Adoptive immunotherapy with donor mononuclear cell infusions to treat relapse of acute leukemia or myelodysplasia after allogeneic bone marrow transplantation.

Relapse remains a significant problem after allogeneic bone marrow transplantation (BMT). For patients with relapsed chronic myelogenous leukemia (CML), infusions of donor mononuclear cells (MNC) provide a potent graft-versus-leukemia (GVL) reaction inducing complete remissions in the majority of patients. Little is known about the efficacy of donor MNC infusions for patients who relapse with other diseases. We have studied the GVL effects of donor MNC in eight patients with relapsed acute leukemia or myelodysplasia (MDS). One patient with relapsed MDS achieved complete remission and another patient had a transient response. Five of six non-responders died of progressive leukemia and one non-responder died of complications during second BMT. Three patients developed grade I-II acute GVHD responsive to immunosuppression. These data, and review of the literature, suggest that GVL induction with donor MNC infusions is less effective for patients with relapsed acute leukemia than for patients with relapsed CML; too few patients with relapsed MDS have been treated to draw definite conclusions. However, some patients respond, and given the high mortality associated with alternative procedures such as second BMT, donor MNC infusions are a reasonable approach for relapsed acute leukemia and MDS after allogeneic BMT.