Second Allogeneic Hematopoietic Stem Cell Transplantation After Donor Replacement in Children With Severe Aplastic Anemia.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective measure for the treatment of severe aplastic anemia (SAA). While infection, graft failure, and graft-vs-host disease (GVHD) are the main causes of allo-HSCT failure, a second HSCT is needed to eliminate the dependence of blood transfusion and maintain disease-free survival. We applied low-dose total body irradiation (TBI) + fludarabine (FLU) + cyclophosphamide (CTX) + antilymphocyte globulin (ALG) + busulfan (BU) as a conditioning regimen of second HSCT after a transplantation with an HLA-mismatched donor. As for retransplantation donors, 1 child had an unrelated HLA-matched donor, and 2 children had related HLA-mismatched ones. The latter underwent more serious GVHD with a relatively high cytokine level, and the former had no obvious GVHD after the second HSCT. All 3 patients achieved a desirable effect within 1 month and received satisfactory therapeutic effect during the subsequent follow-up, indicating the convincing effectiveness and safety of this method.