Studyof Allogeneic Hematopoietic Stem Cell Transplantation From One Haplotype Mismatch Related Donor or From an Unrelated Donor in Elderly Patients

Allogeneic (Allo) hematopoietic stem cell transplantation (HSCT) is a recognized curative procedure for hematological malignancies. It is now well known that this property is related to the graft-versus-tumor (GVT) effect developed from the immunocompetent cells contained in or generating from the donor graft. For years, however, and despite this unique antitumoral activity, Allo-HSCT has been restricted to a limited number of patients due to two major limitations: the toxicity of the procedure and the absence of a donor for every single patients. More recently the stage has dramatically changed with respect to these two restraints. Over the last decade, many studies have established the feasibility of Allo-HSCT in older patients but the availability of MRD is even less frequent in elderlies, likely related to medical contraindication for graft donation or sibling deaths. UD are routinely used but associated with a high incidence of GVHD. As compared to younger populations, unrelated cord-blood HSCT is seldom performed in this population and numbers decrease with age due to the feared risk of supposed increased lethal infectious complications related to the effect of the delayed immune reconstitution in elderlies. Thus the need for alternative donors allowing for a safe and efficient transplantation is still unmet. In consequence, overall, despite the fact that Allo-HSCT feasibility has been established in the oldest patients, all these lacks contribute eventually to maintain a low rate of allo-HSCT performed in a population with the higher incidence of hematologic malignancies that usually present with the poorest prognosis. Thus it is critical developing innovative efficient therapeutic strategies answering this unmet-medical need. In this perspective, Haplo-HSCT could represent a part of the answer in this aged population. It offers the potential advantage to offer a rapid donor determination for virtually every single patient. In addition, our data suggest that