Bone marrow transplantation for children with acute leukemia and Down syndrome.

Four children with acute leukemia and Down syndrome received high-dose cyclophosphamide therapy and total body irradiation in preparation for bone marrow transplantation. Skin and mucous membrane toxicity was pronounced. Furthermore, three children died during the immediate posttransplantation period of infectious and hemorrhagic pulmonary complications. One patient had hematologic recovery and is surviving disease-free 1 year following transplantation. These preliminary observations are in agreement with previous data suggesting that children with Down syndrome are at higher risk for toxicity, pneumonitis, and, possibly, death following administration of intensive therapy for leukemia in comparison with children without Down syndrome. Improvements in the management of these children in the future will depend upon a better understanding of the biologic and pathophysiologic aspects of Down syndrome and additional clinical experience.