[Interleukin-6 as a pathogenic factor of systemic-onset juvenile idiopathic arthritis]

Systemic-onset juvenile idiopathic arthritis (JIA) is a subtype of chronic childhood arthritis of unknown cause, manifested by spiking fever, erythematous rash, arthritis, pericarditis, and hepatosplenomegaly. It has been believed a disease developed due to an excessive production of pro-inflammatory cytokines, especially interleukin (IL)-6. We organized trials of a new biologic response modifier, Toclizimuab, anti-IL-6 receptor monoclonal antibody, to patients with systemic-onset JIA. Tocilizumab directs to solely IL-6 receptor, and is called as a one-point hit drug. We successfully administered Tocilizumab to stabilize the inflammation, and inflammatory symptoms and signs of the patients were abruptly gone. Previously, corticosteroids were the only life-saving drugs, but we proved Tocilizumab will be the possible alternative for treating these children. Basic science will help us to save the children, and clinical science also will promote the basic science in turn.