[Disorders with eosinophilia, treatment of hypereosinophilic syndrome].

Eosinophilia may be associated with reactive conditions and with clonal disorders of the hematopoietic cells. The hypereosinophilic syndrome takes an intermedier place in this group. In this disease a sustained eosinophilia with end organ damage can occur. The author summarized the diagnostic procedures and differential diagnosis in the group of these diseases focusing on characteristics and treatment of hypereosinophilic syndrome. The treatment has been varied and included steroids, hydroxyurea, interferon-alpha, and in some cases chemotherapy. On the basis of FIP1L1-PDGFRa fusion gene hypereosinophilic syndrome would be classified as a clonal disease and in the FIP1L1-PDGFRa positive cases the tyrosine kinase inhibitor imatinib mesylate (Glivec) would be effective.