In October 2018 in Japan, for the first time in the world, a Parkinson’s patient was treated with reprogrammed stem cells. The man in his 50s was implanted at the University of Kyoto with dopamine progenitor cells, previously extracted from the cell material of an anonymous donor.
For this purpose, adult donor cells were reprogrammed into so-called induced pluripotent stem cells (iPS cells) and then developed into progenitors of dopamine neurons. They are meant to replace the dopamine-producing cells in the brain that have died off in the course of the disease. This is expected to alleviate or even revert the typical motor symptoms of the disease, as has been observed before in trials with monkeys. It is the first time that the transplantation of iPS cells is being tested on a human brain.
During the three-hour surgery, neurosurgeon Takayuki Kikuchi and his team implanted 2.4 million dopamine precursors in one hemisphere of the patient’s brain into those areas, which are known for their high dopamine activity. The results have been positive: thus far the patient is well and showing no major adverse reactions. If no further complications occur, Kikuchi and his team will implant another 2.4 million dopamine precursor cells into the same areas of the patient’s other brain hemisphere. Up until the end of 2020, a further six patients will be treated with this method to further test its efficacy.
The results thus far are a spark of hope for Parkinson’s patients worldwide. The results and findings from Kyoto over the coming weeks and months will greatly advance research on the treatment and cure of Parkinson’s Disease.
As a limitation it has to be stated that the implanted cells are created from the cells of a “foreigner”. So, the recipient has to take immune system suppressing medication for a long time to keep his immune system from killing the grafted cells. This medication can have serious side effects.
An advantage of this approach is that the same cell material can be used for different patients, which is cost-efficient. But it cannot be excluded that despite immune system suppression, parts of the implanted cells are rejected and killed. This would lower the overall efficacy of this method.
Therefore, the Förderverein Parkinson-Heilung e.V. prefers the use of autologous cell material for each single patient, even though it may be costlier. Research in this area has shown up to now that it does not cause an immune reaction and has the best possible survival rate of the transplanted cells. Not having to take immune system suppressing medication is another clear advantage from the perspective of the patients.