RESUMO
Rheumatoid arthritis (RA) is characterized by ongoing joint destruction. MicroRNAs (miRs) are blood-based biomarkers linked to RA pathogenesis. The musculoskeletal ultrasonography seven-joint score (US7) is an objective tool to assess RA activity. We aimed to evaluate miR-223 and miR-16 roles in monitoring RA activity and to investigate if there is a link between their plasma levels and US7 score. This study enrolled 76 RA patients classified according to Disease Activity Score 28-joint count with erythrocyte sediment rate (DAS28-ESR) to inactive cases (n = 38) and active cases (n = 38). Each patient's joint was scored for synovial proliferation (gray-scale ultrasound 'GSUS7') and vascularization (power Doppler ultrasound 'PDUS7'). Real-time quantitative PCR was used to measure the expression levels of miR-16 and miR-223 in plasma. When compared to inactive group, the active group revealed significant upregulation of miR-16 and miR-223, (P = 0.001 and P = 0.02, respectively). miR-16 and miR-223 levels were correlated with synovitis PDUS7 (r = 0.34, p < 0.01 and r= 0.25, P = 0.03, respectively). miR-16 was also positively correlated with synovitis GSUS7 (r= 0.42, p < 0.001). miR-223 upregulation discriminated active from inactive RA patients at AUC = 0.64, with 76% sensitivity and 50% specificity at cutoff > 2.8-fold change), whereas miR-16 distinguished the two groups at AUC = 0.78 with 87% sensitivity and 53% specificity at cutoff >38.27-fold change. In conclusion, upregulated miR-16 may have more potential to serve as activity biomarkers than miR-223 in RA. The miR-16 level was linked to synovitis GSUS7 and synovitis PDUS7 changes but miR-223 only linked to synovitis PDUS.
