Studies on abnormal polymorphonuclear neutrophils in acute myelogenous leukemia: clinical significance and changes after chemotherapy.

In patients with acute myelogenous leukemia (AML), 34 out of 35 patients (97%) had cytochemically abnormal polymorphonuclear neutrophils (PMN). Some interesting regularity was noted in the appearance of cytochemical abnormalities of the PMNs. When peroxidase (PO) activity was low, both alkaline phosphatase (AP) and chloroacetate esterase (CAE) activities were also low (group A). When PO activity was normal, if AP activity was low, CAE activity tended to be high (group B) and if AP activity was high, CAE activity tended to be low (group C). Complete remission rate of group B (65%) seemed to be better than that of group C (20%) and group A (25%) although the differences was not statistically significant. In these patients, the number of peripheral leukemic blasts and PMNs showed a significant positive correlation (r = 0.69, p less than 0.005). Furthermore, patients with higher circulating PMN counts (more than 2 X 10(9)/L) had a significantly worse prognosis than patients with lower counts (p less than 0.05). These rather unexpected findings strongly suggest that cytochemically abnormal PMNs are progeny of AML blasts. The change in the proportion of abnormal PMNs associated with chemotherapy were studied in 21 patients during the remission induction period. Abnormal PMNs disappeared from the circulation in patients who achieved complete remission. In contrast, abnormal PMNs persisted throughout the remission induction period in patients who failed to achieve complete remission.