Allogeneic peripheral blood stem cell transplantation for hypereosinophilic syndrome with severe cardiac dysfunction.

A 42-year-old male underwent an HLA-matched sibling PBSC transplant for hypereosinophilic syndrome (HES) diagnosed in August 1995. Prior to transplant he experienced progressive cardiac and pulmonary dysfunction with red cell and platelet transfusion dependence despite therapy with hydroxyurea, steroids and interferon. He received busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) as conditioning and standard GVHD prophylaxis with cyclosporin A and methotrexate. At day +336 he was transfusion independent without GVHD. Prompt reduction of the eosinophil count (<500/microl) and rapid improvement of cardiac function were documented, demonstrating the reversibility of organ dysfunction. Allogeneic PBSCT is an effective therapeutic option for patients with HES who fail conventional therapy.