Japanese researchers have made progress in the treatment of spinal cord injuries, offering hope to the approximately 20 million people worldwide affected by paralysis. On March 21, scientists from Keio University in Tokyo announced the results of a clinical study, as reported by the Philippine Star. The study found that stem cell treatment improved motor function in two out of four patients who were paralyzed due to spinal cord injuries.
This clinical study is the first of its kind on humans. Keio University researchers used induced pluripotent stem cells (iPS cells) created by stimulating mature, specialized cells back into a juvenile state. These iPS cells can be prompted to mature into different kinds of cells by reverting adult cells to an embryonic state. The team focused on individuals who were injured 14 to 28 days before the operation.
The treatment involved injecting approximately two million iPS-derived neural stem cells into the injury site of each of the four male patients to help regenerate the injured spinal cord. Each man received the stem cell injections two to four weeks after the onset of his paralysis. The number of cells implanted was determined after safety experiments in animals.
Over a year of observation, no serious side effects were observed in any of the four cases after one year of follow-up, according to Keio University. Professor Matthias Endres, director of the Clinic for Neurology at Charité in Berlin, noted the outcome. "Improvements shortly after a spinal cord injury can occur naturally," said Endres, according to the Süddeutsche Zeitung. However, he emphasized the importance of the findings given the challenges in treating such injuries.
Before the treatment, all four subjects had an injury grade of A, the most severe on the American Spinal Injury Association scale, indicating no feeling and no movement below the level of their spinal cord injury. Following the stem cell therapy, one patient's condition improved to grade D, meaning they can move muscles against gravity and perform functional movements. This patient, an elderly man who suffered an injury in an accident, can now stand without support and is undergoing rehabilitation to regain the ability to walk.
"This person is now training to walk. It is a spectacular recovery," explained Hideyuki Okano, the head of the trial and a physiology specialist, as reported by the Süddeutsche Zeitung. Another patient improved to grade C, able to move some arm and leg muscles but cannot stand. Two other participants did not show improvements and remained at grade A after the injection of iPS cells.
The study was supervised by a medical team led by Professor Masaya Nakamura, an orthopedic surgery specialist, and Professor Hideyuki Okano. The researchers believe that their treatment caused the improvements observed in the patients. Japanese neurophysiologists have restored mobility to people with paralysis caused by spinal cord injuries.
Despite the optimism, German experts are cautious in their reactions. Stem cell researcher Daniel Besser, managing director of the German Stem Cell Network, said, "It seems to be a first success, but it needs to be observed further," according to the Süddeutsche Zeitung. He added, "Since the work has only been presented at a press conference and not in a scientific journal, I am very cautious with an assessment."
Neuroscientist James St John from Griffith University also commented on the findings. "That is a wonderfully positive result. It is very exciting for the field," he stated, as reported by the Süddeutsche Zeitung.
There are concerns that iPS cells may multiply uncontrollably in the body and form cancerous tumors. However, no serious side effects were observed during the year-long observation period. The recipients also received immunosuppressive drugs for six months following the operation to prevent their bodies from attacking the implanted cells.
The mechanism by which the reprogrammed stem cells contribute to healing is still unclear. It is assumed that the iPS cells produce biochemical substances to support regeneration. "The cells may also form an insulating layer around nerve cell extensions or establish connections to other cells," Professor Endres explained. There have been successes with iPS cells in other medical areas, such as treating specific eye diseases and diabetes.
Healing a spinal cord injury is one of the greatest challenges in medicine. True nerve cell regeneration has not been achieved so far. "The spinal cord is the most sensitive and least regenerating tissue in the nervous system," Endres said. "Every advance in this field understandably generates great attention."
The next step will be to start larger trials to determine if stem cells can truly repair the damage, according to Italian newspaper Leggo. These trials will investigate which types of injuries respond best to the therapy and assess whether the improvements observed are the result of natural healing, which can sometimes occur. Future research must also answer how many cells survive after the operation, as previous tests have shown that most cells disperse or die within a few days.
K Pharma, a Japanese biotechnology startup, plans to request permission to launch larger-scale clinical trials. This medical achievement is expected to lead to advancements in the treatment of spinal cord injuries, offering a beacon of hope for those affected.
Professor Hideyuki Okano added that the team hopes to move to a clinical trial that represents a step toward providing treatment to patients. Details about the patients remain confidential, and the study's results have not yet been submitted for publication review.
The article was written with the assistance of a news analysis system.