Treatment of antineutrophil cytoplasmic antibody associated vasculitis: a systematic review

Immunosuppressive therapies for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis have greatly advanced patient survival but have turned ANCA-associated vasculitis (AAV) into chronic, relapsing disorders. Long-term treatment and disease-related morbidity are major threats. The last decade has seen a collaborative international effort to determine effective treatment.

To analyze the reported evidence on AAV therapy in order to provide physicians with a rational approach for dealing with various clinical scenarios.

We searched English-language articles on the medical treatment of AAV published between 1966 and March 2007 using MEDLINE. Articles from the reference lists of the most relevant articles retrieved were also analyzed.

Studies of current available drug treatments or medical interventions for patients with AAV were included. Duplicate publications, case reports, and uncontrolled trials and series including fewer than 10 patients were excluded.

We included 2 meta-analyses, 20 randomized controlled prospective trials, and 62 uncontrolled trials with more than 10 patients or observational studies. Outcome measures and treatment protocols were heterogeneous across trials. Cotrimoxazole can be used alone or in combination with corticosteroids to induce and maintain remission in cases of isolated upper respiratory tract involvement. To induce remission, methotrexate plus corticosteroids can be used instead of cyclophosphamide for patients with generalized, non-organ-threatening disease. When methotrexate is used as maintenance therapy, the likelihood of relapse is high and rigorous monitoring is mandatory. Pulse cyclophosphamide with corticosteroids can be used to induce remission in patients with generalized organ-threatening disease. The combination of azathioprine and daily prednisone is effective in maintaining remission. Plasma exchange is at present the best complement to immunosuppressants in advanced renal disease. In Churg-Strauss syndrome, treatment can be started with high doses of corticosteroids, tapering them when the clinical situation improves. In patients with a high risk of death, cyclophosphamide should be introduced.

Although AAV therapies should be tailored to the patient's specific clinical situation, evidence for treatment of several disease states is lacking. There is a need for safer and more effective drugs.