According to experts at the 22nd Meeting of the European Neurological Society (Prague, Czech Republic, 9–12 June) current research findings give reason to hope that different types of stem cells could open up new prospects in therapy for severe neurological diseases such as stroke, Parkinson’s or multiple sclerosis. But given the many unresolved issues, neurologists warn about dangerous promises of cures from unscrupulous providers.
“There are a number of highly promising research findings today, which could pave the way to completely new types of stem cell therapies for severe neurological diseases,” Gianvito Martino, San Raffaele Hospital, Milan, said at the 22nd Meeting of the European Neurological Society (ENS). “But we need more time to clarify the many unresolved issues on safety and benefits. At the moment, there is one central message for neurological patients: These therapies are still in an experimental stage. We must urgently warn affected patients not to spend large sums of money to undergo treatments against Parkinson’s, multiple sclerosis or stroke that have not yet been adequately tested.”
Martino went on to say that specialised practitioners in countries inside and outside Europe are enticing severely ill people with false hopes of cures even though the therapies are not yet approved and central safety issues are still not clarified, such as the possibility that stem cell implantation might cause cancer or infections. The market is lucrative. Experts estimate that several billion US dollars are spent every year worldwide for stem cell treatments.
“Despite all the advances, we are still not yet at the point in neurology where the use of stem cells is part of everyday clinical routines. Lawmakers are called upon to protect sick people from stem cell tourism and unscrupulous providers. If patients undergo treatment, they should make sure to do so as part of serious clinical studies approved by the respective bodies.” A number of such studies were just presented at the ENS Congress.
Stroke: Neural stem cells improve sensorimotor functions
According to British researchers, patients in the Pilot Investigation of Stem Cells in Stroke (PISCES) trial are being treated for the first time with a new type of procedure. It involves implantation of neural stem cells in the area of the stroke to trigger the regeneration of damaged nerve cells. There will be an intensive follow-up on patients for ten years.
Neural stem cells are cells that can renew themselves through cell division and differentiate into various types of cells. In animal studies, cells manufactured in a special genetic engineering process by a research team from Glasgow have proved effective. Rats that had suffered a stroke and impaired sensorimotor functions as a result showed substantial improvement after several weeks.
Parkinson’s: Fibroblasts for the brain
Researchers have not yet reached the point of application on human beings for the treatment of Parkinson’s disease. But a team of experts from Milan were able to report in Prague on advances in this area, too. The goal of stem cell therapy in patients with Parkinson’s is to re-trigger the impaired production of dopamine in the brain by implanting neuronal cells.
Italian researchers have now developed a method of circumventing the ethically controversial use of embryonic stem cells to produce neuronal cells. Through the addition of three special proteins, researchers succeeded in converting cells from connective tissue (fibroblasts) into dopaminergic neuronal (iDAN) cells, i.e. into the type of dopamine-producing cells that are lacking in the brains of patients with Parkinson’s. In a next step, researchers will have to determine how best to transplant these cells into the corresponding areas of the brain.
Multiple sclerosis: Double the effect
Martino reported at the ENS Congress that several current studies on humans are already underway for multiple sclerosis. “Cell-based therapies are considered a highly promising way to induce the regeneration of myelin sheaths on nerve fibres damaged when multiple sclerosis occurs. Stem and progenitor cells of neural and mesenchymal origin have proved suitable tools in this context.” According to the expert, current studies show that the way they function is more diverse than originally thought: “We have observed that in patients with MS, this form of stem cell not only replaces destroyed cells but also has an additional effect by releasing neuroprotective molecules.”