Search

Ultrasound can be used to objectively diagnose and evaluate disease activity in patients with rheumatoid arthritis (RA). We aimed to determine the value of a new automated hand ultrasound (AHUS) scanning device and a simplified 3-joint ultrasound scoring system (US3) in detecting synovitis in RA. We compared AHUS and traditional ultrasound (US) scanning in detecting synovial hyperplasia (SH), joint effusion, bone erosion and power Doppler (PD) synovitis in 49 patients. In addition, we compared the value of US3 (in which 3 proximal interphalangeal [PIP] and/or metacarpophalangeal [MCP] joints with the highest scores for swelling and tenderness were evaluated) with the 22-joint ultrasound scoring system (US22) in 26 patients. Almost perfect κ coefficients (0.86-0.937) were obtained between AHUS and traditional US in detecting SH, joint effusion, bone erosion and PD synovitis (p < 0.001). The intra-class correlation coefficient (ICC) between AHUS and traditional US was 0.955-0.995. Of the US3 findings in AHUS, SH synovitis and PD synovitis were positively correlated with DAS28-CRP (adjusted R2 = 0.421, p < 0.0001; adjusted R2 = 0.365, p < 0.0001). US3 was highly correlated with US22 in detecting SH and PD synovitis (R = 0.792, p < 0.01; R = 0.948, p < 0.01). Compared with US22, a more significant correlation was identified between US3 scores and most clinical and laboratory values. In conclusion, AHUS performed comparably to traditional US in detecting synovitis in RA, and US3 was highly consistent with US22 in assessing synovitis and was positively correlated with RA disease activity. [ABSTRACT FROM AUTHOR]

Irisin is a hormone-like factor secreted by muscle cells and produced by cleavage of the membrane protein fibronectin type III domain protein 5 (FNDC5), which exerts anti-inflammatory and anti-proliferative effects. However, the effects and the underlying mechanisms of irisin in rheumatoid arthritis (RA) are still unclear. Collagen-induced arthritis (CIA) model was induced in DBA/1 mice and then treated with irisin. Arthritis index, paw thickness, weight, number of affected paws, serum inflammatory factors and related pathological tests were measured. RA fibroblast-like synoviocytes (RA-FLSs) were pretreated with IL-1β and irisin, and the migration, proliferation, invasion, oxidative stress and mitochondrial related function of RA-FLSs were detected. Irisin significantly improved arthritis symptoms in CIA mice, as indicated by reduced arthritis index, alleviated paw thickness, decreased the number of affected paws and inhibited release of inflammatory factors. Irisin alleviated joint destruction, FLSs proliferation and the expression of YES-associated protein (YAP) and mitochondrial dynamic related protein 1 (Drp1) in the FLSs of CIA mice. In vitro experiment, irisin inhibited the proliferation, migration and invasion of RA-FLSs and improved oxidative stress induced by IL-1β, thereby restraining the pathogenic transformation of RA-FLSs. Mechanically, irisin suppressed the nuclear translocation of YAP, in turn, could reduce the synthesis of Drp1 protein and inhibit the mitochondrial fission of RA-FLSs, which was reversed by YAP agonists. Therefore, irisin has a protective effect on RA. Irisin inhibits the proliferation, migration, invasion and inflammatory response of RA-FLSs by inhibiting the YAP-Drp1 signaling pathway, which implies a potential therapeutic effect on RA. [ABSTRACT FROM AUTHOR]