Reduced-Intensity Conditioning (RIC) in Children with Nonmalignant Disorders (NMD) Undergoing Unrelated Donor Umbilical Cord Blood Transplantation (UCBT)

摘要

INTRODUCTION:Children, as opposed to adults, present with a variety of genetic nonmalignant disorders (NMD) that have the potential for significant morbidity and premature mortality. These disorders include, but are not limited to, hemoglobinopathies [1], bone marrow failure syndromes [2], inherited metabolic disorders [3], and primary immunodeficiency disorders [4]. Alloge-neic hematopoietic stem cell transplantation (HSCT) has been shown to be curative for several of these disorders-either by direct replacement of defective bone marrow precursors as in hemoglobinopathies, primary immunodeficiencies, and bone marrow failure syndromes, or indirectly by delivering normal enzymes to the affected tissues such as liver and brain, through the medium of donor cells [5]. However, unlike hema-tologic malignancies, patients with NMD generally do not receive chemotherapy or immunosuppressive therapy before HSCT and are appropriately regarded as chemotherapy naive, thereby implying increased resistance to engraftment compared to patients with hematologic malignancies.