Graft-versus-leukemia (GvL) effect
The graft-versus-leukemia effect is not a separate procedure but an immune phenomenon seen after allogeneic transplantation: the donor's white blood cells recognize remaining leukemia cells as foreign and destroy them. According to the NCI, this effect can improve the success of treatment, and it is one of the reasons a donor transplant does more than simply rebuild the marrow after high-dose therapy. The phenomenon has two sides: the same donor immune response, directed at healthy tissues, causes graft-versus-host disease.
How it works
After an allogeneic transplant, the patient's immune system is gradually replaced by cells that developed from the donor's graft. Because donor and recipient differ in tissue antigens, donor immune cells can identify leukemia cells that survived the conditioning treatment as foreign and eliminate them. This immune action works alongside chemotherapy and radiation rather than instead of them, and reduced-intensity ("mini") transplants, which use lower conditioning doses, lean on it to a larger degree.
The effect is difficult to separate from graft-versus-host disease, because both arise from the same donor immune response — described by the NCI as graft-versus-tumor when it targets cancer cells. Transplant teams therefore try to steer treatment — through careful donor matching and drugs that restrain the immune system — so as to limit harm to healthy tissues without losing the anti-leukemia benefit.
Used in
Acute Myeloid Leukaemia (AML)
C92-C94
the immune graft-versus-leukaemia effect underpins the efficacy of allogeneic transplantation