Stem cell therapy is a promising and fast evolving treatment for individuals with spinal cord injuries. Clinical trials with humans are already underway. Different types of stem cells have different and varied abilities that can help restore function, and an ideal treatment protocol remains unclear pending further clinical research, according to a new literature review, published in the April issue of the Journal of the American Academy of Orthopedic Surgeons (JAAOS).
“Stem cell treatment is a realistic hope for spinal cord injury patients,” says lead author Gregory D. Schroeder, MD, a spine research and clinical fellow at the Rothman Institute at Thomas Jefferson University in Philadelphia.
The authors evaluated research findings on different types of stem cells:
Mesenchymal stem cells (MSCs) are most commonly harvested from bone marrow and can prevent the activation of inflammatory responses that lead to cell death. Functional recovery using MSCs in spinal cord injury patients has been mixed.
Peripheral nervous system stem cells can secrete nerve growth factor that aids cell growth and can act as replacement cells temporarily. Limited studies are promising, with one showing marked improvement in sensory scores but no improvement in motor function.
Embryonic stem cells are resilient and many animal studies have shown that embryonic stem cells limit inflammatory responses and promote cell growth. Very few human studies have been published about embryonic stem cell treatment for spinal cord injury patients.
Induced pluripotent stem cells (iPSCs) are derived from adult skin cells and are the newest stem cell being investigated for use in treating spinal cord injuries. To date, no clinical studies have been published. Early animal studies indicate these cells offer benefits similar to those of embryonic cells without ethical issues. (Schroeder, 2016)
Stem Cell-Based Therapies
There is currently no treatment available that restores the injury-induced loss of function to a degree that an independent life can be guaranteed for individuals with spinal cords injuries. Exciting research shows that the transplantation of stem cells or progenitors may support spinal cord repair.
Stem cells are characterized by self-renewal and their ability to become any cell in an organism. Promising results have been obtained in experimental models of SCI showing that stem cells can be directed to differentiate into neurons or glia in vitro, which in turn can be used for the replacement of neural cells lost after SCI. Additionally, neuroprotective and axon regeneration-promoting effects have been credited to transplanted stem cells.
There are still some issues related to stem cell transplantation that must be resolved, including ethical concerns.
A Case Study
In March 2016, Kristopher Boesen was in a car accident that paralyzed him from the neck down. After the accident, he had difficulty breathing on his own due to his injuries and was told he may never be able to regain control of his limbs again.
He could undergo the standard surgery given to patients suffering from a spinal cord injury that would stabilize the spine, but it would most likely do little to nothing for his motor and sensory functions. Boesen chose not to do this surgery but rather enroled in a clinical trial being done involving treatment with stem cells. (Team, 2017)
After just two weeks, he was able to regain some minor motion in his arms and hands and after about three months he was able to write his own name with pen and paper and accomplish many other normal daily tasks. He has gone from having complete immobility to being able to function on his own again. (Team, 2017)
Schroeder, G.D., et. all, 2016. The Use of Cell Transplantation in Spinal Cord Injuries. Journal of the American Academy of Orthopaedic Surgeons, 24(4), pp.266–275
Team, C., 2017. First Paralyzed Man Treated With Stem Cells Has Regained Movement. Spinal Cord Injury & Brain Injury Resource Center. Available at: https://www.spinalcord.com/blog/first-paralyzed-man-treated-with-stem-cells-has-regained-movement [Accessed November 12, 2018]