Metabolic heterogeneity of eosinophils from normal and hypereosinophilic patients

Eosinophils, which may be associated with allergic, parasitic, or neoplastic disease, have a potent oxidative burst that may be activated by particulate or soluble stimuli. Eosinophils from normal persons and patients with hypereosinophilia were compared with respect to their ability to produce the active oxygen product, superoxide anion. Normal eosinophils produced large amounts of superoxide anion under resting conditions (0.53 ± 0.15 nmoles cyto-c/10⁵ eos/hr) and when stimulated by preopsonized zymosan (0.85 ± 0.10 nmoles cyto-c/10⁵ eos/hr) or phorbol myristate acetate (PMA) (2.38 ± 0.46 nmoles cyto-c/10⁵ eos/hr). Considerable variation was observed in superoxide production by eosinophils from patients with hypereosinophilia. Eosinophils from a group of four patients with hypereosinophilia associated with neoplastic disease produced less superoxide anion than normal eosinophils when stimulated by preopsonized zymosan or PMA (p = 0.05). Eosinophils from a group of 5 patients with other causes of hypereosinophila produced more superoxide anion than normal eosinophils when stimulated by PMA (p = 0.01). These studies demonstrate metabolic heterogeneity of eosinophils from patients with hypereosinophilia, and further emphasize that normal eosinophils and eosinophils from hypereosinophilic patients are not functionally equivalent.