By combining prenatal transplants of blood-forming stem cells with manipulations of blood cells after birth, researchers at The Children's Hospital of Philadelphia achieved immune tolerance in mice, allowing donor cells to multiply without toxic side effects. The studies appear in related articles in the August and September issues of Blood.
The finding could greatly broaden the use of cell and organ transplants for genetic diseases detected before birth, such as leukemia, sickle cell disease, muscular dystrophy, and some kidney and liver disorders.
"Recent developments in genetic knowledge and technology are converging to make it likely that within a decade, nearly all human genetic diseases will be diagnosed before birth," says Alan W. Flake, M.D., director of the Children's Institute for Surgical Science at The Children's Hospital of Philadelphia, and senior author of both articles. "Our research may greatly expand our ability to use prenatal interventions to help the body safely tolerate treatments for genetic diseases."
Dr. Flake's team used a prenatal procedure called in utero hematopoietic stem cell transplantation (IUHSCT). Hematopoietic stem cells develop into red blood cells, white blood cells and a variety of immune cells. The stem cells used in these studies were taken from the bone marrow of adult mice, not from human embryos.
As a disease treatment, prenatal stem cell transplants have faced a major barrier in that they have been unable to achieve high levels of engraftment the number of donor stem cells usually does not grow large enough to overcome the effect of dis
Contact: John Ascenzi
Children's Hospital of Philadelphia