Vascular Endothelial Growth Factor and Endostatin in Synovial Fluid of Various Arthritic Conditions

Abstract

Introduction: Rheumatoid arthritis (RA), ankylosing spondylitis (AS), osteoarthritis (OA), and gout are common forms of arthritic conditions. Angiogenesis via involvement of many regulatory cytokines and angiogenesis inhibitors is important in the pathogenesis of arthritis. The goal of this study is to compare two major angiogenetic factors, vascular endothelial growth factor (VEGF) and endostatin, in synovial fluid (SF) among various arthritic conditions. Patients and Methods: We collected SF through arthrocentesis of knees in patients with RA, AS, OA and gout. The concentrations of VEGF and endostatin in synovial fluid were analyzed using enzyme-linked immunosorbent assay. The influence of disease activity at the time of arthrocentesis was assessed by comparing peripheral blood white blood cell count (WBC), synovial WBC (SWBC), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) with levels of VEGF and endostatin. Results: Synovial VEGF was the highest in RA, followed by gout, AS, and OA; however, endostatin was the highest in gout, then AS, RA, and OA. VEGF had positive correlation with SWBC and endostatin had negative correlation with SWBC. However, there was no correlation between either synovial VEGF or endostatin and ESR or CRP level. Conclusion: The concentrations of VEGF and endostatin in synovial fluid varied among different inflammatory forms of arthritis, and were related with inflammation status.