Suffering from a spinal cord injury (SCI) is arguably one of the most traumatic experiences a person can go through. First there is the pain, the loss of sensation and the need to adapt to a life of vastly reduced mobility; then there is often a lack of system control that can affect the bladder and bowels. Perhaps worse of all is the fact that doctors are rarely able to offer much hope for improvement. However, the exciting field of regenerative medicine is developing rapidly and spinal injury patients are already benefiting from prolific research into stem cells and their potential for treating SCIs.
About Spinal Cord Injury
Spinal cord injuries can have various causes, but they are commonly the result of trauma from vehicle accidents, falls, sports or violent attacks. SCIs are graded in severity using the American Spinal Injury Association (ASIA) Impairment Scale which ranges from Grade A, the most severe, to Grade E. Grade A SCIs are also referred to as ‘complete’ and the patient will be unable to move any muscles or feel any sensation below the level of injury.
Following a trauma, the protective vertebrae are damaged and the underlying spinal cord can be either severed (transected) or crushed. In either case, the initial damage to tissue is quickly followed by a cascade of biochemical processes, including inflammation (due to the ingress of white blood cells across the compromised blood-brain barrier), cell death – both natural and ‘programmed’ – and demyelination, which act over a period of days and weeks and cause the area of injury to spread up and/or down the spine, increasing the level of impairment. For example, a combination of disrupted blood flow to the area and pressure caused by leaking cells within the spine result in the mass die off of the oxygen-hungry neurons in the gray matter of the cord. Neurons and oligodendrocytes (the cells responsible for sheathing neurons in myelin) are also killed off by the release of glutamate and other neurotransmitters, while a surge of free radicals also wreak havoc with delicate cell membranes. Those myelinated axons that do survive and could potentially regenerate across the injury site are further thwarted by the scar tissue formed by astrocytes.
The result of both primary and secondary tissue damage overwhelms the body’s regenerative processes. Consequently, although modern medical interventions and aggressive rehabilitation programs mean that many SCIs are not as devastating as they would once have been (where death or complete paralysis was the norm), current treatments are still limited mainly to damage limitation rather than recovery or cure.
How Stem Cells Could Revolutionize SCI Treatment
Stem cells are the body’s own regenerative supercells, able to produce a variety of different types of cell while their line remains unchanged. They range from the completely ‘totipotent’ zygote, able to differentiate into any cell found in the human body (including the placenta) to the ‘unipotent’ progenitor cells which can only create a specific type of target cell. Some stem cells (termed ‘multipotent’) are restricted to generating cells from within one of the three germ layers of the body – the ectoderm (which includes skin and nerve cells); mesoderm (e.g. connective tissue, blood and bone cells) or endoderm (which includes the inner surface of the intestines and the lungs).
There are currently numerous ongoing human trials looking at various ways in which stem cells could potentially be used in the treatment of SCIs. Some of the most promising evidence comes from studies involving stem cells from human umbilical cord tissue (HUCT), donated by mothers following normal, healthy births.
There are two major benefits in using HUCT stem cells for treating patients. The umbilical cord is an abundant source of strong and efficient stem cells and they are immune system privileged, meaning that the body does not recognize them as foreign cells and will not reject them. Therefore there is no requirement for Human Leukocyte Antigen (HLA) matching.
Other promising results come from trials involving the patient’s own bone marrow stem cells. Bone marrow is another rich source of high quality stem cells and many SCI patients who have received injections of autologous stem cells have reported an improvement in their ASIA grading, enhanced control of bladder and bowels and a partial recovery of motor control and sexual function.
Although both HUCT and bone marrow produce mesenchymal stem cells (MSCs) (normally dedicated to generating cells of the mesoderm layer), there is evidence that these can migrate and form neural cells through the process of transdifferentiation.
It is thought that stem cells work in a variety of ways to help repair the delicate tissue of the spinal cord. On the one hand, they can replace the neurons and myelinating oligodendrocytes needed to restore the disrupted neural network while, on the other, they help to suppress inflammation and produce substances which can soak up damaging free radicals and toxins.
In addition to the Phase I and Phase II human trials mentioned above, there are numerous ongoing animal trials focused on understanding the regeneration process more fully and on identifying the safest, most effective and most cost-efficient stem cells, growth factors and techniques for the future treatment of SCIs.
A Typical Stem Cell Procedure for SCI Treatment
So what can an SCI patient expect when taking part in a stem cell trial using their body’s own MSCs? No two procedures are exactly alike, but the following is fairly typical:
The first part of the trial will normally focus on evaluation of the injury and the patient’s health, including blood tests, followed by the stem cell harvesting process. This is normally performed under light general anesthetic with MSCs taken from the hip bones, in the case of bone marrow stem cells; or under mild sedation and local anesthesia, in the case of adipose-derived stem cells. Bone marrow stem cells, because of their smaller relative numbers, need to be expanded (grown) by culture. Adipose-derived stem cells, on the other hand, are easier to procure and more plentiful, so the first treatment can be given almost immediately.
Once concentrated, the stem cells need to be screened for quality and numbers; and then the first aliquot of cells can be injected back into the patient, both intravenously and intrathecally (into the fluid surrounding the spinal cord) using multiple injections over a period of weeks, from the expanded cells.
Throughout the treatment period there would be regular follow-ups and active rehabilitation. It is essential for the research team to study the efficacy of the treatment, to monitor the patient’s condition and to determine whether any improvements need to be made to the existing trial protocols.
Where Next for SCI Stem Cell Research?
Despite large numbers of positive patient testimonials and case studies, there are still many unknowns in the field of SCIs and the regenerative potential of stem cells. For example, it is still incredibly difficult to create the precise biochemical conditions necessary to guide stem cells into producing the type of target cell required. Even when these conditions are carefully recreated in a controlled laboratory setting it is a much more complicated matter to achieve the same result in vivo (i.e. inside a living body). Then there is the added task of replicating a successful animal model graft in human patients.
Nevertheless, as the body of knowledge grows, the day when we can finally harness the miraculous power of stem cells comes ever closer and the dreams and fantasies of long-suffering SCI patients can finally be replaced by real hope. Even beyond the acute phase and those who have not been recruited in such programs of study, stem cell deployment can be of benefit, effecting significant improvement in a few individuals.
Please be aware that the Gulf Coast Stem Cell & Regenerative Medicine Center (GCSCRMC) does not currently offer stem cell therapy for the acute phase of SCIs. However, beyond the acute phase and for patients living with certain other neurological disorders, MS stem cells center offers treatment with stem-cell-rich Stromal vascular fraction (SVF), which may be of benefit in restoring varying degrees of function, depending on the condition and severity. To find out more, we invite you to call (886) 855 4823 or to visit GCSCRMC website at http://www.gulfcoaststemcell.com