Cytokines and the Pathophysiology of Bone Erosions in Rheumatoid Arthritis

Rheumatoid arthritis is an inflammatory joint disease in which the chronic synovitis leads to bone and cartilage degradation. Proinflammatory cytokines such as interleukin-1 (IL-1) and tumor necrosis factor alpha are key factors in this process. The specific control of the action of these cytokines can be obtained with blocking antibodies, soluble receptors and receptor antagonists. Many of these products are now in clinical investigation. Some of the anti-inflammatory cytokines such as IL-4, IL-13 and IL-10 appear to affect more directly the consequences of inflammation, reducing destruction and inducing repair. Modulation of cytokine production by the rheumatoid synovitis appears to represent a potential way to control local bone degradation.