Spinal cord injuries are one of the pathologies that present the greatest medical issues in regenrative medicine. Thus, their possible treatment with stem cells has meant—and means—one of the major challenges for regenerative and reparatory medicine.
Nevertheless, progress in this medical field has been slow and even frustrating, although there seems to be a glimmer of hope. In fact, in mid-January this year, California company Asterias Biotherapeutics announced the promising results of the first 12 months of a clinical trial in which embryonic stem cells were converted into oligodendrocytes (cells of the nervous system that support the neurons and can stimulate their growth). They showed that when these cells were injected into the precise site of patients with a spinal cord injury, 21 of the 22 patients treated showed improved movement.
However, these results are still too premature to consider launching campaigns straight away, because it is not yet clear whether the improvement obtained is due to the injected stem cells or some other reason. In any case, the California company has requested the corresponding permission to initiate a duly programmed phase 2 trial.
Regenerative medicine premature treament of cord injures
Meanwhile, in Japan, a more worrying proposal is emerging. It seems that investigators in the Faculty of Medicine at the University of Sapporo have taken a step forward in the treatment of spinal cord injuries with respect to all treatments that have been carried out so far, including the one from Asterias, and have received authorization to go ahead. Their proposal is to treat these injuries with mesenchymal stem cells. In the opinion of several experts, however, there are scientific reasons to be skeptical, because there are well-founded doubts that these cells can be transformed into neurons, as the Japanese team suggests. Until now, they have only been evaluated in a group of 13 patients, with no control group and without their findings having been published in a quality-assured scientific journal (https://www.nature.com/articles/d41586-019-00178-x).
From our point of view, we do not believe it is ethically justified to start experiments in human patients without the necessary safety guarantees that these practices warrant. Furthermore, to these must be added the ethical difficulties entailed in the use of embryonic stem cells. The use of another type of stem cells must be considered, such as reprogrammed adult cells or iPS cells.
Photo: The Mirror