Hematopoietic
colony-stimulating factors have been introduced into clinical practice as additional supportive measures to reduce infectious complications associated with congenital or acquired
neutropenia. Over the past decade, we have begun to appreciate the subtler aspects of the proper use of
G-CSF and
GM-CSF, identifying appropriate indications and
contraindications. In the course of evaluating the corpus of studies, a set of formal recommendations have been propagated for the judicious use of these expensive
growth factors. To prevent serious
infection, the use of
G-CSF or
GM-CSF is recommended in a subset of pediatric
cancer patients shortly after having received
chemotherapy or a form of a marrow transplant. Children with highly intensive
chemotherapy (e.g., children with high risk ALL or NHL) seem to benefit from hematopoietic
growth factors whereas this is still unclear for children undergoing
therapy for solid
tumors. An exciting development is the use of
G-CSF and
GM-CSF to mobilize peripheral-blood progenitor cells for autologous or
allogeneic transplantation. In pediatric patients with
hematological diseases, there are only few data on the use of hematopoietic
growth factors in children with
myelodysplastic syndrome. Experts recommend the early administration of
G-CSF in children with very severe
aplastic anemia. The use of
G-CSF is also recommended in children with
severe chronic neutropenia, but these patients have to be monitored regularly for
cytogenetic abnormalities. No larger study has shown a clinical benefit of hematopoietic
growth factor in preterm or term infants. Future studies in pediatric patients are clearly warranted to address several issues. Prospective clinical trials are still needed to define specific treatment groups who can benefit from
growth factor support. In this regard, efforts must be directed at better defining the endpoints and in particular assigning value to reduction in treatment of possible infectious complications, such as days in hospital,
antibiotic usage and costs. In addition, randomized studies are required to evaluate the proper dosage and
duration of therapy, which most likely will vary between groups of patients. In addition, combinations of different
growth factors have to be tested, particularly if ex vivo expansion and the storage of hematopoietic stem cells are to be utilized in a wider spectrum of patients.