This could have major implication for the estimated 5 million people worldwide affected by spinal cord injuries – 1.275 million of them in the United States alone, where the cost of treatment exceeds $40.5 billion each year.
Current treatment options are limited to retaining and retraining mobility; no drug therapies are available, but studies pertaining to stem cell treatments are showing great promise for these as well as other neurodegenerative conditions.
A previous study by the group made national headlines when lab rats whose spinal cords had been partially cut in the region of the animal’s neck in a way that disabled their front right paws were able to regain significant use of their paws after being injected with olfactory stem cells. The investigative team took the cells from the olfactory neurosensory epithelium — the part of the nose that controls the sense of smell — in adult volunteer donors who were already undergoing elective sinus surgery. The removal of the stem cells has no effect on the patients’ ability to smell. Also, the minimally invasive surgery is frequently done on an outpatient basis so the cells are readily available and, as such, are a potentially promising source of therapeutic stem cells.
The researchers isolated the stem cells and increased their numbers in the laboratory by growing them in an enriched solution. The cells were then injected into a group of lab rats. Twelve weeks later, these animals had regained control of their affected paws while a control group that received no cells had not.
This latest study continued that original work, by concentrating on contusions caused by blunt force trauma such as that resulting from an automobile accident or a fall. Spinal cord and head trauma are common among soldiers suffering serious combat injuries, too.
Two independent sets of experiments were conducted, beginning two weeks after the rats had received contusions administered in a computer-controlled surgery. In the first group, 27 out of 41 rats were injected with olfactory stem cells, while the remainder received none. In the second group, 16 rats were treated with olfactory stem cells, 11 received no treatment and 10 received stem cells grown from human skin to see how the olfactory cells compared with another stem cell source.
The results once again showed great promise, with 40 percent of the rats treated with the olfactory-derived stem cells showing significant improvement after just six weeks, compared to 30 percent of those treated with human skin-derived cells and only 9 percent of those receiving no treatment. In addition, the olfactory stem cell-treated rats showing the highest rate of improvement recovered much faster than the other groups.
“This is very exciting on numerous levels,” said Dr. Roisen. “As an autologous cell source — that is, the patient is both the donor and the recipient — olfactory stem cells bypass the time a patient must wait while a suitable donor is found, which can be critical to the outcome of the patient’s treatment. They also eliminate the need for immunosuppressive drugs, which have numerous negative side effects.
“And just as importantly, stem cells taken from the nose of an adult do away with the ethical concerns associated with using embryonic stem cells.”
The researchers are in the final stages of their enabling studies, which are scheduled to be completed by summer; Phase 1 safety studies could begin as soon as early next year.