CORRELATION OF ANTICYTOSKELETON ANTIBODY ACTIVITIES IN SYNOVIAL-FLUID WITH INTERLEUKIN-6 IN PATIENTS WITH OSTEOARTHRITIS AND INFLAMMATORY JOINT DISEASE

Synovial fluids and sera from patients with rheumatoid arthritis, psoriatic arthritis, yersinia arthritis, Behçet's syndrome, Crohn's disease, and osteoarthritis were tested for antinuclear antibodies and antibodies to five cytoskeletal components in sensitive enzyme-linked immunosorbent assay (ELISA) systems and for IL-6 concentrations in a proliferation assay (IL-6 dependent hybridoma cell line B13.29, subclone B9). Statistically significant correlations between antibody activities and IL-6 levels were found for vimentin antibodies (r= 0.56; p<0.05) and actin antibodies (r= 0.44;p<0.05). In patients with chronic and active disease like rheumatoid arthritis and psoriatic arthritis, optical densities measured by vimentin- and actin-ELISA were significantly different from those measured in patients with osteoarthritis. To date only a few reports exist concerning the incidence of antibodies in synovial fluids. We have shown to our knowledge for the first time that IL-6 seems to induce synovial fluid antibody activities restricted to cytoskeletal components of synoviocytes (i.e., vimentin and actin). Synovial fluid antibody activities against vimentin and actin appear to be markers of activity in patients with inflammatory joint disease. © 1990 Springer-Verlag.