Collagenase and its natural inhibitors in relation to the rheumatoid joint.

This report attempts to summarize our present knowledge of rheumatoid synovial collagenase and its natural serum inhibitors, beta1-anticollagenase and alpha2-macroglobulin, in relation to cartilage collagen resorption in the rheumatoid joint. Immunolocalization of collagenase across the cartilage/pannus junction is described, and in the light of the finding of the specific, small molecular weight beta1-anticollagenase we propose a model of cartilage erosion based on the interaction between collagenase and its natural inhibitors.