Introduction: Stroke is a leading cause of death and disability worldwide. The disease is caused by reduced blood flow into the brain resulting in the sudden death of neurons. Limited spontaneous recovery might occur after stroke or brain injury, stem cell-based therapies have been used to promote these processes as there are no drugs currently on the market to promote brain recovery or neurogenesis. Adult stem cells (ASCs) have shown the ability of differentiation and regeneration and are well studied in literature. ASCs have also demonstrated safety in clinical application and, therefore, are currently being investigated as a promising alternative intervention for the treatment of stroke.
Methods: Eleven studies have been systematically selected and reviewed to determine if autologous adult stem cells are effective in the treatment of stroke. Collectively, 368 patients were enrolled across the 11 trials, out of which 195 received stem cell transplantation and 173 served as control. Using data collected from the clinical outcomes, a broad comparison and a meta-analysis were conducted by comparing studies that followed a similar study design.
Results: Improvement in patients' clinical outcomes was observed. However, the overall results showed no clinical significance in patients transplanted with stem cells than the control population.
Conclusion: Most of the trials were early phase studies that focused on safety rather than efficacy. Stem cells have demonstrated breakthrough results in the field of regenerative medicine. Therefore, study design could be improved in the future by enrolling a larger patient population and focusing more on localized delivery rather than intravenous transplantation. Trials should also introduce a more standardized method of analyzing and reporting clinical outcomes to achieve a better comparable outcome and possibly recognize the full potential that these cells have to offer.
Keywords: adult stem cells; autologous; clinical application; inflammation; meta-analysis; neurogenesis; stroke; stroke recovery; systematic review.
© 2021 Hassani et al.