Hypereosinophilic syndrome with multiple organ dysfunction treated by allogeneic bone marrow transplantation.

A 26-year-old man with hypereosinophilic syndrome who had initial neurologic, cardiac, and pulmonary dysfunction, high eosinophil count, thrombocytopenia, and bone marrow fibrosis had only a transient response to conventional treatment with corticosteroids and hydroxyurea. He therefore received human lymphocyte antigen-identical allogeneic bone marrow transplantation (BMT) after conditioning with cytoxan and fractionated total body irradiation. Hematologic recovery was prompt, with normalization of blood counts and bone marrow. The patient died less than 3 months after transplantation from diffuse cytomegalovirus infection. Potential interest of BMT in patients with resistant hypereosinophilic syndrome and features of poor prognosis is discussed.