Leukocyte Kinetics in Hematologic Disorders Studied by DNA-Phosphorus Labeling

Leukocyte physiology in the normal and in hematopoietic disease states in humans has been studied by DNA-P labeling with inorganic P³². In the normal there is a post-mitotic granulocyte reservoir in marrow about 17 times the size of the intravascular compartment. Progress through this reservoir is orderly and requires about 6 days. Some 1-2 x 10¹¹ cells daily are released from it into the blood. In polycythemia vera there is an increased production of granulocytes. DNA-P labeling in patients with chronic lymphocytic leukemia occurs at a very low level and is compatible with a very slow rate of cell renewal. In one patient with chronic lymphocytic leukemia, no disturbances in kinetics caused by a dose of 20 µc. of P³²/Kg. were detected during the time of the study. Although a progressively rising concentration of label in circulating leukocyte DNA was found in patients with chronic granulocytic leukemia, without the lag suggesting a distinct marrow phase, it is concluded that the blood and extravascular leukopoietic compartments cannot be a single compartment. An essentially normal curve is obtained after induction of a complete remission with busulfan.