Cytokines in rheumatic diseases

IL-1 and related cytokines have multiple biologic activities relevant to the rheumatic diseases. In addition to mediating inflammatory and immune responses, these proteins regulate many aspects of connective tissue metabolism. The cytokines interact in complex cascades: because of this, and various technical reasons, the exact role of cytokines in the pathogenesis of rheumatic diseases remains uncertain. However, considerable experimental data suggest that the abnormal regulation of cytokines contributes to such siseases as inflammatory arthritis, systemic lupus erythematosus, scleroderma, and dermatomyositis. Animal models of these diseases have contributed to understanding the role of cytokines in pathogenesis. Furthermore, drugs useful in treating these diseases affect cytokine pathways; some cytokines, their antagonists, or related substances have been used therapeutically to treat rheumatic diseases. The therapeutic use of these agents will likely increase as knowledge about the role of cytokines in the pathogenesis of rheumatic diseases expands.