Detection of stromelysin and collagenase in synovial fluid from patients with rheumatoid arthritis and posttraumatic knee injury.

OBJECTIVE. To quantify stromelysin and collagenase in synovial fluid (SF) from patients with rheumatoid arthritis (RA) or traumatic knee injury. METHODS. Stromelysin and collagenase were measured in the SF of 33 patients with RA or posttraumatic knee injury, using specific double-antibody sandwich enzyme-linked immunosorbent assays. Stromelysin was fractionated from representative SF, and the molecular form was identified by immunoblot analysis. RESULTS. The stromelysin concentration was approximately 20-fold higher than the collagenase concentration in the fluids from patients with RA and approximately 8-fold higher in the fluids from patients with traumatic injury. For both metalloproteinases, there was a higher enzyme concentration in RA SF than in the SF from patients with trauma (stromelysin 40.1 +/- 26 micrograms/ml [mean +/- SD] in RA SF, 8.5 +/- 15 micrograms/ml in trauma SF; collagenase 2.2 +/- 3.3 micrograms/ml in RA SF, 1.1 +/- 2.3 micrograms/ml in trauma SF). The majority of the stromelysin within the SF bound to reactive red-agarose and was identified as prostromelysin based on electrophoretic mobility and immunoblotting with monospecific antibodies. CONCLUSION. The finding of high levels of stromelysin in SF from patients with RA supports the proposal that this enzyme may play a role in the connective tissue degradation observed in this disease.