title: Improving the outcome of bone marrow transplantation by using CD52 monoclonal antibodies to prevent graft-versus-host disease and graft rejection.
abstract: Graft-versus-host disease (GVHD) is a major cause of mortality and morbidity after allogeneic bone marrow transplantation, but can be avoided by removing T lymphocytes from the donor bone marrow. However, T-cell depletion increases the risk of graft rejection. This study examined the use of CD52 monoclonal antibodies to eliminate T cells from both donor marrow and recipient to prevent both GVHD and rejection. Seventy patients receiving HLA-identical sibling transplants for acute myelogenous leukemia (AML) in first remission were studied. An IgM (CAMPATH-1M) was used for in vitro depletion of the graft and an IgG (CAMPATH-1G) for in vivo depletion of the recipient before graft infusion. No posttransplant immunosuppression was given. Results were compared with two control groups: (1) 50 patients who received bone marrow depleted with CAMPATH-1M, but no CAMPATH-1G in vivo; and (2) 459 patients reported to the International Bone Marrow Transplant Registry (IBMTR) who received nondepleted grafts and conventional GVHD prophylaxis with cyclosporin A (CyA) and methotrexate (MTX). The incidence of acute GVHD was 4% in the treatment group compared with 35% in the CyA/MTX group (P <.001). Chronic GVHD was also exceptionally low in the treatment group (3% v 36%; P <.001). The problem of graft rejection, which had been frequent in the historic CAMPATH-1M group (31%), was largely overcome in the treatment group (6%). Thus, transplant-related mortality of the treatment group (15% at 5 years) was lower than for the CyA/MTX group (26%; P =.04). There was little difference in the risk of leukemia relapse between the treatment group (30% at 5 years) and the CyA/MTX group (29%). Survival of the treatment group at 6 months was better than the CyA/MTX group (92% v 78%), although at 5 years the difference was not significant (62% v 58%) and neither was the difference in leukemia-free survival (60% v 52%). We conclude that T-cell depletion is a useful strategy to prevent GVHD, provided that measures are taken to ensure engraftment. Using CAMPATH-1G to deplete residual host lymphocytes is a simple and practical method to do this. At least in AML, the beneficial reduction in GVHD can be achieved without an increased risk of relapse.
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, UK. geoff.hale@path.ox.ac.uk
authors.forename: G
authors.initials: G
authors.lastname: Hale
authors.forename: M J
authors.initials: MJ
authors.lastname: Zhang
authors.forename: D
authors.initials: D
authors.lastname: Bunjes
authors.forename: H G
authors.initials: HG
authors.lastname: Prentice
authors.forename: D
authors.initials: D
authors.lastname: Spence
authors.forename: M M
authors.initials: MM
authors.lastname: Horowitz
authors.forename: A J
authors.initials: AJ
authors.lastname: Barrett
authors.forename: H
authors.initials: H
authors.lastname: Waldmann
mesh_terms: D000074323:Alemtuzumab; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D016026:Bone Marrow Transplantation / Q000401:mortality; D016572:Cyclosporine / Q000627:therapeutic use; D018572:Disease-Free Survival; D006084:Graft Rejection / Q000517:prevention & control*; D006086:Graft vs Host Disease / Q000188:drug therapy / Q000517:prevention & control*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015470:Leukemia, Myeloid, Acute / Q000628:therapy*; D008212:Lymphocyte Depletion; D008727:Methotrexate / Q000627:therapeutic use; D015999:Multivariate Analysis; D011379:Prognosis; D013997:Time Factors; D019172:Transplantation Conditioning; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; D007166:Immunosuppressive Agents; D000074323:Alemtuzumab; D016572:Cyclosporine; D008727:Methotrexate