Benefits of Cord Blood
The umbilical cord is a lifeline, a vital link allowing essential nutrients to pass from mother to fetus. Its starring role is critically important, but usually all too brief. Once the baby is born, the cord is medical waste. Like Rodney Dangerfield, it gets no respect.
Current research has changed all that. Lately, the umbilical cord is getting a great deal of respect. The blood in it contains stem cells, which are normally found in bone marrow. Stem cells manufacture and maintain the body's blood supply by regenerating and differentiating into all the other types of blood cells.
Research into the potential uses of cord blood suggests some intriguing therapeutic possibilities. In one study performed by Nicholas M. Ponzio, PhD, professor of pathology and laboratory medicine at UMDNJ - New Jersey Medical School (NJMS), and Pranela Rameshwar, PhD, assistant professor of medicine in the school's division of hematology, mice were given lethal doses of radiation, then injected with human cord blood. "The majority survived after only one injection, and many were still alive a year later," says Ponzio.
Of great interest was the fact that two weeks after the injection, the mice were tested for the presence of human cells, and none were found. "It appeared that the grafting was only temporary, helping the mice to survive the immediate effects of the radiation but, more importantly, stimulating their own stem cells to produce more blood cells," says Ponzio. "It's possible that as the stem cells of the mice repopulated their immune system, the human cells were recognized as foreign and were subsequently destroyed."
The results suggest a possible role of cord blood to protect against high-dose chemotherapy. For example, a patient with breast cancer could be given high doses of therapeutic agents, which typically would shut down the body's blood-building mechanism. The patient would then be transfused with cord blood, stimulating repopulation of all the blood cells by the body's own stem cells.
Bone marrow transplantation is an accepted therapy for treating diseases that damage or shut down the body's blood-producing mechanism, including malignancies, anemia, and immune deficiencies.
The blood-building qualities of stem cells are the rationale behind the procedure. However, there are many problems associated with it. The success of a marrow graft is dependent on stringent selection criteria to identify a suitable donor. In addition, marrow donation requires general anesthesia and is costly.
If there are mismatches between donor and recipient one complication can be a failure of the transplanted marrow cells to engraft. Such mismatches can also provoke a graft-vs.-host reaction, where the transplanted marrow cells mount a potentially life-threatening immune response against the recipient.
Current research focuses on transplanting stem cells from cord blood, rather than bone marrow, into human recipients. The procedure was first performed in 1970 by Norman Ende, MD, professor of laboratory medicine and pathology at NJMS, and his brother, Milton Ende, MD, of Petersburg, VA, on a young man with acute lymphoblastic leukemia.
An account of the procedure was published in the March, 1972 issue of The Virginia Medical Monthly. However, the report did not receive much attention, and the Endes' milestone is often overlooked. It wasn't until the late 1980s that other published reports of cord blood transplantation attracted the interest of the scientific community.
Hundreds of cord blood transplants have since been performed in the US and around the world. Cord blood has many advantages over bone marrow in transplantation. The harvesting and grafting processes are simple. Because of the immaturity of the cells in cord blood, it appears less likely to be rejected, and less likely to cause severe graft-vs.-host rejections. It can also be stored, so a supply would be immediately available.