Pilot Study of Short-Course Glucocorticoids and Rituximab for Treatment of ANCA-Associated Vasculitis

Inclusion Criteria: * Patients ages 18-85 years old * Diagnosis of GPA or MPA according to the definitions of the Chapel Hill Consensus Conference * New diagnosis or disease flare with a Birmingham Vasculitis Activity Score/Wegener's granulomatosis (BVAS/WG) of \> 3 Exclusion Criteria: * Renal disease in patients with PR3-ANCA as defined by any of the following: * Urinary red blood cell casts * Biopsy-proven glomerulonephritis * Increase in serum creatinine of \>30% over baseline * Severe renal disease in patients with MPO-ANCA as defined by both of the following: * Urinary red blood cell casts or biopsy-proven glomerulonephritis * Estimated glomerular filtration rate \< 30 ml/min/1.73m2 * Diffuse alveolar hemorrhage requiring ventilatory support * GC treatment for longer than 14 days prior to enrollment unless patient has been on a stable maintenance dose of prednisone at the time of the flare * Daily oral cyclophosphamide within 1 month prior to enrollment * Completed a remission induction course of cyclophosphamide or rituximab within 4 months of enrollment * Hepatitis B infection * HIV infection * History of anti-GBM disease * Other uncontrolled disease, including drug and alcohol abuse, that may interfere with the study * Pregnancy or breastfeeding * History of severe allergic reactions to human or chimeric monoclonal antibodies