Targeting the B cell in vasculitis.

The treatment of severe vasculitides, such as antineutrophil cytoplasmic autoantibodies (ANCA)-associated vasculitis, is associated with both short- and long-term toxicities that limit its use in paediatric patients and is complicated by refractory and relapsing disease that requires increased exposure to these toxic therapies. B cells have been implicated in the pathogenesis of autoimmune diseases, including vasculitis, and represent a potential target for new therapies that may have a more acceptable toxicity profile. The use of rituximab, a biologic therapy directed against B cells, has provided valuable insight into the potential role of B-cell targeted therapies for vasculitis. Rituximab appears to be a potentially useful treatment for vasculitis in adult patients, but randomized evidence comparing it to cyclophosphamide in terms of both efficacy and toxicity is lacking, as is long-term safety data. Several other B-cell-directed therapies are in development and may offer rational alternatives or adjunctives to traditional treatments.