Pneumocystis jiroveci pneumonia following rituximab treatment in Wegener's granulomatosis

Abstract

Wegener's granulomatosis (WG) is a devastating small-vessel vasculitis in children. Standard treatment consists of immunosuppressive medications with cyclophosphamide potentially associated with significant infectious side effects, including Pneumocystis jiroveci pneumonia (PCP). Recently, rituximab, a monoclonal antibody against B cells, has successfully been used in refractory disease. We describe the first pediatric patient with refractory WG with sinus and lung disease who developed PCP 6 months after treatment with rituximab, while being treated with methotrexate and prednisone. This 9-year-old child had no CD20+ B cells at time of infection, with normal lymphocyte and CD4 counts. This study provides a review of the published literature, including current protocols, which suggest chemoprophylaxis only in WG patients receiving T cell-targeted immunosuppression such as cyclophosphamide. However, clinical and laboratory evidence points toward a possible role of B cells in the defense against PCP. Routine PCP chemoprophylaxis should be strongly considered in patients with WG treated with rituximab.