[Visceral lesions in hypereosinophilia]

The hypereosinophilic syndrome is an ill-defined nosological entity with predominant risks of cardiac and/or neurological lesions. In the light of new data on the effector cytotoxic effects of eosinophils, we have tried to establish new criteria of severity by purifying the circulating eosinophils of 14 patients with hypereosinophilic syndrome and testing their toxicity. This study has revealed the existence of low density ("hypodense") eosinophils with potential cytotoxicity in vitro. The worst clinical forms of the syndrome were observed in the group of patients with positive eosinophil toxicity tests. The significance of these cellular changes (hypodensity, eosinotoxicity) and their relationship with the clinical manifestations are discussed.