RNAi in arthritis: prospects of a future antisense therapy in inflammation.

Rheumatoid arthritis is a chronic autoimmune disease of unknown etiology that is characterized by chronic systemic inflammation, mainly affecting the joints, leading to subsequent destruction of the cartilage and bone. RNA interference (RNAi) has been used as a remarkable new research tool to control gene expression and is ultimately envisioned to be useful in clinical treatments. The potential application of RNAi-based therapy in rheumatoid disorders is evaluated. The first successful attempts at TNFalpha silencing by local and systemic delivery of small interfering RNA in experimental arthritic models are discussed. In addition, RNAi and current biotherapies used in the clinic are compared and contrasted.