Ora Singer, W. Joseph McCune

The antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitides are a group of rare systemic diseases. The past several years have seen major therapeutic advances in the treatment of granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). The success rate in induction of remission is high, but reducing the high incidence of relapses remains a therapeutic challenge. Studies have shown no improvement in relapse rates in GPA and MPA over the past 2 decades. This has prompted a recent focus on therapeutic strategies to maintain remission in these relapsing diseases. Low-dose rituximab (RTX) at fixed intervals has been shown superior to azathioprine for maintenance of remission. Despite this advance, longer follow-up periods have shown late-stage relapses with withdrawal of therapy suggesting a possible need for longer treatment regimens. Evaluation of prognostic indicators is also helpful in stratifying patients who might be more likely to relapse or to respond to a particular therapy. Results from recent research have significantly advanced our approach to prevention of relapses in GPA and MPA. Newer maintenance agents have shown benefit in maintenance of remission and relapse-free survival.