title: Effects on erythropoiesis of alemtuzumab-containing reduced intensity and standard conditioning regimens.
abstract: Haemopoietic cell transplantation (HCT) with reduced-intensity conditioning (RIC) has been associated with delayed disappearance of host anti-A and anti-B isohaemaglutinins and hindrance of donor erythropoiesis in major ABO mismatched transplants. Erythroid recovery, disappearance of recipient type and appearance of donor-type isohaemaglutinins was compared in 84 patients undergoing RIC and 50 patients with standard-conditioning (SCo) HCT. All patients received alemtuzumab as part of their conditioning. The incidence of immune-mediated anaemia and red cell transfusion usage were also compared. Immune factors affecting post-transplant erythroid kinetics showed little variance between different conditioning regimens. Disappearance of recipient isohaemaglutinins and emergence of donor red cells proceeded at similar rates in RIC and SCo transplants; the effects of ABO mismatch were marginal. Pure red cell aplasia, alloimmune haemolysis and autoimmune haemolytic anaemia were not more common in RIC transplants. We believe that alemtuzumab played a critical role in dampening immune reactions of both the host and the donor. Patients in both conditioning groups had similar post-transplant erythroid burst-forming unit (BFU-E) counts; BFU-E chimaerism analysis showed that 90-100% progenitors were of donor origin. However, transfusion requirements were significantly higher in the SCo group, due at least partly to earlier onset of bone marrow hypoplasia.
authors.affiliation: Department of Haematological Medicine, King's College Hospital, London, UK. aleksandar.mijovic@kch.nhs.uk
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Mijovic
authors.forename: Atiyeh
authors.initials: A
authors.lastname: Abdallah
authors.forename: Laurence
authors.initials: L
authors.lastname: Pearce
authors.forename: Khalid
authors.initials: K
authors.lastname: Tobal
authors.forename: Ghulam J
authors.initials: GJ
authors.lastname: Mufti
mesh_terms: D000017:ABO Blood-Group System; D000293:Adolescent; D000328:Adult; D000368:Aged; D000074323:Alemtuzumab; D000704:Analysis of Variance; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002678:Chimera; D017707:Erythrocyte Transfusion; D015672:Erythroid Precursor Cells; D004920:Erythropoiesis / Q000187:drug effects*; D005500:Follow-Up Studies; D006388:Hemagglutinins / Q000032:analysis; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007938:Leukemia / Q000097:blood / Q000628:therapy*; D008875:Middle Aged; D011446:Prospective Studies; D017701:Reticulocyte Count; D013997:Time Factors; D014019:Tissue Donors; D019172:Transplantation Conditioning / Q000379:methods*; D055815:Young Adult
chemical_list: D000017:ABO Blood-Group System; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D000970:Antineoplastic Agents; D006388:Hemagglutinins; D000074323:Alemtuzumab