Acute monocytic leukemia cell isoferritin.

Ferritin was purified from acute monocytic leukemia cells, and its biochemical and immunological properties were investigated. The iron content of acute monocytic leukemia cell ferritin was extremely low, and this ferritin migrated slightly faster than normal adult liver ferritin on immunoelectrophoresis and polyacrylamide gel disc electrophoresis. Isoelectric focusing in polyacrylamide gel showed predominantly acidic isoferritins. This was considered to characterize the nature of isoferritin from normal monocytes or to be the result of neoplastic change of monocytes. Immunologic studies failed to recognized any antigenic differences between isoferritin from acute monocytic leukemia cells and that from normal adult liver. Therefore, selective quantitation of acute monocytic leukemia cell isoferritin, if any in leukemic sera, by means of immunoassay was considered difficult.