Acute myeloblastic leukaemia: graft-versus-host and graft-versus-leukaemia responses to autologous IL-2 activated lymphocytes in rapid and slow disease.

Thirteen adults with acute myeloblastic leukaemia (AML) in early 2nd complete remission (CR) were treated with recombinant interleukin-2 (IL-2) and autologous IL-2-activated peripheral blood lymphocytes (LAK cells). All 13 developed IL-2-induced in vitro lymphocytoxicity against K562 and Daudi target cells. After seven years' follow-up, there was no overall improved survival compared with a historical control group treated with chemotherapy alone. However 7/13 patients developed T-cel-associated cutaneous graft-versus-host disease (GVHD), and 4/4 of these tested showed in vitro evidence of a T-cell-mediated graft-versus-leukaemia (GVL) effects. These had significantly longer 2nd CRs and survived longer. More lymphocytes were harvested and more LAK cells were reinfused in these seven cases. Since these patients also had longer 1st CRs, their GVL response to IL-2/LAK cells could be a feature of slowly progressive disease.