Spinal cord regeneration trial in paraplegics
July 2003
A year after it first began, a world-first clinical trial into spinal cord regeneration surgery in paraplegics is continuing in Queensland.
This human trial, involving 8 volunteer patients, aims to determine the safety of a pioneering procedure and the potential benefits to those who have suffered a recent spinal injury.
In June 2002, cells harvested from the nose of a volunteer patient with paraplegia were cultured in a laboratory and were transplanted into the patient’s spinal cord in an 8-hour surgical procedure.
 |
| Setting up the special syringe assembly |
The Queensland Spinal Cord Regeneration Project is a collaboration between Princess Alexandra Hospital (PAH) clinicians and Griffith University scientists, and is supported by a $200,000 PAH Foundation grant.
Scientists Dr Francois Feron and Professor Alan Mackay-Sim, from the Griffith University School of Biomolecular and Biomedical Science, have pioneered a method of harvesting and cultivating particular nerve cells — olfactory ensheathing cells, a type of glial cell — from inside the nose.
 |
| Filling the special syringes with cells taken from the patient |
What are olfactory ensheathing glial cells?
The brain has 2 types of cells — neurons and glial cells or glia.
A neuron is the microscopic structural unit of the nervous system, and consists of a nerve cell and its processes. There are thousands of different neurons, each specific for their job. There are fewer types of glia. Neurons cannot reproduce: when they are destroyed, they are not replaced. In contrast, glial cells can divide and multiply.
Olfactory ensheathing cells (OECs) are a class of glia. Unlike other cells in the nervous system, these unique glial cells are continually regenerated throughout life by the olfactory mucosa, the nasal tissue responsible for the sense of smell.
The olfactory nerve ensheathing cells help nerves grow from the nose to the brain and are the only glial cells that can exist both within and outside the central nervous system.
The Griffith scientists are recognised as the first in the world to focus on the nose, rather than the brain, as a source of the glia for transplantation in spinal cord injury.
Are glial cells stem cells?
No. Olfactory ensheathing cells are differentiated cells: they are of a specific type with specific functions.
Stem cells are undifferentiated cells which have the potential to differentiate into many different cell types. Stem cells are present in embryos and are also recognised to be in many adult tissues including bone marrow and brain. These adult stem cells can give rise to many cell types.
Princess Alexandra Hospital Spinal Injuries Unit Director Dr Tim Geraghty said the glial cells used in the trial would be cultured from cells harvested from each of the volunteer patients.
‘During the intricate surgery, the patient’s spinal cord is implanted with his/her own cells, thereby eliminating the risk of cell rejection and the need for anti-rejection medication,’ he said.
 |
| Implanting the cells in the patient |
How are the olfactory ensheathing cells obtained?
Small pieces of tissue are removed from the olfactory organ in the back of the nose. This nasal tissue is treated with enzymes and incubated until a single cell suspension remains. Further treatment results in a purified population of ensheathing cells, which are then cultured for about 6 weeks to increase their number.
Dr Geraghty said the aim of the Phase 1 trial was to assess potential risks and determine the benefits to the patients, who have been carefully selected for the trial and have undergone extensive preparation, including physical, psychological, and neurological assessments.
He said: ‘The volunteer patients (test and control groups) will take part in the trial and their progress will be closely monitored by PAH’s medical, surgical, and allied health teams for up to 3 years.’
What are the expected outcomes?
In a clinical trial, a ‘control’ group provides a comparative tool for the patients who undergo the treatment.
In this Phase 1 trial, some assessors and clinicians will monitor the patients and controls throughout the trial. They will not know which patients have undergone the procedure.
If the surgical group showed any changes which were also noted in the control group, it could mean these are part of the natural course of events, rather than being related to the transplantation procedure.
However, changes occurring only in the patients who undergo the surgery may be a direct result of the cell implantation.
Any changes, both subjective (observed by the patient) and objective (detected through the regular clinical assessments) will be recorded. Any change in sensation, motor function, or control over bodily functions would be a positive outcome.
The next phases of research will depend on the results of this Phase 1 trial, which will take 3 years to complete.
Last Reviewed: 15 July 2003
Sponsored links
