Background Chemerin is an adipokine that is linked to adipogenesis and chemotaxis of the innate immune system. It is expressed on macrophage, dendritic cells, and synovial lining and sublining cells. It has been reported that chemerin has both pro-inflammatory and anti-inflammatory roles, and higher level of chemerin was detected in various chronic inflammatory diseases. Recent studies have showed that its expression is increased in the synovium of patients with rheumatoid arthritis (RA), and the chemerin may play an important role in the pathogenesis of RA. However, the association between plasma chemerin level and disease activity in RA patients remains unclear.
Objectives This study aims to determine whether plasma chemerin level is elevated in patient with RA and its correlation with disease activity and other parameters.
Methods This study includes 71 RA patients and 42 age- and sex- matched healthy controls. Plasma samples were obtained from healthy controls and patients with RA during active and inactive disease status. We assessed the clinical characteristics and laboratory parameters including body mass index (BMI), erythrocyte sedimentation rate, C-reactive protein, and disease activity score 28 (DAS28). The plasma level of chemerin and tumor necrosis factor (TNF)-α were determined using enzyme-linked immunosorbent assay (ELISA).
Results Plasma chemerin levels were significantly elevated in patients with RA compared with healthy controls (9.074 ± 13.513 ng/mL vs 0.370 ± 0.219 ng/mL, p < 0.001). In RA patients, plasma chemerin levels showed a negative correlation with BMI (γ= -0.264, p = 0.027). Adjusted plasma chemerin levels according to BMI were significantly higher in the active group (DAS28 ≥ 2.6) than in the inactive group (DAS28 < 2.6) (0.591 ± 0.879 ng/mL/Kg/m2 vs 0.220 ± 0.154 ng/mL/Kg/m2, p = 0.015). Plasma chemerin levels adjusted to BMI were correlated with DAS28 (γ = 0.340, p = 0.004), but not with plasma TNF-α levels.
Conclusions Patients with RA showed higher plasma chemerin levels than those of healthy controls. Adjusted plasma chemerin levels according to BMI were well correlated with RA disease activity. These findings suggest that plasma chemerin could play a role in the inflammatory process of RA rather than obesity, and that it may be a useful disease activity marker and a candidate target molecule for therapy in RA patients.
Disclosure of Interest None Declared