The use of stem cells in the regeneration of tissues offers new perspectives and gives hope to the world. Stem cells may regenerate the neurons in Parkinson disease, the cardiac cells destroyed by myocardial infarction or the pancreatic cells that are responsible with the production of insulin.
A new perspective on the use of stem cells appeared: blood transfusions. Andrew Pollack wrote in his article published in The New York Times about the advantages and disadvantages of the replication of erythrocytes in blood transfusions.
Definitively a Great Achievement
The supply of blood is never enough and the lack of it may be filled up with blood made from stem cells. Besides, this will eliminate the risk of using infected blood. Another advantage is the possibility of producing and stocking blood from the O group of the universal donors. Anyway, it is easier to create a certain blood group than a DNA code sequence. The risk of rejection is undoubtedly smaller than in the case of other types of tissue.
However, there are other reasons that animate the interest for the new project. In the case of other types of tissue, after the replication of the cells, there is a problem with the right functioning in the host body. But it is not the case of the blood cells because they are much easier to integrate in the system than a neuron.
The theory is good but the practice puts some serious questions.
The erythrocytes obtained from embryo’s stem cells are more alike with the incipient red blood cells than with the mature ones. They are big and often they have a nucleus, which may affect the blood circulation; and even the formula of the hemoglobin molecule (which transports the oxygen) is slightly different.
How well will these cells work in the human body is not yet known. The erythrocytes produced by now in the lab proved that they can carry the same quantity of oxygen as the adult cells. They have not yet been tested on animals or humans. “The truth is in vivo.” says dr. Thalia Papayannopoulou, teacher at Washington University. She added that artificial cells might not live in the human body as those from donors, because of the differences in membranes.
Another problem is the necessary amount of cells. If in the case of other types of cells a small amount is more than enough, in the case of blood transfusions, the biggest amount obtained so far is only the tenth part of the necessary amount for a single unit of blood transfusion.
Other erythrocytes may be multiplied in the lab: those from bone marrow or from the umbilical cord. But these cannot multiply for ever, so the amount is limited from the start.
The costs are another issue of the experiment. “People donate for free and this is hard to get in different circumstances“, says Dr. Nick Seay, from Cellular Dynamics. “And after processing the donated blood, hospitals have to pay 200 $ for one unit of blood transfusion.”
But “if we take into consideration the costs of producing these cells from stem cells, one unit of blood transfusion may cost thousands of dollars”, says dr. Michael P. Busch, the manager of the Blood Systems, a non-profit research institute.
Research goes on.