MINIMIZING GRAFT-REJECTION IN ALLOGENEIC T-CELL-DEPLETED BONE-MARROW TRANSPLANTATION

Between October 1991 and May 1994, 42 patients were treated with cyclo phosphamide, thiotepa, and total body irradiation followed by an allog eneic transplantation of marrow depleted of T cells with soybean agglu tinin and E-rosetting. Patients included in this study had acute myelo genous leukemia (13), chronic myelogenous leukemia (12), acute lymphoc ytic leukemia (nine), Hodgkin's disease or non-Hodgkin's lymphoma (fou r), multiple myeloma (three), or myelodysplastic syndrome (one), The m ean age was 34 (range 8 to 51 years), Nineteen patients had a matched sibling donor and 18 received marrow from 6/6 matched unrelated donors while five received transplants from unrelated donors disparate at on e DR locus (5/6 match), Time to granulocyte engraftment (AGC greater t han or equal to 500/mm(3)) occurred at a mean of 16.5 days for related and 11.4 days for unrelated transplant recipients, and was related to the increased use of G-CSF in the unrelated population, There was no correlation with number of mononuclear cells, T cells, or CD34-positiv e cells infused, the rate of engraftment or the incidence of transplan t complications, Multivariate analysis determined that G-CSF administr ation and a diagnosis other than ALL were the only factors associated with a faster rate of engraftment, Patients receiving unrelated donor transplants, those with ALL, or those who had a low T cell number infu sed (less than or equal to 8.0 x 10(3) cells/kg) experienced delayed h ospital discharge, The regimen resulted in excellent rates of engraftm ent (95.2%) with only one failure to engraft and one graft rejection, The incidence of grade III-IV acute graft-versus-host disease was 0% w ith sibling and 26.1% with unrelated donors, There were no cases of ve no-occlusive disease, Fifty percent of patients are alive with a mean follow-up of 26.4 months. We conclude that this regimen is well tolera ted and results in excellent engraftment with a low incidence of sever e graft-versus-host disease and few therapy-related toxicities.