Résumé
Objective To investigate the expression of miRNA-31 in peripheral blood mononuclear cells (PBMCs) of rheumatoid arthritis (RA) patients,and the relationship between miRNA-31 and disease activity of RA.Methods After obtaining the informed consent,peripheral blood samples of 56 RA patients,12 systemic lupus erythematosus (SLE) patients,6 Sj(o)gren's syndrome (SS) patients and 30 healthy controls were collected from the Department of Rheumatology,Peking University Third Hospital.RNA was extracted from the PBMCs which were separated by Ficoll-Paque PLUS.The expression of miRNA-31 in the PBMCs of RA patients,SLE patients,SS patients and healthy controls was detected by real-time Polymerase Chain Reaction (PCR).Furthermore,according to the RA disease activity score (DAS28),RA patients were divided into high,moderate and low disease activity groups and remission group,and miRNA-31 expression was compared between different groups.Data were analyzed using t test or Mann-Whitney U test.Results The expression of miRNA-31 in PBMCs of RA patients was 7.25 times (P=0.003 8) higher when compared with that of the control group.To be specific,the expression of miRNA-31 was 10.63 times in PBMCs of high activity RA group (P=0.01) and 8.95 times in moderate activity RA group (P=0.000 3) when compared with that of the control group,and there was no significant difference between low activity,remission groups and control groups in terms of miRNA-31 expression.Furthermore,the expression of miRNA-31 in PBMCs of SLE patients was not significantly different from the control and miRNA-31 expression in PBMCs of SS patients was 1.64 times (P=0.02) higher than that of the RA patients,but the average level of miRNA-31 was much less than that of RA patients.The increased miRNA-31 may serve as a diagnostic marker for disease activity of RA.