Motility and oxidative metabolism of normal polymorphonuclear leukocytes in acute non-lymphoid leukemia in complete remission

Polymorphonuclear leukocytes (PMN) from 11 patients with acute non-lymphoid leukemia (ANLL) in complete remission and off therapy for at least 22 months were studied for their oxidative metabolism and motility. In all patients, PMN motility tests revealed no consistent abnormality, whereas cells from 2 patients showed a selective impairment of oxidative metabolism, as assessed by the low capacity to reduce nitroblue tetrazolium and/or to generate chemiluminescence when stimulated with phorbol myristate acetate. No morphological change was detectable in PMN from these patients. However, the functional alterations appeared related to an early tendency to relapse, as both patients developed an acute phase after 5 and 9 months from testing, respectively. This suggests that abnormal PMN may circulate in ANLL patients in complete remission in spite of a normal differential count and that functional studies may be useful for detecting such a population.