Phagocytic ability of polymorphonuclear cells and macrophage is not decreased in aged bed ridden patients

The phagocytic ability of polymorphonuclear cells and macrophages from aged, bed ridden patients was investigated. Phagocytosis of carbon in aged bed ridden patients did not differ from that of young controls, and extent of upregulation of granulocytes phagocytosis in response to elevation of incubation temperature was also similar between the two groups. Morphological changes of macrophages in response to ingestion of colloidal carbon was more prominent in young controls. These data suggest that a depressed phagocytosis is not an important factor in the increased susceptibility to infections of aged bed ridden patients, although the reactivity of macrophages may be more closely related to the infection defence.