Chronic cold agglutinin disease (CAD) is a type of autoimmune hemolytic anemia (anemia due to
destruction of red blood cells by abnormal antibodies). Almost all patients also suffer from
cold-induced disturbances of blood circulation. The purpose of this study is to assess the
efficacy and safety of combination therapy with rituximab (an antibody against B lymphocytes)
and fludarabine (a cytotoxic drug) for CAD. Another aim is to try to assess whether these
agents in combination are better than single agent therapy with rituximab.