title: Clinical Studies in Hematologic Microtransplantation.
abstract: The anti-tumor effects of allogeneic hematopoietic stem cell transplantation depend upon engraftment of donor cells followed by a graft-versus-tumor (GVT) effect. However, pre-clinical and clinical studies have established that under certain circumstances, anti-tumor responses can occur despite the absence of high levels of durable donor cell engraftment. Tumor response with little or no donor engraftment has been termed "microtransplantation." It has been hard to define conditions leading to tumor responses without donor cell persistence in humans because the degree of engraftment depends very heavily upon many patient-specific factors, including immune status and degree of prior therapy. Likewise, it is unknown to what degree donor chimerism in the blood or tissue is required for an anti-tumor effect under conditions of microtransplantation. In this review, we summarize some key studies supporting the concept of microtransplantation and emphasize the importance of recent large studies of microtransplantation in patients with acute myelogenous leukemia (AML). These AML studies provide the first evidence of the efficacy of microtransplantation as a therapeutic strategy and lay the foundation for additional pre-clinical studies and clinical trials that will refine the understanding of the mechanisms involved and guide its further development as a treatment modality.
authors.affiliation: Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ, 08901, USA.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: David
authors.affiliation: Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ, 08901, USA.
authors.forename: Dennis
authors.initials: D
authors.lastname: Cooper
authors.affiliation: Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ, 08901, USA. strairrk@cinj.rutgers.edu.
authors.forename: Roger
authors.initials: R
authors.lastname: Strair
mesh_terms: D000818:Animals; D018572:Disease-Free Survival; D006086:Graft vs Host Disease / Q000209:etiology; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D019337:Hematologic Neoplasms / Q000628:therapy*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000401:mortality / Q000628:therapy*; D033581:Stem Cell Transplantation / Q000009:adverse effects; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism; D019172:Transplantation Conditioning; D014184:Transplantation, Homologous
chemical_list: D016179:Granulocyte Colony-Stimulating Factor
keywords: Acute myelogenous leukemia; Graft-versus-tumor; Microtransplantation; Stem cell transplantation