Correspondence to

Cyclophosphamide has greatly improved prognosis in anti-neutrophil cytoplasmic autoantibody-associated vasculitis (AAV) and proliferative lupus nephritis (LN). However, the side effects of long-term cyclophosphamide treatment are considerable prompting a search for alternatives to cyclophosphamide. For maintenance treatment in AAV, azathioprine is the preferred drug with methotrexate as an alternative in the case of intolerance to azathioprine. Data on mycophenolate mofetil (MMF) for the induction of remission in AAV are being awaited, but rituximab appears as effective as cyclophosphamide in newly diagnosed patients with AAV, and is probably even better for relapsing patients, while the possibility of maintenance treatment with intermittent low-dose infusions of rituximab is being explored. In LN, low-dose intravenous cyclophosphamide is as effective as high-dose cyclophosphamide for the induction of remission, with azathioprine being used for maintenance treatment. MMF can be used in the case of intolerance to cyclophosphamide and might be the first choice in black and Hispanic patients. In the case of intolerance to both cyclophosphamide and MMF, azathioprine with pulses of methylprednisolone can be used. Here, the role of rituximab has not been established. In conclusion, alternatives are available for cyclophosphamide both in AAV and proliferative LN