New research results suggest that stem cells in umbilical cord blood are better at destroying leukemia cells than adult stem cells. Umbilical cord blood is increasingly being used instead of bone marrow transplants because the risk of rejection is lower with the immature cells. However, doctors were concerned that just as the stem cells found in cord blood might be less aggressive to the recipient, then they may also be less aggressive to any residual (post chemotherapy) leukemia cells. But while cord blood stem cells haven’t had the “training” that adult stem cells have had, “it seems they can pitch straight in without practice,” says research team member Paul Veys of Great Ormond Street Hospital for Children in London.
Veys and his colleagues compared the impact of injecting immune cells from adult or cord blood into mice with a form of human blood cancer called B-cell lymphoma. Tumours rapidly disappeared in the mice that received the fetal immune cells, but kept growing in those that got the adult cells.
He speculates that the cells may have special immunological abilities that provide immediate protection to a growing fetus. “The implication is that using cord blood may be a better choice to mop up leukemia,” he says.