Hematopoietic cell transplantation (HCT) transfers a small number
of hematopoietic stem cells (HSC) from a donor to a recipient, where
they are able to differentiate and proliferate to restore a normal
hematopoietic and immune system (see eFig. 133.1).
HCT is performed in patients with life-threatening hematologic disorders
or as a means to restore hematopoietic function following administration
of otherwise lethal doses of chemotherapy or radiation for treatment
of resistant malignancies. HCT also has the potential to cure disorders
resulting from defects in the pluripotent progenitor cells or in
a single hematopoietic lineage.
Development of hematopoietic cells from the pleuripotent
stem cell. Characteristics of the hematopoietic stem cell include
the capacities for differentiation and for self-renewal. BFU, burst
forming unit; CFU, colony forming unit; CFU-GEMM, Colony-forming
unit—granulocyte, erythrocyte, monocyte, macrophage; E,
erythroid; Meg, megakaryocyte; GM, granulocyte/macrophage;
HCT is most commonly used to treat aggressive hematopoietic malignancies
that have not responded to conventional therapy (see eFig. 133.2).
Acute lymphoblastic leukemia is the most common indication for HCT
in children who fail to achieve remission following induction chemotherapy,
or in those that relapse following chemotherapy. In general, 65% to
75% of patients in first remission, 40% to 50% of those
in second remission, and 10% of those with more advanced
disease will survive long term (see Chapter 449).1,2HCT
is not typically performed in first remission unless the leukemia has
features such as the Philadelphia chromosome, which predicts a poor
prognosis with conventional chemotherapy. In patients with acute myeloid
leukemia, HCT is generally indicated at first remission if an HLA–identical
sibling donor is available (see Chapter 450).3 Other
hematologic malignancies, such as chronic myelogenous leukemia,
juvenile chronic myeloid leukemia, myelodysplastic syndromes, and
myeloproliferative syndromes, are considered appropriate candidates
for HCT, and in certain instances, HCT is the only potential modality
Proportion of pediatric patients given hematopoietic
cell transplant according to diagnosis (left panel) or donor cell
source (right panel).
ALL, Acute lymphoblastic leukemia; AML, Acute myelogenous leukemia;
CML, Chronic myelogenous leukemia; MDS, myelodysplastic syndromes;
MRD, HLA-matched related donor; Auto, Autologous; Alternative, Alternative
stem cell donors.
Hematopoietic cell transplantation (HCT) is also used to treat
some pediatric solid tumors. The hematopoietic cells generally come from
the patient, although other donors have been used. The transplant
typically is performed after chemotherapy, and sometimes surgery
or radiation, has reduced the tumor burden sufficiently. Neuroblastoma
is the most common solid tumor for which HCT is used (see Chapter 457). Results of randomized studies have indicated that HCT, when
performed at a point of minimal disease, improves survival.6 Patients
with relapsed Hodgkins or non-Hodgkins lymphoma also may benefit
from HCT, which results in approximately 50% long-term ...