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Autoantibodies in rheumatoid arthritis

Autoantibodies are a characteristic feature of autoimmune diseases. Although the exact pathogenetic role of autoantibodies is in general not known, they are very often useful for diagnostic purposes. Rheumatoid arthritis (RA) is a chronic autoimmune disease primarily affecting the joints. RA is a heterogeneous disease that encompasses several disease subsets with probable differences in underlying pathophysiology. Via a final common inflammatory pathway these different pathophysiological pathways might lead to a similar clinical presentation of arthritis. The best-known subdivision in RA is between autoantibody positive and autoantibody negative RA, which differ in both risk factors and clinical outcomes. This chapter focuses on the role of autoantibodies in the pathophysiology of RA. First, the relation between autoantibodies and known risk factors for RA will be discussed. Thereafter, the specific characteristics of the autoantibody response and the pathogenic potential of the different autoantibodies are reviewed.