The relation of experimental arthritis to the distribution of streptococcal cell wall fragments.

The intraperitoneal injection of peptidoglycan-carbohydrate fragments from Group A streptococci produces a chronic, polyarticular, erosive synovitis in rats. The cell wall material accumulates rapidly in the liver, spleen, and lymph nodes, where it causes little injury. At the same time, selective localization and persistence of the material in the synovial and periarticular tissues occurs. Its presence in the joint is associated with acute and recurrent inflammation with focal synotivitis, pannus formation, joint destruction, and ankylosis. Cell wall fragments become localized in the synovial and periarticular tissues at a time when there are leukocytes in the bloodstream, which appear to contain the material. During this early phase vascular lesions appear in the synovium and in periarticular tissues with collections of fibrin, neutrophils, macrophages, and cell wall fragments near the venules and capillaries. Recurrent episodes of inflammation and joint injury, associated with persistent cell wall antigen within macrophages, were observed over a period of 90 days.