title: Relationship between sonographic parameters and YKL-40 levels in rheumatoid arthritis.
abstract: YKL-40, also known as human cartilage glycoprotein 39, is a member of the "mammalian chitinase-like proteins" family without chitinase activity. Increased serum concentrations are associated with inflammatory processes and several types of cancer. In this study, we 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. 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. The findings suggest that YKL-40 might be implicated in the pathogenesis of the disease and could indicate the level of joint inflammation.
authors.affiliation: Department of Medical Biology, Medical University-Plovdiv, 15A V. Aprilov Blvd, 4002 Plovdiv, Bulgaria.
authors.forename: Maria
authors.initials: M
authors.lastname: Kazakova
authors.forename: Anastas
authors.initials: A
authors.lastname: Batalov
authors.forename: Tanya
authors.initials: T
authors.lastname: Deneva
authors.forename: Nonka
authors.initials: N
authors.lastname: Mateva
authors.forename: Zlatimir
authors.initials: Z
authors.lastname: Kolarov
authors.forename: Victoria
authors.initials: V
authors.lastname: Sarafian
mesh_terms: D054392:Adipokines / Q000032:analysis* / Q000097:blood; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000378:metabolism; D015415:Biomarkers; D002097:C-Reactive Protein / Q000032:analysis; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D006801:Humans; D037102:Lectins / Q000032:analysis* / Q000097:blood; D008297:Male; D008875:Middle Aged; D013582:Synovial Fluid / Q000737:chemistry*; D013583:Synovial Membrane / Q000473:pathology; D014463:Ultrasonography
chemical_list: D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D037102:Lectins; D002097:C-Reactive Protein