Collagen degradation by inflammatory phagocytes.

Inflammatory phagocytes are frequently found in the osteoarthritic joint. Current models of the pathogenesis of osteoarthritis (OA) would indicate that proteolytic modification of the cartilage extracellular matrix is important in the development of irreversible joint destruction. Neutrophils and macrophages contain collagenolytic proteinases with different substrate specificity and which are capable of degrading native collagens which are present in articular cartilage. The biochemical nature of these proteinases is discussed. Inflammatory phagocytes may contribute to the process of joint destruction in OA.