Successful engraftment after autologous transplantation of 10-day cultured bone marrow activated by interleukin 2 in patients with acute lymphoblastic leukemia.

Disease recurrence remains the major problem in autologous bone marrow transplantation (BMT) for hematologic malignancies. To improve the therapeutic efficiency of autologous BMT, we investigated the use of autologous marrow activated in vitro with interleukin 2 (IL-2) to generate killer cells for in vivo purging. A feasibility trial was initiated in 5 patients with poor prognosis acute lymphoblastic leukemia, who were transplanted, after marrow ablative therapy, with autologous marrow cultured for 10 days with 10(3) units of IL-2/ml. A highly significant increase in NK activity and an induction of LAK activity were observed after incubation. Patients received 0.64 to 1.56 X 10(8) cultured BM cells/kg and 1.87 to 44.8 x 10(4) CFU-GM/kg. Four patients engrafted and achieved granulocyte counts > 0.5 x 10(9)/l on days 35, 24, 36 and 22 after transplant. Three of these patients showed platelet recovery to > 50 x10(9)/l on days 25, 42 and 40 after transplant. One patient remained thrombocytopenic until relapse. One patient died on day 12 after transplant. This study demonstrates that cultured BM activated with IL-2 can be used successfully for hematological rescue in the clinical setting.