Deficient superoxide-generating activity and its activation of blood monocytes in cancer patients

Superoxide (O2-)-generating activity of blood monocytes, the precursors of macrophages, from patients with advanced cancer and/or infection was studied. Monocytes from normal subjects generated 0.288 +/- 0.022 nmol O2-/min/10(5) cells (mean +/- S.E.M., n = 36) after sequential stimulation with cytochalasin E and wheat germ agglutinin. Monocytes from 69 non-infected adult patients with advanced malignancy of the stomach, esophagus and liver, and 7 pediatric patients with neoplastic disease released significantly less O2- than those from normal subjects (0.176 +/- 0.015, P less than 0.005). Infection increased the activity about 4-fold in patients with malignancy compared to non-infected cancer patients. These results suggest that monocytes of cancer patients are defective in secreting O2-, though the activity may be stimulated by infection.