Profile of the procedure:
- Dopamine-producing neurons are extracted from aborted foetuses and transplanted into the region of the striatum in the mid brain of a Parkinson's patient.
- It is very difficult to selectively extract the right cells from the tiny structures of a foetal brain, and thery are also likely to be contaminated with other cell material.
- Since the transplanted tissue originates from a foreign organism, rejection by the immune system must be suppressed in the recipient (immune system suppression).
- The procedure has been tested on a very small scale since 1995.
- The results so far are two-fold: a number of subjects are experiencing significant and sustained improvements, i.e. substantial improvement in motor skills so that previously necessary medication could be discontinued completely (see here). Other subjects experience severe dyskinesia (involuntary and uncontrollable movements).
Politis et al. have found in studies that the dyskinesia is triggered by contamination of the transplanted cell material with serotonin-producing cells.
- The brains of the living as well as of the subjects who died a natural death were intensively examined. It was found that the transplanted cells survive and form coonections with the surrounding regions. In addition, no uncontrolled cell growth or even tumour formation was observed.
- The method is ethically extremely questionable because of the use of aborted fetuses and cannot be broadly used.
Interpretation of results:
- Cell replacement therapies can bring about significant and lasting improvements in Parkinson's disease patients if the right cell material is used.
- Methods that can produce pure dopamine-producing neurons from stem cells are therefore very promising.
Here are some links to studies on the transplantation of fetal stem cells in Parkinson's patients:
and here the European initiative: