Researchers from Yale and Sapporo Medical University have reported preliminary success repairing spinal cord injuries in patients using intravenous injections of bone marrow derived stem cells (MSCs).
The results are a major step forward in restoring motor functions in patients with non-penetrating spinal cord injuries.
Published in the journal Clinical Neurology and Neurosurgery, the study describes the findings of a phase 2 trial involving the intravenous infusion of MSCs in 13 patients that had experienced non-penetrating spinal cord injuries weeks beforehand.
Most of the injuries were sustained by falls or minor traumas that resulted in injury to the spinal cord. These injuries resulted in partial loss of motor functions and coordination, sensory loss, and bowel and bladder dysfunction in the patients.
“The idea that we may be able to restore function after injury to the brain and spinal cord using the patient’s own stem cells has intrigued us for years,” said Stephen G. Waxman, Professor of Neurology, neuroscience, and pharmacology at Yale, in a statement. “Now we have a hint, in humans, that it may be possible.”
In the trial, the researchers prepared stem cells from the patient's own bone marrow and cultured the cells in the lab according to a set protocol for a couple of weeks. After the cells were cultured, each patient received intravenous injections of their own stem cells. This meant that each patient was in fact their own control, hence why the study had no placebo control group to compare the results to.
The researchers reported that more than half of the patients in the study had significant improvements in their symptoms after the injections, including key motor functions such as the ability to walk or to use their hands. The improvements were also rapid, with positive outcomes reported within days of receiving the stem cell injections.
The results also indicated the approach was safe, as no adverse effects were reported in the patients. A major concern with stem cell therapies is the chance for tumors to grow, as the stem cells could induce changes in cell proliferation, which could result in worsening outcomes. This, however, was not a concern in the current study.
“Similar results with stem cells in patients with stroke increases our confidence that this approach may be clinically useful,” noted Professor of Neurology and neuroscience at Yale, Jeffery D. Kocsis. “This clinical study is the culmination of extensive preclinical laboratory work using MSCs between Yale and Sapporo colleagues over many years.”
Although promising, the study did have some key limitations. Firstly, there was no placebo control group to compare the outcomes to. Also, the study was not blinded, which means observation bias could have impacted the results – especially when outcomes such as motor function are assessed in patients by the same researchers that gave them the stem cell injections.
Nevertheless, it does open up an exciting avenue for spinal cord repair. The researchers stress more studies and trials should be completed first to confirm these current results, which could take years. However, they remain optimistic that this approach might have clinical significance in the future.
