Lysosomal Mechanisms of Tissue Injury in Arthritis

STUDIES during the past decade have indicated that lysosomes mediate, at least in part, acute and chronic inflammation in joints.1 2 3 4 This association in no way implies that etiologic agents have been identified in human arthritis, except in such discrete entities as crystal-induced or infectious arthritis. Two main points have been appreciated, however. First of all, it is clear that materials present in lysosomes can provoke inflammation, tissue injury and breakdown of connective tissue. Secondly, it is the normal function of lysosomes, as part of the "vacuolar apparatus" described by DeDuve,5 to extrude enzymes from cells into surrounding tissues.Since many . . .