Aplastic Anemia Treated by Isogeneic or Allogeneic Bone Marrow Transplantation

Abstract

Isogeneic or allogeneic bone marrow transplantation was tried for the treatment of three cases with aplastic anemia. Case 1, a 19-year-old woman, was infused twice with 2.8×10⁹ and 4.25×10⁹ bone marrow cells respectively from her healthy identical twin. However, post-transplantation recovery in hematologic values was not observed. Case 2, a 10-year-old boy, also received an isogeneic graft twice from his identical twin. In spite of grafting an adequate dose of marrow cells (3.5×10⁸/kg) and a transient increase in reticulocyte count, a complete hemopoietic recovery was not obtained. Therefore, there is a possibility that stem cell replacement might be ineffective in these cases. Case 3, a 28-year-old woman, was found to be compatible in ABO and HLA-A, B, D. Then, allogeneic marrow grafting was carried out by infusing 13.6×10⁹ cells from one of these HLA-identical and MLC-nonreactive siblings with the use of an isolation room and the sterilizing regimen (“GVN”). Although both engraftment and GVHD were not observed, a febrile episode was treated by antibiotics and granulocyte transfusions, and hemopoiesis recovered to the pretransplantation level after three months. This case suggests that sterilization and intensive supportive therapy may be of primary importance for lifethreatening myelosuppression by high-dose chemotherapy. In addition, major histocompatibility complex and immune mechanism in aplastic anemia were discussed in association with bone marrow transplantation.