Allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation is a potentially curative procedure for a variety of malignant and non-malignant diseases of the bone marrow or the immune system. It consists of administration to the recipient a conditioning regimen including various combinations of chemotherapy, radiotherapy and immunotherapeutic agents which aims to destroy its immune system (to prevent transplant rejection) and, to a varying degree, malignant clone. Conditioning is followed by injection of the graft of hematopoietic stem cells. In this graft, the cells can recognize and destroy residual tumor cells of the recipient (graft effect against leukemia HVL). This reaction explains the interest of the allogeneic stem cell transplantation in hematological malignancies. Meanwhile, the immune system of the graft m⁷y c⁷use deleterious re⁷ctions ⁷g⁷inst recipient's organs that is the GVHD (graft against the host disease). HCT is associated with morbidity and mortality related to the toxicity of conditioning, GVHD and post-transplant immunosuppression. The incidence and severity of these complications depends on both parameters specific to the recipient (age, status of the blood disease) and the terms of the graft (type of packaging, HLA compatibility between the donor and the receiver, ex vivo manipulation of the graft, graft type). The development of new techniques and transplant procedures has improved the survival of transplanted patients and expand transplant indications. The main progress concerns the development of reduced conditioning, peripheral stem cell transplant or cord blood, and improved HLA typing techniques in unrelated transplants.