New therapeutic targets in ANCA-associated vasculitis.

Anti-neutrophil cytoplasm antibody (ANCA)- associated vasculitis (AAV) is a rare systemic auto-immune disease characterised by necrotizing inflammation of predominantly small blood vessels and the presence of circulating ANCA directed against myeloperoxidase (MPO) or proteinase-3 (PR3). Current treatment strategies for severe disease, supported by the findings of several well-coordinated randomised control trials, aim to induce remission with high-dose glucocorticoids and either rituximab or cyclophosphamide, followed by relapse prevention with a period of sustained low-dose treatment. This approach has dramatically improved outcomes in AAV, however a significant proportion of patients experience serious treatment-related side effects or suffer relapse. Recent advances in our understanding of disease pathogenesis has led to the identification of novel therapeutic targets which may address these problems, including those directed at the aberrant adaptive autoimmune response (B and T cell directed treatments) and those targeting innate immune elements (complement, monocytes, neutrophils). It is anticipated that these novel treatments, used alone or in combination, will lead to more effective and less-toxic treatment regimens for patients with AAV in the future