Autologous Transplantation in Patients with Acute Myeloid Leukemia in First Remission with IL-2-Cultured Marrow or Peripheral Blood Stem Cells Followed by in vivo IL-2

Abstract

<i>Background</i>: Autologous transplantation using the patient’s marrow or peripheral blood stem cells is still plagued by high relapse rates mostly due to the lack of a graft-versus-leukemia (GVL) effect. We have developed a strategy to combine immunological purging of the autograft and posttransplant immunotherapy. <i>Material and Methods</i>: Bone marrow (BM) and/or peripheral blood progenitor cells (PBPC) were harvested from patients with AML who had poor prognostic features. Leukapheresis after priming with G-CSF was performed immediately after entering first remission and the harvested cells were cultured for 8 days in the presence of interleukin-2 (IL-2), that supports the expansion and activation of cytotoxic cells. The blood cells were then harvested from the culture containers and given to the patient who had received myeloablative chemotherapy during the culture period. Patients were given daily injections of IL-2 for the first week in order to maintain the cytotoxic activity of the transplanted blood cells. <i>Results</i>: Over the last years we have refined this technique and have treated 19 patients. Side effects have been acceptable with most patients developing high temperatures during posttransplant IL-2 treatment. However, all finished the prescribed course. Transplantation of PBPC either alone or together with BM resulted in much faster engraftment than transplantation with BM alone. Disease-free survival in these high-risk patients is encouraging. <i>Conclusion</i>: Culture of BM and/or PBPC in IL-2 for 1 week allows both immuno-logic purging and adoptive immunotherapy to be applied in patients receiving autografts for AML.