Clinical Medicine Reviews in Therapeutics

Rheumatoid arthritis (RA) is a chronic, autoimmune disorder primarily affecting the joints but is also associated with many systemic features. Inflammatory cytokines such as IL-6 are abundantly detected in the synovial fluid. IL-6 plays a role in autoimmunity by promoting antibody production and T cell proliferation. The chronicity of inflammation observed in RA can also be partly explained by the effect of IL-6 on leukocyte migration and angiogenesis. Additionally, joint destruction may be mediated by IL-6 dependent osteoclastogenesis. Collectively, these findings prompted the development of an anti IL-6 receptor antibody (tocilizumab). Currently, tocilizumab is indicated for treating patients with moderate to severe RA as monotherapy or in combination with methotrexate, in whom disease modifying anti-rheumatic drugs or anti-TNFs have failed. The side effect profile is manageable but includes infections, decrease in neutrophil, increases in cholesterol and liver transaminases. Tocilizumab has expanded the treatment options of RA.