Author Description

The eosinophil was identified more than a century ago, and at first dismissed as, at best, just another polymorphonuclear cell. Later, it was considered to play a pivotal role in countering the potentially damaging effects of mast cell degranulation via the production of neutralizing enzymes. Reappraisal followed with the demonstration of toxic effects of the eosinophil's cationic proteins. Instead of a cell with predominantly beneficial properties, the eosinophil was seen as actively contributing to the pathogeneisis of chronic inflammatory diseases such as asthma.