Autoimmunity - Rheumatoid Arthritis

This chapter discusses autoimmunity in rheumatoid arthritis (RA). The clinical presentation of RA is heterogeneous with a wide spectrum of age of onset, degree of joint involvement, and severity. Although the cause of RA remains unknown, advances in molecular technology have facilitated identification of cell subsets and cytokines contributing to the inflammatory and destructive components of the disease. The majority of biologic markers of potential value in the diagnosis and assessment of outcome in RA are measured in peripheral blood or urine. Although, in general, cytokines and immune cell subsets within the peripheral blood compartment are not measured clinically they are considered to be important in the pathogenesis of RA. In terms of RA diagnosis, rheumatoid factors remain the sole serological measure included in the widely used American College of Rheumatology classification criteria for RA. However, there is currently increasing interest in the measurement of antibodies to cyclic citrullinated peptides (anti-CCP) as a more specific marker of RA. The chapter discusses principles behind the measurement of biologic markers and the markers under investigation in the diagnosis and assessment of outcome in RA. © 2005 Elsevier Ltd. All rights reserved.