Donor stem cells allowed the newborn to survive until the Japanese liver transplantation

Japanese doctors conducted the world’s first operation to rescue the liver of the newborn stem cells. The baby suffered from a rare genetic disorder where his blood was accumulated ammonia. He needed a liver transplant, but immediately after birth to carry out a transplant too dangerous. To recover exchange of ammonia in the body of the child, the doctors brought in his bloodstream liver cells derived from embryonic stem cells. For several days the signs of intoxication disappeared, and after the liver is safely replaced with a new one. Details of the procedure can be found in the press release of the Japanese National center of health and development of children.

Embryonic stem cells — the most powerful stem cells, which, however, in medicine almost not used. The fact that they are derived from early human embryos, and therefore, it is impossible to establish their mass production. In addition, their use is rather dangerous: inside the body, they can differentiate into any cell type and form tumor.

Japanese doctors invented a new way to use embryonic stem cells from them to grow hepatocytes (liver cells). The fact that in other countries — e.g. USA — when liver damage patients administered hepatocytes from dead donors. In Japan, these donor cells is not enough. But there are few established lines of embryonic stem cells that biologists once received from the “donor” embryos and continue to cultivate in the laboratory.

Recently, such hepatocytes from stem cells implanted in the first patient. It was a newborn child, who on the second day of life showed signs of liver pathology: hypertension and convulsions caused by the increased concentration of ammonia in the blood. It turned out that the baby carrier of a mutation in one of the enzymes of urea cycle: in the liver of toxic ammonia is turned into harmless urea. In such a situation to save a child, only a liver transplant, but her newborn is dangerous, and usually doctors wait until it grows to six pounds.

The child was able to survive a few months with a defective liver, on the sixth day of life to Japanese doctors injected him with 190 million hepatocytes obtained from the culture of embryonic stem cells. They are introduced directly into the portal vein of the liver — so there is less chance that the hepatocytes will move to some other authority. The procedure was successful, no side effects, according to doctors, does not arise. In 9 days the baby was transferred from intensive care to a regular ward, and after two months was discharged. All this time the concentration of ammonia in his blood remained within normal limits even after his food had more protein (the main source of nitrogen and thus ammonia in the body). At the age of five months the child was finally transplanted piece of liver from her father, and this operation is also successful.

This clinical trial demonstrates another example of the use of stem cells — not as the ultimate drug, and as a “bridge” that allows the patient to survive until a cure. Such use relieves several problems. First, the donor cells can die in the body of a patient or to induce an immune response — but in this case, they initially had to spend in the child’s body no more than a few months. Second, other cells can settle in other organs of the body. However, the authors note that the case of liver transplants in this sense is very revealing: during the operation, your own kid’s liver is removed entirely, and this time, you can check what is happening with the ammonia levels in the blood. If it does not grow — means that the donor cells have not spread through the body and remains within the liver and then was removed along with it.

Despite the fact that Japan is considered one of the leaders in the field of regenerative medicine, for the last time it was twice overtaken by the American group the year before transplanted derived stem cells into the brain of a patient with Parkinson’s disease and Chinese doctors six months earlier the Japanese used a similar technique for combating heart disease. But the Japanese are still first in the field of treatment of the cornea — since they raised her from stem cells and implanted in the patient, none of their superiority have not challenged.

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