A Case of Cold Agglutinin Disease Accompanied by Bacterial Pneumonia That Was Treated with Rituximab

Cold agglutinin disease (CAD) is a small group of disorders that is characterized by cold-reactive autoantibodies that bind to erythrocyte carbohydrate antigens, and this causes hemagglutination and complement-mediated hemolysis. Autoimmune hemolytic anemia (AIHA) is an immune disorder that is mediated via auto-antibodies produced by lymphoid B cells against red blood cells. The disorder may be a primary (idiopathic) or secondary disease with an underlying autoimmune disease, a lymphoproliferative disorder or infection. The mainstay of initial treatment is immunosuppression with glucocorticosteroids. For those who do not have satisfactory response to initial glucocorticosteroids or they have a relapse after initially successful treatment, splenectomy or other immunosuppressive agents such as azathioprine, cyclosporine and intravenous immunoglobulin (IVIG) could be the next available options. More recently, rituximab, which is a human-murine chimeric monoclonal antibody specific for the CD20 antigen found on the surface of B lymphocytes, is also available. We report here on the successful use of rituximab for the treatment of a Korean elderly patient with CAD and the patient presented with recurrent AIHA.