Pediatric allogenic bone marrow transplantation: A comparison between related and unrelated grafts

The potential of allogenic bone marrow transplantation to cure otherwise fatal malignancies has been established. However, there are numerous toxicities associated with the procedure. In this article we compare the outcome of the various subtypes. We analyzed the records of 49 patients who underwent allogenic bone marrow transplantation between 1992 to 2001 at Columbus Children's Hospital. They ranged from ages 8 months to 18 years (Median 7 years). Twenty-six had HLA identical sibling, 2 HLA mismatched siblings, 15 HLA match-unrelated and 6 HLA mismatched-unrelated (of which 2 were umbilical cord) grafts. These transplants were for a variety of disorders. Nineteen for acute lymphoblastic leukemia, 14 acute myelogenous leukemia, 4 chronic: myeloid leukemia, 3 myelodysplastic syndrome, 3 aplastic anemia, and 2 cases each of Wiskott-Aldrich syndrome (WAS), mucopolysaccharidosis (MPS), and hemophagocytic lymphohistiocytosis (HLH). One of the 49 patients failed to engraft. Acute graft vs. host disease occurred in 12(24%) of the patients. Of the 38 patients evaluable for chronic graft vs. host disease, 3 developed limited and one extensive disease. Relapsed or progressive disease was the commonest cause of death. A log rank test of the overall effect of allogenic bone marrow transplantation was statistically significant (log rank = 7.62, p = 0.05). Similarly comparison of the HLA-identical sibling bone marrow transplantation with all other subtypes combined was significant (Log rank = 4.66, p = 0.006). The decision of whether to proceed with allogenic bone marrow transplantation often is difficult and controversial. It is ultimately guided by the potential benefits and risks of such therapy. Our results indicate that of the various subtypes of allogenic bone marrow transplants, HLA identical sibling transplant is comparatively the safest and most tolerable procedure, with the highest (69%) survival rate.