Charcot-Leyden crystals: solving an enigma

Abstract

In this issue of Blood , Ueki et al elegantly demonstrate the active formation of Charcot-Leyden crystals (CLCs) during eosinophil cytolysis. 1 After confirming the association of CLC deposition with eosinophilic inflammation and eosinophil plasma membrane disruption in tissue sections by light and electron microscopy, Ueki et al used a combination of sophisticated imaging techniques, including immunofluorescent time-lapse photography, to follow the course of CLC formation in vitro in response to a variety of stimuli that induce eosinophil extracellular trap death (EETosis). The association of CLC with the disintegration of eosinophils was proposed as early as the 1940s, 2 and agents, such as Aerosol MA, which disrupt the integrity of eosinophils, were subsequently shown to promote CLC formation in vitro in the surrounding media. 3 Ueki et al provide the first definitive evidence that CLC formation is energy-dependent and closely tied to the process of EETosis (see figure).