TransplantationNatural killer cell alloreactivity in allogeneic hematopoietic transplantationRuggeri, Loredana; Mancusi, Antonella; Burchielli, Emanuela; Aversa, Franco; Martelli, Massimo F; Velardi, Andrea Author Information Hematology and Clinical Immunology, Department of Clinical and Experimental Medicine, University of Perugia, Perugia, Italy Correspondence to Loredana Ruggeri, MD, PhD, Hematology and Clinical Immunology, Department of Clinical and Experimental Medicine, University of Perugia, Policlinico Monteluce, Via Brunamonti 51, 06122 Perugia, Italy Tel: +39 075 578 3151; fax: +39 075 578 3154; e-mail: [email protected] Current Opinion in Oncology: March 2007 - Volume 19 - Issue 2 - p 142-147 doi: 10.1097/CCO.0b013e3280148a1a Buy Metrics Abstract Purpose of review This review will focus on the translation of natural killer cell recognition of missing self into the clinical practice of allogeneic hematopoietic transplantation and discuss how it has opened innovative perspectives in the cure of leukemia. Allogeneic hematopoietic stem cell transplantation from a human leukocyte antigen-matched sibling can cure leukemia but 75% of patients do not have a matched donor, one alternative source of stem cells includes full haplotype mismatched family members. As haploidentical transplantation must be extensively T cell depleted to prevent lethal graft-versus-host disease, it cannot rely on donor T cells for the graft-versus-leukemia effect. Mismatched transplantation, however, triggers alloreactivity mediated by natural killer cells which is based upon ‘missing self recognition’. Recent studies Recent studies using preclinical murine models of haploidentical transplantation demonstrated that conditioning with alloreactive natural killer cells ablates the recipient immune system and leukemia cells. In the clinical setting of mismatched hematopoietic stem cell transplantation, donor versus recipient natural killer cell alloreactivity has been associated with better outcome, particularly in patients with acute myeloid leukemia who are transplanted in remission. Summary Given the benefits of natural killer cell alloreactivity, it is expected that it will encourage greater use of haploidentical transplants for the large numbers of leukemia patients without matched donors. © 2007 Lippincott Williams & Wilkins, Inc.