Immune system reset stops MS
An immune system reboot has halted the progression of multiple sclerosis (MS) in 24 patients, doctors in Canada have reported this week.
Writing in the Lancet medical journal, Ottawa Hospital Research Institute's Harold Atkins and his colleagues recruited 25 patients aged between 18 and 50 who were suffering with severe, progressively-worsening MS symptoms.
Each of the patients received an infusion of stem cells collected from their own bone marrow. These samples had been collected previously by using a chemical marker to sieve the cells selectively from the blood stream.
Before the cells were administered, the patients received powerful ablative chemotherapy designed to destroy their own bone marrow and all of their existing immune cells. This technique, which is also used by haematologists treating patients with certain blood cell cancers, is known as an "autograft".
MS is an autoimmune disease caused by immune cells mounting an inappropriate attack on a brain material called myelin, which supports and insulates nerve fibres. Loss of myelin through immune attack is what produces the symptoms and disability suffered by MS patients.
The Canadian team reasoned that, by taking stem cells from the bone marrow that are capable of rebuilding a new immune system from scratch while wiping out the existing, defective, immune response, patients could "reboot" a new immune response from scratch, this time without the brain-damaging aberrant response that had caused MS.
One of the patients regrettably died owing to complications of the transplant, but of the 24 others, all rebuilt a new immune response within weeks of receiving back their stem cells, and all have remained free of MS relapses in the subsequent three year follow-up period.
Prior to their transplants, these 24 patients were suffering at least one disease flare-up per year. The patients have undergone regular neurological examinations and brain scans and as well as showing no further evidence of MS, more than half of them have also show improvements in their neurological function and lower levels of disability.
The researchers emphasise that their findings need to be interpreted with caution and they acknowledge that they have considered a relatively small number of patients and that there were no untreated "controls" in the study.
The success of the study, on the other hand, the team attribute to their more aggressive ablative regimen and greater stringency in selecting stem cells to ensure that no immune cells remained before the transplant that could mount a fresh attack on the nervous system.
Doing this, they say, meant "led to neurological improvement and long-lasting remission free of ongoing treatment," in a substantial number of individuals.