Collagenase in synovial fluid.

Free collagenase activity was demonstrated in all 13 normal, 5 osteoarthrotic and 54 rheumatoid synovial fluids studied. Osteoarthrotic, normal, and rheumatoid fluids showed a free collagenase content increasing in that order. However, the total activities after trypsin activation did not differ significantly. The concentrations of alpha1-at and alpha2-M in synovial fluids reflected those in sera. The complex interactions between serum inhibitors, and free or latent collagenase released from both synovial cells and leukocytes are discussed.