Ferritin phagocytosis

The in vitro events of phagocytosis of ferritin and of cationized ferritin by normal eosinophils and the eosinophilic cells of two patients with hypereosinophilic syndrome are described. After one minute of incubation, the cells showed a noticeable pseudopod formation, while after 5 min, ferritin- containing vacuoles were seen in both the normal and the patients' eosinophils. No alterations of the specific granules were observed in cells incubated for 90 min or less. Ferritin was observed in the membrane-bound vacuoles, but not in the specific granules of the cells. There was no difference in phagocytic activity of the patients' eosinophils as compared with the normal eosinophils, as well as between phagocytosis of ferritin and of cationized ferritin.