Graft-vs-leukemia following bone marrow transplantation: a model of immunotherapy in man.

Considerable data in animals suggest an antileukemia reaction associated with transplantation of allogeneic bone marrow cells. In some instances, this graft-vs-leukemia (GVL) reaction may be distinct from graft-vs-host-disease (GVHD). Data in humans also support the concept of a GVL effect associated with bone marrow transplantation. These observations include an increased risk of leukemia relapse in identical twin transplants and in recipients of T-cell depleted allogeneic transplants, and a decreased risk of leukemia relapse in individuals who develop acute or chronic GVHD. Although indirect, these findings are among the most convincing evidence that the immune system plays a role against cancer in man. It may be possible to exploit this effect in other settings and with other cancers.