Pathogenesis and treatment of ANCA-associated vasculitides.

Recent studies have increased our insight into the pathogenesis of ANCA-associated vasculitis (AAV). Although many data from in vitro and in vivo experimental studies support the pathogenic role of the autoantibodies, cellular immunity seems involved as well. Besides, an amplification loop via the alternative pathway of complement is apparent. These new insights make a more targeted therapeutic approach possible. In particular, the B-cell depleting antibody rituximab has been shown non-inferior to cyclophosphamide for induction of remission, and even superior in patients with relapsing disease being positive for PR3-ANCA. Rituximab is also superior to cyclophosphamide for maintaining remission. Blocking the C5a-receptor seems promising as well as an alternative for high dose corticosteroids during induction of remission.