Study of plasma levels of soluble triggering receptor expressed on myeloid cells-1 in rheumatoid arthritis and its correlation with disease activity and tumor necrosis factor-\u03b1

Abstract

Aim of the workThe triggering receptor expressed on myeloid cells-1 (TREM-1) is a cell surface receptor expressed mainly on monocytes and neutrophils. It acts as an amplifier of inflammatory response in acute and chronic inflammatory states. The aim of this work was to study the plasma-soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in rheumatoid arthritis (RA) patients and its correlation with disease activity and tumor necrosis factor-α (TNF-α).Patients and methodsThis study included 80 patients with RA and 20 age-matched and sex-matched controls. All were subjected to demographic, clinical, laboratory, and radiological studies using the 28-joint Disease Activity Score, erythrocyte sedimentation rate, complete blood count, and radiograph of both hands. Plasma levels of sTREM-1 and TNF-α were measured with enzyme-linked immunosorbent assay.ResultsRA patients had significantly higher sTREM-1 and TNF-a levels compared with controls (206.32±125.75 and 17.83±11.88; P<0.001) and (190.82±69.46 and 54.75±9.46; P<0.001). In RA patients, sTREM-1 levels were found to be positively correlated with 28-joint Disease Activity Score, erythrocyte sedimentation rate, and TNF-a level (r=0.408, P=0.001; r=0.287, P=0.010; r=0.749, P=0.001). sTREM-1 level was significantly increasing as patients had increasing disease activity (F-test=20.62; P=0.001).ConclusionRA patients had higher sTREM-1 and TNF-a level compared with controls, and sTREM-1 level was correlated with disease activity, suggesting that sTREM-1 plays a role in the inflammatory process associated with TNF-a, and it may be a useful disease activity marker in RA. TREM-1 may be a safe therapeutic strategy for RA, as blocking TREM-1 signaling was found to suppress inflammatory responses without affecting the immune system to fight bacterial infection.