Pediatric Hematopoietic Stem Cell Transplant.

1. Ellen Fraint, MD* 2. Mary Jo Holuba, MSN, CPNP* 3. Lisa Wray, MD† 1. *Division of Pediatric Hematology, Oncology, and Cellular Therapy, Children’s Hospital at Montefiore, Bronx, NY 2. †Division of Oncology, Children’s Hospital of Philadelphia, and Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA Hematopoietic stem cell transplant (HSCT) has emerged during the past 6 decades as an increasingly successful option to cure a variety of malignant and nonmalignant disorders in children. HSCT has been performed in humans since the late 1950s, with significant success first noted in the 1970s. At that time, indications for transplant began to expand beyond malignancies and some bone marrow failure disorders: the scope of pediatric diseases treatable by HSCT now includes, in addition to malignant disorders such as high-risk acute leukemias and solid tumors, a wide range of hereditary conditions, including storage and metabolic disorders, hemoglobinopathies, and immune deficiencies (Table). View this table: Table. Indications for HSCT in Pediatrics Posttransplant survival in pediatric patients has continuously improved over time from a combination of refined approaches to patient selection, conditioning, and improved supportive care. For example, 5-year survival after a matched sibling donor transplant for pediatric acute lymphoblastic leukemia is now 70%, a remarkable achievement over only a few decades of experience. Improvements in HSCT outcomes are not limited to the care of children with malignancies; they are noted across the breadth of indications for the procedure. For example, newborn screening programs now identify babies with X-linked adrenoleukodystrophy or severe combined immunodeficiency, enabling rapid referrals for HSCT before the onset of symptoms. Performing HSCT urgently in such patients has led to durable cures with excellent long-term outcomes before patients develop sequelae of their hereditary diseases. In patients with hematologic malignancy, the indications for transplant have evolved over time, as survival rates with chemotherapy alone have risen and the ability to stratify patients into risk categories has improved with advanced molecular diagnostic tools. Overall survival for pediatric acute lymphoblastic leukemia (ALL), for example, is greater than 90%, and recent clinical trials aim to maintain excellent outcomes while decreasing exposure to chemotherapy and its …