BONE-MARROW TRANSPLANTATION IN CHILDREN W ITH SEVERE ACQUIRED APLASTIC-ANEMIA - WHAT CONDITIONING IS OPTIMAL - EXPERIENCE OF PEDIATRIC-HEMATOLOGY-RESEARCH-INSTITUTE

Allogeneic bone marrow transplantation is a treatment of choice for yo ung patients with acquired aplastic anemia. Graft rejection is the mai n problem in this context. We report on seven pediatric patients with severe aplastic anemia grafted in our Institute in 1994-1996. There we re 2 boys and 5 girls aged 5.5-14 years. The mean interval between dia gnosis and transplant was 7 mo (2.5-17). All the patients-were given m ultiple transfusions prior to the transplantation (12-40 transfusions of unfiltered blood products). Conditioning regimen was ATG+Cy 200 mg/ kg in 1 patient, busulfan 8 mg/kg+Cy 200 mg/kg in 5 patients and busul fan 8 mg/kg+ATG+Cy 200 mg/kg in 1 patient, One patient died prematurel y (day+4), 6 patients were evaluable for engraftment. Three patients s uccessfully engrafted, in the rest three primary graft failures were r egistered. In these 3 patients attempt of early second transplant usin g G-CSF or GM-CSF mobilized peripheral stem cells after conditioning w ith ATG was undertaken and; again no engraftment was seen. In 1 patien t (primarily conditioned with ATG+Cy) spontaneous autologous reconstit ution occurred 6 mo after the transplantation. Overall 4/7 patients su rvived 24-36 mo after transplantation. Using Bu 8 mg/kg does not seem to be appropriate for the purpose of improving engraftment rate in hea vily pretransfused patients with AA.