Relationship between sonographic parameters and YKL-40 levels in rheumatoid arthritis
Kazakova M et al. – The findings suggest that YKL–40 might be implicated in the pathogenesis of the disease and could indicate the level of joint inflammation. Methods In this study, the authors evaluated YKL–40 levels in serum and synovial fluid of patients with rheumatoid arthritis in comparison with the ultrasonographic findings. YKL–40 levels were measured by enzyme–linked immunosorbent assay in 25 patients with active rheumatoid arthritis and in 40 healthy subjects. B mode and power Doppler were performed to determine synovial thickening and vascularization. Results
Serum YKL–40 level in patients was significantly higher than the concentration in healthy controls (P < 0.01). In patients with rheumatoid arthritis, the level of the glycoprotein in synovial fluid was remarkably elevated compared to the serum level (P = 0.003). The B mode and power Doppler scores correlated to YKL–40 in serum and synovial fluid (P = 0.07). Serum YKL–40 levels were related positively to serum markers of inflammation such as C–reactive protein (P = 0.004) and erythrocyte sedimentation rate (P = 0.003). This study is the first to demonstrate a relationship between YKL–40 levels and ultrasonographic examinations in Bulgarian patients with rheumatoid arthritis.