Cord Blood Stem Cells
In 1978 scientists discovered that the blood found in the umbilical cord and placenta following a baby’s birth was a rich source of haematopoietic cells and stem cells. Tissue previously regarded as medical waste has become an increasingly stored resource for parents and families both through private and public cord blood banking. The treatments using cord blood are so far fairly limited, with leukaemia, and other blood disorders the major applications. However, there are potentially hundreds of therapeutic applications for cord blood stem cells with researchers investigating their use for numerous degenerative illnesses with no other known cure.
Those awaiting a bone marrow transplant for conditions such as leukaemia are already benefiting from umbilical cord blood stem cells. The time-consuming process of finding a matching donor is happily becoming shorter due to reciprocal agreements between countries such as the US and UK to provide access to umbilical cord blood stem cells. There is less need to have an exact match when using cord blood, in contrast to a bone marrow donor, as the umbilical cord blood cells provoke less of an immune response and thereby lowering the risks of graft-versus-host disease in patients. A bone marrow transplant is also an invasive procedure which can be painful and result in complications for the donor; acquiring cord blood stem cells involves little, if any risk to the donor, although there are concerns over prematurely clamping the umbilical cord.
Multiplying Cord Blood Stem Cells
The placenta itself contains around ten times as many stem cells as the cord blood but this wealth of stem cells usually return to the neonate if the umbilical cord is not clamped immediately after birth. The quantity of stem cells in cord blood was, for many years, insufficient to treat an adult patient needing haematopoietic cells but new methods have been devised to increase the amount of stem cells resulting from the umbilical cord blood. In 2005, Peter Zandstra from the University of Toronto developed such a technique thereby enabling the use of cultured cord blood stem cells to treat adult patients (Raymer, 2006).
In most cases the umbilical cord contains around five tablespoons (30-100ml) of blood with a high ratio of blood- and immune-forming cells in comparison to most other tissues. The stem cells in umbilical cord blood are very similar to those in bone marrow and its uses so far are essentially the same as for bone marrow aspirate itself. Cells within the cord blood include haematopoietic, mesenchymal, and endothelial stem cells although there is hope that these cells may be able to be manipulated in such a fashion as to turn them back into embryonic pluripotent stem cells capable of differentiating into any tissue type. However, the weight of evidence so far suggests that this is unlikely.
Key Dates in Stem Cell Research
The umbilical cord in a full term neonate is around fifty centimeters long and is formed from the same zygote as the foetus, meaning that it is extremely rich in stem cells. This richness was discovered in 1978 when scientists realised that the cord blood contains undifferentiated stem cells of the type CD43-positive and CD38-negative. In 1988 the first cord blood transplant was conducted.
Continue Reading –> Cord Blood Banking
