Resetting the Immune System with Stem Cells to Fight Multiple Sclerosis
Richard Mollard, MBA, PhD*

Multiple Sclerosis (MS) is a disease that affects signalling within the nervous system. It occurs when the body’s immune system attacks the insulation surrounding its own nerve fibres, reducing the efficiency of signalling between the brain and muscle. As a result, a patient with MS will experience many problems, including: impaired coordination of movement, sight and speech.

The cause of MS is not well understood, but evidence suggests that in some cases a viral attack may alter the body’s immune system so that it recognizes the insulation surrounding nerve fibres as foreign. The immune system will then launch a defensive destruction of the insulation. How severe the disease will be is unpredictable. Some patients suffer milder periodic attacks that eventually result in long-term impairment, while other suffer a severe progressive form with sustained attacks that lead to a consistent decline in bodily function.

Currently there is no cure for MS. A combination of chemotherapy to destroy the immune cells that attack the insulation, and hematopoietic stem cell transplantation to replace the defective immune system has been used to treat patients with the severe progressive form of MS. In some cases this treatment has been associated with a stabilization of the disease. The problem is that in these patients, because the insulation surrounding the nervous tissue is more severely affected, nerve cells die as a secondary consequence and are very difficult to replace. Furthermore, chemotherapy itself can have a very detrimental effect upon the patient’s health.

In a study recently described in the journal Lancet Neurology, Burt and colleagues (1) collected and retransplanted the patient’s own hematopoietic stem cells in patients with the milder form of MS and in the absence of severe chemotherapeutic regimes. The idea was to selectively destroy only the immune cells that were attacking the insulation and reintroduce immune cells that did not recognise the body’s insulation as being foreign. Patients with this milder form were selected because of the lesser chance of secondary nerve damage.

Although this study was not double-blinded or randomised, meaning that the patients and researchers knew that cells were being injected and could therefore be biased by “expecting” or “wanting” to see improvement, the data collected were promising. Patients were assessed up to four years following treatment and not one showed a deterioration in condition. Most patients, significantly, experienced a reversal and sustained improvement in sensory and walking tests. As Burt and colleagues point out, results from double-blinded and randomised trials are now needed to provide further strength to claims that this type of stem cell treatment will offer real benefit to patients suffering MS.

Notes:
1. Burt, R. K., Loh, Y., Cohen, B., Stefoski, D., Balabanov, R., Katsamakis, G., Oyama, Y., Russell, E. J., Stern, J., Muraro, P., et al. (2009). Autologous non-myeloablative haemopoietic stem cell transplantation in relapsing-remitting multiple sclerosis: a phase I/II study. Lancet Neurol 8, 244-253.

*Author Affiliation
Richard Mollard, MBA, PhD
Head: Stem Cells, Respiratory Development and Tissue Engineering
The Department of Biochemistry and Molecular Biology
Monash University
Clayton 3800
Australia

Posted May 20, 2009