Neutrophil function during immunotherapy for acute myelogenous leukemia in remission.

In acute myelogenous leukemia the remission time may be prolonged by adding immunotherapy to maintenance chemotherapy. The mechanisms for this action are nuclear. We have studied polymorphonuclear neutrophil (PMN) functions in 18 patients with acute myelogenous leukemia in remission treated either with chemotherapy (CT; n = 7) or the combination of chemotherapy and immunotherapy (CT + IT; n = 11); in addition comparisons were made with healthy controls. PMN migration under agarose stimulated by a bacterial factor from Escherichia coli was significantly lower in both patient groups compared with healthy controls. When migration was stimulated with serum, it was low only in the CT + IT group. The capacity of PMNs to kill Staphylococcus aureus was reduced in the CT + IT group but normal in the CT group. The adherence to nylon fibers was higher in the CT + IT group compared to the controls and the CT group. There was no difference in chemiluminescence during phagocytosis between the two groups. Thus, there was no indication that monthly maintenance CT essentially impaired the PMN functions investigated. However, IT was associated with impairments of migratory and bactericidal functions and enhanced adherence of neutrophils. The mechanisms and clinical significance of this remain nuclear.