Bone-Marrow Purging with Monoclonal Antibodies

High-dose treatment followed by infusion of histocompatible allogeneic bone marrow has been shown to be curative in many patients with acute leukemia. Inherent in this treatment modality are a number of problems, however. Most prominent among them: graft versus host disease or, when using T cell-depleted marrow, graft failure. In addition, age restriction, conventionally applied to minimize morbidity and mortality, reduces the application of allogeneic bone marrowtransplantation to, on the average, about one third of those with the disease, and of these only about one in three will have a suitable donor. Autologous bone marrow support may circumvent some of these problems and restrictions and, under certain conditions, be more effective than currently available conventional treatment protocols. In autologous bone marrow transplantation one of the major problems is the danger of reinfusing residual clonogenic leukemia cells. Remission is usually conceived to be a situation where bone marrow function is apparently normal but there is residual disease undetectable by conventional techniques. It is therefore probable that at least a few leukemic cells will be included in the bone marrow autograft from the remission patient. The numbers reinfused will nevertheless be relatively low, and with the currently used therapeutic modalities it would seem that the observed relapses after ABMT are not