STUDY OF RELEASE OF EOSINOPHIL CATIONIC PROTEINS (ECP AND EPX) IN THE HYPEREOSINOPHILIC SYNDROME (HES) AND OTHER HYPEREOSINOPHILIC CONDITIONS

BACKGROUND: Up to date, the etiology and the pathogenesis of HES are still unknown and particularly it is unclear why eosinophils in HES are more aggressive towards tissues than in other eosinophilic conditions. METHODS: We assessed the cationic proteins ECP and EPX serum concentrations, their in vitro release from polymorphonuclear cell culture, and the monoclonal antibodies EG1 and EG2 in 3 patients with HES, 6 patients with other hypereosinophilic conditions and 20 healthy control subjects. RESULTS: Serum ECP and EPX concentrations were higher in eosinophilic patients than in healthy subjects. Hypereosinophilic patients had more EG2+ cells than healthy subjects, but EG2+ rate failed to differentiate HES from other hypereosinophilic conditions (p = 0.074). Moreover, the release in vitro of ECP and EPX was significantly higher in HES patients (p < 0.05). CONCLUSIONS: Our preliminary results seem to suggest the importance of functional data, such as ECP and EPX release, in differentiating HES from other hypereosinophilic diseases. Particularly, ECP and EPX release in vitro is higher in cell cultures from HES patients than from patients with other hypereosinophilic conditions.