ASSOCIATION BETWEEN DEGREE OF BONE-EROSION AND SYNOVIAL FLUID-LEVELS OF TUMOR-NECROSIS-FACTOR-ALPHA IN THE KNEE-JOINTS OF PATIENTS WITH RHEUMATOID-ARTHRITIS

Objective: To determine whether concentrations of cytokines and matrix -degrading enzymes in synovial fluid of patients with rheumatoid arthr itis or osteoarthritis are associated with the degree of bone-destruct ion in the same joint. Methods: Determination of Interleukin-1 alpha, IL-1 beta, IL-1-receptor-antagonist, IL-6, IL-8, tumor necrosis factor alpha (by ELISA), collagenase-activity and caseinase-activity (by sub strate-assays) in the SF (knee) of patients with RA (n42) or OA (n35). The degree of bone-destruction was assessed radiographically. Results : SF cytokine- and enzyme-levels were higher in patients with RA than in those with OA. In the RA group, SF-levels of TNF alpha were positiv ely correlated with the degree of bone destruction of the respective j oint. No correlation was found between radiographically assessed joint changes and SF-concentrations of other cytokines, enzyme activities, serum CRP, or duration of disease. In the OA-group, none of the examin ed parameters was associated with the degree of joint destruction. Con clusions: Our data may support the assumption of TNF alpha playing an important role in joint destruction in RA. Possible alternative conclu sions are discussed.