Effects of anakinra on clinical and radiological outcomes in rheumatoid arthritis.

Interleukin 1 (IL1) plays a central part in the pathophysiology of rheumatoid arthritis (RA). 2 The IL1 gene family includes IL1α, IL1β, and IL1 receptor antagonist (IL1Ra). IL1α and IL1β are both agonist molecules. There are two distinct IL1 receptors, designated type I (IL1RI) and type II (IL1RII). IL1 binding to IL1RI results in signal transduction and cell activation. IL1Ra is the third member of the IL1 gene family. The agonistic effects of IL1 are partially blocked by the interaction between IL1Ra and IL1RI. When IL1Ra binds to IL1RI, it blocks the binding of IL1α and IL1β and inhibits signal transduction. Recombinant human IL1Ra, anakinra, has been approved for the treatment of patients with rheumatoid arthritis (RA).