The future of the IL-1 receptor antagonist anakinra: from rheumatoid arthritis to adult-onset Still's disease and systemic-onset juvenile idiopathic arthritis.

IL-1 receptor antagonist (IL-1Ra) is a naturally occurring IL-1RI-binding molecule that blocks the biologic effects of the proinflammatory cytokine IL-1. A recombinant form of human IL-1Ra, anakinra (Kineret), has been approved for use in rheumatology initially to manage rheumatoid arthritis (RA) patients that are refractory to more conventional forms of treatment. This review summarizes the experience with anakinra in the treatment of patients with rheumatic diseases emphasizing its beneficial effects in novel applications. English-language trials of anakinra were searched using MEDLINE and abstracts from rheumatology scientific meetings. In the treatment of patients with RA anakinra is effective but inferior to TNF-alpha blocking agents. Over the last few years it has become increasingly evident that anakinra is highly effective and safe in patients with systemic-onset juvenile idiopathic arthritis, adult-onset Still's disease, hereditary autoinflammatory syndromes, Schnitzler's syndrome and recently in gouty attacks.