Whither autoimmunity: the lessons of anti-CCP and B cell depletion.

The most difficult component to understand in autoimmune disease has been the issue of causation. In contrast, there have been enormous gains in improved diagnostics as well as improved therapy. Indeed, the use of biologics have changed the profile of numerous autoimmune diseases. In this issue, we discuss two such aspects. Firstly, we place in perspective the use of anti-citrullinated protein antibodies in rheumatoid arthritis. Second, we discuss the increasing use of B cell depletion in the treatment of autoimmunity. Clinical Reviews in Allergy and Immunology is a unique venue for these themes because it covers the spectrum of allergy through autoimmunity. Indeed, we also present a special paper on the relationships of the hepatitis B virus and autoimmunity. Although the Th1 to Th2 dichotomy is well known to both murine and human immunologists, it is really in the study of specific inflammatory responses that they are correctly placed in the perspective of the continuum of immunopathology.