Nine patients with anti-neutrophil cytoplasmic antibody-positive vasculitis successfully treated with rituximab

Objectives. Rituximab (RIT) is a monoclonal anti-CD20 antibody, which depletes B-lymphocytes but not plasma cells. RIT is used for treatment of B-cell lymphomas, but has also shown beneficial effects in autoimmune diseases. In this case series RIT was used in anti-neutrophil cytoplasmic antibody (ANCA)-positive vasculitis. Design. Case series with a structured follow-up of treated patients. Setting. Departments of Nephrology and Rheumatology of a university hospital. Subjects. Two women with mycloperoxidase-ANCA-positive microscopic polyangiitis and seven patients (five men and two women) with proteinase 3-ANCA-positive Wegener's granulomatosis. All patients were resistant to conventional therapy or had relapsed repeatedly after cessation of cyclophosphamide (Cyc). Interventions. The cases were treated with intravenous infusions of RIT once a week two times (three cases) or four times (six cases). To prevent formation of antibodies to RIT, mycophenolate mofetil (five patients), azathioprine (one patient), or a short course of Cyc (two patients) were added or allowed to continue. Mainoutcome measures. Remission at 6 months assessed with Birmingham vasculitis activity score. The cases were followed 6-24 months and relapse rate was also noted. Results. Eight of nine patients responded completely and one case responded partially. Pulmonary X-ray improved (four cases), progress of lower extremity gangrene stopped (one case), remission of neuropathy was stable (one patient), renal vasculitis went into remission (two cases), and severe musculoskeletal pain improved (one case). Minor relapse in the nose occurred in two cases. No adverse events or major infections were noted. Conclusion. RIT seems promising and safe in ANCA-positive vasculitis, and controlled studies should be conducted.