hematology and oncology
Eosinophil Production and Function
Introduction
Eosinophils are granulocytes (white blood cells that contain granules in their cytoplasm) derived from the same progenitor cells as monocytes-macrophages, neutrophils, and basophils. They are a component of the Innate immunity . Eosinophils have a variety of functions, including Defense against parasitic infections Defense against intracellular bacteria Modulation of immediate hypersensitivity reactions Eosinophils are especially important in defense against parasitic infections. However, although eosinophilia commonly accompanies helminthic infections and eosinophils are toxic to helminths in vitro, there is no direct evidence that they kill parasites in vivo. Although they are phagocytic, eosinophils are less efficient than neutrophils in killing intracellular bacteria. Eosinophils may modulate immediate hypersensitivity reactions by degrading or inactivating mediators released by mast cells, such as histamine, leukotrienes (which may cause vasoconstriction and bronchoconstriction), lysophospholipids, andheparin. Prolonged eosinophilia may result in tissue damage by mechanisms that are not fully understood. 