After a baby is born and the umbilical cord is cut, some blood remains in the blood vessels of the placenta and the portion of the umbilical cord that remains attached to it. After birth, the baby no longer needs this extra blood. This blood is called placental blood or umbilical cord blood: "cord blood" for short.
Cord blood contains all the normal elements of blood - red blood cells, white blood cells, platelets and plasma. But it is also rich in hematopoietic (blood-forming) stem cells, similar to those found in bone marrow. This is why cord blood can be used for transplantation as an alternative to bone marrow.
Cord blood is being used increasingly on an experimental basis as a source of stem cells, as an alternative to bone marrow. Most cord blood transplants have been performed in patients with blood and immune system diseases. Cord Blood transplants have also been performed for patients with genetic or metabolic diseases. More than 80 different diseases have been treated to date with unrelated cord blood transplants.
Umbilical cord blood contains haematopoietic (blood) stem cells. These cells are able to make the different types of cell in the blood - red blood cells, white blood cells and platelets. Haematopoietic stem cells, purified from bone marrow or blood, have long been used in stem cell treatments for leukaemia, blood and bone marrow disorders, cancer (when chemotherapy is used) and immune deficiencies.
Since 1989, umbilical cord blood has been used successfully to treat children with leukaemia, anaemias and other blood diseases. Researchers are now looking at ways of increasing the number of haematopoietic stem cells that can be obtained from cord blood, so that they can be used to treat adults routinely too.
Beyond these blood-related disorders, the therapeutic potential of umbilical cord blood stem cells is unclear. No therapies for non-blood-related diseases have yet been developed using HSCs from either cord blood or adult bone marrow. There have been several reports suggesting that umbilical cord blood contains other types of stem cells that are able to produce cells from other tissues, such as nerve cells. Some other reports claim that umbilical cord blood contains embryonic stem cell-like cells. However, these findings are highly controversial among scientists and are not widely accepted.
Scientists are investigating the possibility that stem cells in cord blood may be able to replace cells of other tissues such as nerve or heart cells. Whether cord blood can be used to treat other kinds of diseases will be learned from this research.
No comments:
Post a Comment