Systemic juvenile idiopathic arthritis.

Systemic juvenile idiopathic arthritis (sJIA) sets well apart from all the other forms of JIA. Several observations show that sJIA is etiopathogenically different from all the other forms of JIA and has a prominent autoinflammatory component. A major role in the pathogenesis is played by two proinflammatory cytokines, interleukin-6 and interleukin-1. The specific inhibition of these two cytokines is going to change not only the therapeutic approach to the disease but also, presumably, its long term prognosis.