SESSION TYPE: ILD Cases I
PRESENTED ON: Monday, October 22, 2012 at 01:45 PM - 03:00 PM
INTRODUCTION: Rituximab-induced organizing pneumonia is a rare entity. Several case reports have shown that rituximab is associated with interstitial pneumonia, cryptogenic organizing pneumonia, and acute pulmonary fibrosis. We present a case of rituximab-induced organizing pneumonia successfully treated with prednisone.
CASE PRESENTATION: The patient is 76 year old male with a history of Waldenstrom's macroglobulinemia complicated by a transformation to diffuse large B-cell lymphoma. Treatment with six cycles of rituximab, cyclophosphamide, doxorubicin, oncovin, and prednisone was completed 4 months prior to presentation. A surveillance chest CT showed normal pulmonary parenchyma. Thereafter, rituximab was continued as maintenance therapy for 3 additional cycles when the patient presented with new exercise limitation but without fever, chills, or cough. Repeat chest CT showed new bilateral patchy opacities with mild to moderate centrilobular emphysema. On exam, the patient had a clear chest and an O2 saturation of 96%. The WBC and serum LDH level were in the normal range; the urine legionella antigen was negative. Serum IgM level was normal. A transbronchial biopsy specimen showed new collagen deposition consistent with an organizing pneumonia. Special stains were negative for pathogens or evidence of tumor. One month after starting prednisone, 40mg daily, a repeat chest CT showed significant improvement. The patient’s breathlessness decreased substantially and the prednisone was tapered.
DISCUSSION: Rituximab is an anti-CD20 monoclonal antibody approved for relapsed, refractory, indolent B-cell non-Hodgkin's lymphoma. Although most of the adverse effects associated with rituximab are usually reversible and related to temporary infusion reactions, there have been several case reports linking organizing pneumonia to rituximab therapy. The pathophysiology consists of activation of complement components along with various cytokines, including tumor necrosis factor-α, interleukin (IL)-6 and IL-8. Steroid therapy has been shown to be effective in symptomatic patients with rituximab-induced organizing pneumonia, as seen in the present case.
CONCLUSIONS: Organizing pneumonia is a rare complication of rituximab therapy. Treatment with prednisone has been shown to produce both clinical and radiographic improvement. The incidence and onset remain unknown, but physicians should be aware of the potential pulmonary toxicity complicating rituximab therapy.
1) Maeng CH, Chin SO, et al. A Case of Organizing Pneumonia Associated with Rituximab. Cancer Res Treat. 2007 June; 39(2): 88-91.
2) Biehn SE, Kirk D, Rivera MP, et al. Bronchiolitis obliterans with organizing pneumonia after rituximab therapy for non-Hodgkin's lymphoma. Hematol Oncol. 2006 Dec;24(4):234-7.
DISCLOSURE: The following authors have nothing to disclose: Singwu Law, Young Kwak, Kevin Felner, Harold Sauthoff, John Hay, Robert Smith
No Product/Research Disclosure InformationNYU, New York, NY