The immune system and new therapies for inflammatory joint disease

This article provides an overview of the immune system with a specific focus on the role of biologic therapies in treating the consequences of an altered immune response as seen in rheumatoid arthritis (RA). Cytokines are powerful chemical messengers that have a significant role to play in activating an inflammatory response. Two dominant cytokines have been identified as crucial in the inflammatory process that can be seen in RA-tumour necrosis factor alpha (TNFalpha) and interleukin-1. The term 'biologic' is used to describe biologically engineered therapies that are specifically designed to prevent pro-inflammatory cytokines inducing an inflammatory response. Research trials and now clinical practice have clearly demonstrated a significant benefit to patients receiving biologic therapies. The responsibility of the practitioner is to ensure a sound knowledge of biologic therapies, to understand the essential aspects of care and to recognize the importance of guidance documents available to support management and, ultimately, the long-term provision of safe and effective administration of these therapies.