[Cold agglutinin disease--initial description in erythroblastosis and polycythemia vera]

The cold agglutinin disease is a hemolytic anemia induced by antibodies. Beside other etiological factors the disease is associated with tumors. In this paper cold agglutinin disease combined with erythroblastosis and combined with polycythemia vera is presented at the first time. In one case malignant proliferation followed the appearance of cold agglutinin antibodies. Blood transfusion, plasmapheresis, corticosteroids and chlorambucil were not successful. In the other case antibodies were temporarily expressed after a long time of malignant proliferation. Blood transfusion and corticoids were sufficient. Production of antibodies as a kind of tumor defence is discussed as reason for hemolysis. "Cross reacting antigenity" between normal and malignant erythrocytes is postulated.