B-cells play an important role in the diagnosis and to some extent the pathogenesis of many
autoimmune diseases. Specific B-cell directed
antibodies are now gaining an increasing role in the management of these diseases. The first antibody target in this regard was CD20, with the development and introduction of
rituximab in the management of B-cell
malignancies as well as
rheumatoid arthritis. A second candidate target is CD22, and the first antagonistic antibody to this B-cell marker is
epratuzumab, which appears to function, in contrast to CD20
antibodies, more by modulation of B-cells than by their depletion capacity. Originally developed for the treatment of
non-Hodgkin lymphoma,
epratuzumab has now been reported to be effective, with a very good safety profile, in two prototype
autoimmune diseases,
systemic lupus erythematosus and primary Sjögren's syndrome. As such, this new investigational antibody may provide distinct
therapeutic effects and may be complementary to the known effects and role of CD20
antibodies.