01 February 2009
ByAppeared in BioNews 493
A promising new stem cell therapy has reversed the effects of multiple sclerosis (MS) for the first time. In a small clinical trial published in the journal Lancet Neurology, researchers from the Northwestern Freinberg School of Medicine, Chicago, US, treated MS sufferers with their own stem cells, resulting in significant relief of neurological dysfunction in over 80 per cent of those treated and disease stabilisation in the rest.
MS is an autoimmune disease in which the immune system attacks the central nervous system, destroying the myelin sheath - the fatty coating that surrounds nerve cells and is essential for nerve cell signalling. It is a progressive disease with no cure. In the first stage of illness, known as relapsing-remitting MS, the individual experiences intermittent bouts of symptoms such as blurred vision; loss of balance and coordination; weakness or paralysis of limbs; and incontinence. In between relapses a full or partial recovery is made. In the second stage of the disease, which usually develops within 10 to 15 years from original onset, gradual but permanent neurological damage occurs.
In the new study, the researcher isolated haemopoietic stem cells (HSCs) from the bone marrow of 21 MS sufferers and stored them frozen whilst they treated the patients with chemotherapy to destroy all the immune cells, known as lymphocytes, in their body. After the patients had been depleted of these cells, the researchers replenished their immune system by transplanting the stored HSCs back into their bone marrow. The HSCs formed new lymphocytes which did not attack the myelin sheath. Study leader, Professor Richard Burt said: 'we focus on destroying only the immune component of the bone marrow and then regenerate the immune component, which makes the procedure much safer and less toxic then traditional chemotherapy for cancer'.
Patients were selected for the trial if they were in the early relapsing-remitting stage of MS but had not responded to conventional drug treatments which can sometimes help to relieve early symptoms. After receiving stem cell transplantation, the trial patients were monitored for an average of three years and their disability levels were assessed using the Expanded Standard Disability Status Scale. Seventeen of the 21 patients improved by least one point and the remaining four individuals showed disease stabilisation. Unfortunately, in previous studies this treatment has proved ineffective in late-stage MS patients.
Dr Doug Brown, research manager at the MS Society said: 'it's exciting to see that in this trial not only is progression of disability halted, but damage appears to be reversed. Stem cells are showing more and more potential in the treatment of MS and the challenge we now face is proving their effectiveness in trials involving large numbers of people'. These trials are now underway in the US, Canada and Brazil.