Osteoarthritis of the knee – clinical assessments and inflammatory markers11Supported by a grant from the Robert Bosch Stiftung, Stuttgart, Germany.

Abstract

Objective: The present cross sectional study was performed to test the hypothesis that in osteoarthritis (OA) of the knee severity of this disease is related to local levels of inflammatory metabolites and their corresponding enzymes.Methods: From 41 patients with OA of the knee (age range 45-79 years) undergoing arthroscopy blood, synovial fluid (SF) and synovial membrane (SM) were collected. Clinical conditions were primarily assessed by the WOMAC-index and radiographic grading (K&L-grade). Concentrations of PGE 2 , TxB 2 and NO 2/3 and that of IL-6, IL-1 , IL-1 , TNF , COX-2 and iNOS were determined in SF and SM, respectively.Results: With advancing age K&L-grade and COX-2 in SM increased significantly (P=0.005 and P=0.01, respectively). TNF and IL-1 were not detectable in SM samples. Apart from a correlation between PGE 2 and WOMAC-index (r=0.36, P=0.035) no significant relationships could be found between the various inflammatory parameters and any of the assessed clinical signs.Conclusions: Apparently no direct relationships exist between the measured markers of inflammation (e.g. PGE 2 , NO 2/3 ) or the involved enzymes (e.g. COX-2, iNOS) and the severity of OA of the knee. The degenerative condition of this disease might be due to the more local, mainly mechanical injury with little systemic upset. However, further longitudinal studies are needed to clarify whether the assessed biochemical markers could serve as predictors for the progression of OA.

The effect of intra-articular botulinum toxin A on substance P, prostaglandin E2, and tumor necrosis factor alpha in the canine osteoarthritic joint

“…This is in accordance with the study by Trumble et al [14], in which the SF PGE 2 concentration correlated with various pain measures in dogs with experimental OA, and with the study by van Loon et al [15], in which it correlated with pain and lameness in horses with experimentally induced synovitis. Positive correlation between PGE 2 and an index of pain, stiffness, and physical disability has also been reported in osteoarthritic human patients [16]. To the authors’ knowledge, this correlation has not been previously studied in dogs with chronic, naturally occurring OA.…”

“…It is produced by the action of the cyclooxygenase (COX) enzymes in various cells [3]. The SF concentration of PGE 2 correlates positively with osteoarthritic pain in dogs [14], horses [15], and humans [16, 17]. Substance P enhances the release of PGE 2 from chondrocytes [18], and the concentrations of SP and PGE 2 correlate with each other in the SF of osteoarthritic horses [6].…”

Tiludronate treatment improves structural changes and symptoms of osteoarthritis in the canine anterior cruciate ligament model

“…The analyses of synovial fluid confirmed the anti-inflammatory effects reflected by a decrease in the levels of PGE 2 and NOx, two well-known inflammatory mediators [39]. Inflammatory markers such as PGE 2 are known to be correlated with pain and functional disability in human OA [40] as well as in the canine ACL model of OA [41]. The high level of synovial fluid NOx found in this study is in line with our previous findings in this OA model, in which the inducible NOS was found to be increased [16,34].…”

Associations between proinflammatory cytokines in the synovial fluid and radiographic grading and pain-related scores in 47 consecutive patients with osteoarthritis of the knee

“…These studies add importance to the present findings that TNFα inhibition may improve the WOMAC score and that increased IL-6 activity in earlier phases of OA prevents cartilage destruction. Brenner et al performed a similar experiment using the synovial membranes and fluid from OA patients, and reported that TNFα was undetectable in their synovial fluid and that there were no correlations between IL-6 levels and WOMAC pain subscores [19]. Regarding TNFα, some controversy exists among studies.…”