Clinical significance of soluble-triggering receptor expressed on myeloid cells-1 (sTREM-1) in patients with rheumatoid arthritis

Abstract Aim of the work To assess serum concentrations of triggering receptor expressed on myeloid cells-1 (sTREM-1) in rheumatoid arthritis (RA) patients, and correlate them with the main clinical, serological, radiological features and functional capacity of RA patients. Patients and methods Sera from 61 RA patients, and 30 healthy controls were assayed for sTREM-1 by Enzyme Linked Immunosorbant Assay. RA disease activity was assessed using 28-joint disease activity score (DAS-28). Assessment of patient’s functional capacity was done using modified health assessment questionnaire (mHAQ). Standardized X-rays were done to all RA participants and evaluated according to Larsen score Results Serum levels of sTREM-1 were significantly higher in RA patients vs healthy controls (57.61 ± 28.87 and 43.72 ± 10.64 ng/ml; p  = 0.027). These levels were higher in patients with severe disease activity (68.27 ± 36.14 ng/ml) than those with mild and moderate disease activity (43.50 ± 6.49 ng/ml and 47.52 ± 12.26 ng/ml, respectively; p  = 0.008). On the contrary, no significant difference was found in levels of sTREM-1 in patients with extra-articular involvement or positive RF than those without. Levels of sTREM-1 showed a highly significant positive correlation with DAS-28 ( P  = 0.001), ESR ( P  = 0.02) and mHAQ ( p  = 0.003).There were no significant correlations between sTREM-1 level with age, disease duration, morning stiffness, nor radiological narrowing and erosion scores. Conclusion Levels of sTREM-1 were elevated in RA patients and correlated significantly with clinical and laboratory markers of disease activity as well as functional disability (as determined by mHAQ). To confirm our results we propose that larger scale, multicenter studies with longer evaluation periods are needed.