Successful salvage unrelated umbilical cord blood transplantation with two units after engraftment failure with single unit in severe aplastic anemia

Unexpected unrelated umbilical cord blood stem cell engraft in two patients with severe aplastic anemia that received immunosuppressive treatment: A case report and literature review

Severe aplastic anemia (SAA) is a life-threatening bone marrow disorder. Bone marrow transplantation is the primary therapy for SAA; however, its efficacy is limited by numerous factors, including lack of histocompatible sibling donor, patient age and graft-versus-host-disease (GVHD) following transplantation. Immunosuppressive treatment (IST) is the first procedure developed for patients without a sibling donor. Our previous study reported that patients administered enhanced IST, in addition to a regime of unrelated umbilical cord blood (UCB) transfusion, exhibited higher efficiency and a reduced rate of relapse. Therefore, the present study reported the cases of 2 patients that received enhanced IST plus unrelated UCB transfusion. These patients exhibited complete hematological recovery with an increased rate of mixed chimerism and demonstrated no signs of GVHD or relapse during the 2-year follow-up period. Thus, enhanced immunosuppressive treatment (low-dose cyclophosphamide and antithymocyte globulin) combined with UCB transfusion may be an effective treatment for patients with SAA.

Haploidentical allogeneic haematopoietic stem cell transplantation as salvage therapy for engraftment failure after unrelated and autologous stem cell transplantation: a case report and review of the literature

Engraftment failure is a rare but life-threatening complication of haematopoietic stem cell transplantation (HSCT) and treatment of this condition is often challenging. This case report describes a patient with acute myeloid leukaemia and engraftment failure after unrelated donor allogeneic stem cell transplantation. Rescue treatment with granulocyte-colony stimulating factor and reinfusion of autologous 'back-up' stem cells failed, but transplantation of haploidentical donor stem cells following a fludarabine and antithymocyte globulin (ATG)-based conditioning regimen resulted in haematological reconstitution and long-term disease-free survival. The use of haploidentical donor stem cell transplantation as salvage therapy after engraftment failure in adult patients has not, to the authors' knowledge, been previously reported. Additionally, a review of the relevant literature is presented. This case report and literature review suggest that reinfusion of cryopreserved 'back-up' haematopoietic stem cells is a safe and effective salvage therapy for engraftment failure after allogeneic HSCT. Haploidentical donor stem cell transplantation after a fludarabine and ATG-based conditioning regimen could provide effective second-line therapy in adult patients.