +/- 1.6, 3.6 +/- 2.2, and 3.4 +/- 1.7, respectively. Significant differences were also observed in the mean expression of these three miRNAs in four subgroups of RA patients with different disease activity based on disease activity score 28 (DAS28) (p<0.05). ROC curve analysis showed that miR-146a-5p (AUC=0.8, sensitivity=96%, specificity=86%), miR-24-3p (AUC=0.7, Sensitivity=95%, Specificity=75%) and miR-125a-5p (AUC=0.71, sensitivity= 93%, specificity=84%) could be used as suitable biomarkers for RA diagnosis. Increased expressions of miR-146a-5p, miR-24-3p, and miR-125a-5p in RA patients indicate that the miRNAs are involved in disease incidence and progression, and the measurement of their expression can play an essential role in the diagnosis and treatment of the disease.