Retransplantation of marrow and hematopoietic stem cells from normal donors

Abstract

Transplantation of marrow or hematopoietic stem cells (HSC) from a normal donor requires high-dose marrow ablative conditioning in order to achieve full and sustained engraftment [1]. Graft failure is an uncommon problem following transplantation of marrow from an HLA identical sibling, but occurs more frequently in recipients of marrow from an HLA incompatible donor [2]. Graft failure can have catastrophic consequences, and prolonged pancytopenia may place the patient at high risk of infection or hemorrhage. Although severe graft failure is often fatal, autologous recovery of hematopoiesis can occur in some patients. The absence of donor cells and presence of host lymphoid cells suggests rejection as the cause of graft failure. Severe graft failure refractory to treatment with hematopoietic growth factors is a primary indication for retransplantation. Retransplantation may also be necessitated by recurrence of hematological malignancy. Additional immune suppression is usually necessary before retransplantation, and patients are usually very sensitive to the toxicity of additional conditioning therapy, especially if the time interval after initial transplantation is short. The feasibility of retransplantation and the optimal method depend on the primary disease and the condition of the patient.