Circulating lnc-ITSN1-2 expression presents a high value in diagnosis of rheumatoid arthritis and correlates with disease activity.

This study was aimed to investigate the correlation of lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1 expressions in plasma by qPCR with rheumatoid arthritis (RA) risk and disease activity. 30 RA patients and 30 health controls (HC) were enrolled in this study. Plasma sample were collected from RA patients before any treatment carried out and HCs. Top 3 RA related long non-coding RNAs (lncRNAs) (lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1) were selected by a computational framework prediction. The expression of lnc-ITSN1-2, lnc-APOC3-2 and lnc-AL355149.1 were determined by qPCR method. Age (P=0.350) and gender (P=0.542) were similar between RA patients and HCs. lnc-ITSN1-2 level was extremely increased in RA patients compared with HCs (P<0.001), while both lnc-APOC3-2 and lnc-AL355149.1 expressions were numerically higher in RA patients but with no statistical significance (P=0.152 and P=0.139 respectively). Receiver Operating Characteristic (ROC) curves were performed and we found lnc-ITSN1-2 disclosed a great diagnostic value for RA with area under curve (AUC) 0.898, 95% CI 0.813-0.983, and sensitivity was 90.0% and specificity was 80.0% respectively at the best cut-off point. In addition, plasma lnc-ITSN1-2 level was illuminated to be positively associated with erythrocyte sedimentation rate (ESR) (P=0.049), C-reactive protein (CRP) (P<0.001) and disease activity score in 28 joints (DAS28) (P=0.007). Circulating lnc-ITSN1-2 expression was observed to be a novel and convincing biomarker for RA diagnosis as well as disease management. IJCEP