Induction of remission by B lymphocyte depletion in eleven patients with refractory antineutrophil cytoplasmic antibody-associated vasculitis

Objective. To assess the clinical effects of rituximab therapy in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Methods. The study group comprised 11 patients who had active AAV despite receiving maximally tolerated doses of cyclophosphamide or had contraindications for cyclophosphamide use. All patients had ANCA reactive against proteinase 3. The patients received rituximab infusions and glucocorticoids to induce remission. Three patients also received plasma exchange. No other immunosuppressive agents were used. Glucocorticoids were tapered as soon as control of disease activity was achieved. Disease activity was monitored using the Birmingham Vasculitis Activity Score, modified for Wegener's granulomatosis. Results. Rituximab therapy was well tolerated by all patients, and adverse events were rare. Following the rituximab infusions, circulating B lymphocytes became undetectable, and ANCA titers decreased significantly. Remission was achieved in all patients and was maintained while B lymphocytes were absent. Conclusion. The ability to achieve stable remissions with rituximab in patients with AAV refractory to conventional therapy suggests that B lymphocyte depletion may be a safe, effective, mechanism-based treatment modality for treatment of patients with these conditions.