To be, or not to be, an eosinophil: that is the ???

摘要

In the more than 100 years following Paul Ehrlich's 1879 identification of the eosinophil, the compendium of diseases and idiopathic syndromes characterized by blood or tissue eosinophilia grew by leaps and bounds, while our understanding of the functional roles of the eosinophil in innate immunity and host defense, allergic responses, tissue injury/repair, and remodeling/fibrosis lagged far behind, being addressed in only the past 30 or so years.2 Initial studies characterized the unique biologic characteristics of blood and tissue eosinophils, their preformed secondary granule proteins, and inducible lipid, oxidative, and cytokine products, focusing on the eosinophil's proinflammatory and cytotoxic potential in the pathogenesis of allergic, parasitic, and a variety of idiopathic eosinophil-associated syndromes. Recognition of the eosinophil as an effector cell in asthma pathogenesis fueled an initial surge in eosinophil interest, while an "epidemic" of eosinophil myalgia syndrome from ingestion of tainted L-tryptophan, and more recent identification of the food-allergic disease eosinophilic esophagitis, markedly increased clinical interest and public awareness of this granulocyte.