Rituximab in refractory antineutrophil cytoplasmic antibody-associated vasculitis: what is the current evidence?

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is recognized as a chronic, relapsing and potentially fatal disease. Cyclophosphamide and steroids remain the mainstay of treatment of AAV [ 1 ]. Unfortunately, in up to 10% of patients, disease remains refractory despite conventional therapy [ 1 ]. In addition, conventional therapy has some serious side effects and hence limits its long-term use. For these refractory patients and those intolerant of conventional therapy, there are limited therapeutic options. B-lymphocytes have been implicated in the pathogenesis of AAV, by being the precursors of plasma cells (PCs), which produce ANCA [ 2 ] and in the formation of granuloma in Wegener's granulomatosis (WG) [ 3 ]. Apart from the important role in antibody production, B-cells can also affect other aspects of the immune regulation such as immune response regulation, antigen presentation and cytokine production. This has been recognized in autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus, where the disease process is B-cell dependent and antibody independent [ 4 , 5 ].