Thousands of hematopoietic stem cell transplants (HSCT) are performed in children and adolescents annually in the United States. HSCT is being used to treat a growing number of indications including malignancies, nonmalignant hematologic diseases, immunologic disorders, inborn errors of metabolism, and autoimmune disorders (Table 134-1). HSCT is not the first line of therapy for many of these diseases, but is reserved for patients for whom first-line therapy is not sufficient or is ineffective. While most pediatric transplants are performed at tertiary care centers, post-transplant patients receive a portion of their care in community hospitals and local oncologists’ offices. It is important for the pediatric hospitalist to have a general understanding of the medical issues facing HSCT patients who may present to their emergency departments or get admitted to inpatient units.
TABLE 134-1Examples of Pediatric Diseases Treated with Stem Cell Transplant ||Download (.pdf) TABLE 134-1 Examples of Pediatric Diseases Treated with Stem Cell Transplant
|High-Risk Hematoloic Malignancies
|Acute myelogenous leukemia
|Acute lymphoblastic leukemia
|Chronic myelogenous leukemia
|Juvenile myelomonocytic leukemia
|Certain brain tumors
|Hodgkin and non-Hodgkin lymphoma
|Bone Marrow Failure Syndromes
|Severe combined immunodeficiency
|Swachmann Diamond syndrome
|Chronic granulomatous disease
|X-linked lymphproliferative disease
|Metabolic and Inherited Disorders
|Sickle cell anemia
|Lysosomal storage diseases
|Lysosomal storage diseases
HSCT is the process of replacing diseased or dysfunctional bone marrow with stem cells capable of restoring normal hematopoietic function. The three main types of HSCT are autologous, allogeneic, and syngeneic. In autologous HSCT, stem cells are collected from the patient and stored until the time of infusion. Autologous transplant has the advantages of being readily available for current and future transplants if needed, eliminating the risk of graft-versus-host disease (GVHD), more rapid immune reconstitution, and lower short-term mortality rates.1 High-dose chemotherapy followed by autologous stem cell infusion (often called rescue) is used to treat children with some high-stage or relapsed solid tumors, and is employed in gene therapy transplants.2
In allogeneic HSCT, stem cells are collected from another person and infused into the patient following conditioning with chemotherapy and/or radiation. A syngeneic HSCT is a transplant using the patient’s identical twin sibling as a donor. The benefits of allogeneic transplants are that there is no risk of residual tumor cells in the graft, the stem cells have not been potentially damaged by prior therapy, and the cells may exhibit a graft-versus-leukemia effect.3 Disadvantages include the risk of GVHD, less flexible timing of donation, the need for immunosuppression following engraftment, slower immune reconstitution with increased risk of infection, and greater overall morbidity and mortality.
Human leukocyte antigen (HLA) typing is performed to determine the suitability of ...