Monoclonal immunoglobulin rescue from a patient with chronic lymphocytic leukemia and autoimmune hemolytic anemia

In order to test whether autoimmune hemolytic anemia in a patient with chronic lymphocytic leukemia was due to autoantibody production by the neoplastic clone, somatic cell hybrids were constructed between the patient's leukemic cells and a mouse myeloma line. Light-chain- restricted human immunoglobulin was secreted by 4 of 11 of the established hybrid lines. No binding of this immunoglobulin to red cell surface antigens could be detected. Thus, we conclude that the autoantibody in this patient represented a concomitant reactive response and was not the product of the malignant clone of B cells.