Circulating Granulocytic and Erythroid Progenitor Cells in Chronic Granulocytic Leukaemia

Abstract

A standard methyl cellulose method was used to assay erythroid progenitor cells in the blood of 35 patients with untreated CGL [chronic granulocytic leukemia] and of 18 normal controls. In 28 patients, granulocyte/monocyte committed progenitor cells (CFU-c) were simultaneously assayed by an agar method. Circulating erythroid burst-forming units (BFU-e) in CGL were increased above normal by a factor of about 180; CFU-c were increased by a factor of about 9000. Both BFU-e and CFU-c numbers were linearly related to the total leukocyte count in individual patients but not to numbers of circulating blast cells. There was a positive correlation in individual patients between CFU-c and BFU-e numbers. Circulating BFU-e and erythroid colony-forming cells (CFU-e) were unable to proliferate in vitro in the absence of erythropoietin. Erythroid progenitor cells are involved in the clonal expansion that characterizes CGL, but apparently to a lesser extent than are granulocyte/monocyte progenitor cells.