Studies of the changes in leukocyte alkaline phosphatase following pyrogen stimulation in chronic granulocytic leukemia.

Bi, PASQUALE E. PEIIILLIE T HE ALKALINE PHOSPHATASE ACTIVITY of the granulocytes (LAP) in patients with chronic granulocytic leukemia (CGL) usually is not increased following stimulation by either adrenocortical hormones or pyrogen, whereas the LAP of normal subjects and most patients with nonleukemic disorders shows a definite rise following similar stimulation. ’ An occasional patient with well-documented CCL, however, will demonstrate an increased LAP during acquired infection or following either steroid or pvrogen administration.4 In nonleukemic subjects it has not been possible to determine with certainty the mechanisms leading to the rise in LAP which follows either acquired infections or the administration of corticosteroid or pyrogen. It is not clear whether the rise in LAP is due to the enhancement of enzyme synthesis by the mature circulating cells, or whether such stimuli exert their prime effect on the less mature marrow granulocyte precursors with subsequent delivery Of such cells into the circulation.’2 It has been suggested that the rise in LAP following pyrogen stimulation may be due to an initial selective sequestration of enzyme rich circulating cells followed by a sul)sequent redelivery of such cells into the circulation.7 In addition to these basic prol)lems it is uncertain whethier in CCL the appearance of granulocytes with increased LAP denotes the presence of a dual population of normal and leukemic cells or represents a temporary alteration in an aberrant biochemical process of the leukemic cell.25 This report concerns further attempts to elucidate the mechanism of LAP change in the granulocytes of a patient with CCL who transiently increased his LAP concomitant with an acute bacterial infection. Following recovery from the infection, gram negative endotoxin was injected in order to restimulate LAP. A histochemical method for demonstrating LAP seemed most suitable for the proposed study since it was felt that the appearance of granulocytes with increased LAP would serve as unique natural markers in the setting of the reduced enzyme activity present imi the patient’s granulocytes prior to stimulation.