Maintaining a Higher Level of Haemoglobin: Effect on the White Cells After Bone Marrow Transplantation in Children.

The investigators know that children requiring bone marrow transplant need to first go through a myeloablative regimen, which induces a neutropenia. The length of the neutropenia has an incidence on the risk of contracting bacterial and fungal infections that could be lethal. It is then important to find ways to accelerate the neutrophil recovery, so patient survival can be improved. Studies conducted in the '70s and '80s suggested that if the hemoglobin level could be kept at a higher level, then the neutrophil recovery would be accelerated. Other studies also support the hypothesis that if the stem cells do not need to produce red cells because these are being supplied through transfusions, then the stem cells would differentiate into non-erythroid cell lines. As of now, for patients undergoing a bone marrow transplant, it is standard practice to transfuse with red cells based on the condition of the patient or if the hemoglobin level falls below 70 g/L. Hematopoietic growth factors have been used to increase the speed of the neutrophil recovery, but studies conducted so far do not demonstrate that mortality and length of hospitalization have been reduced by the specific use of G-CSF. In more recent studies, these agents have been shown to also have negative effects, such as delayed platelet recovery and impaired immune recovery. In addition, the prophylactic use of G-CSF was also associated with graft-versus-host disease, treatment-related mortality and death. In conclusion, this study will determine if maintaining a higher hemoglobin level has an effect on the neutrophil recovery after allogenic bone marrow transplantation in children.