Treatment successfully interrupted the occurrence of relapses in patients with an aggressive form of multiple sclerosis and to prevent the emergence of new brain lesions on MRI.
AUTOIMMUNITY. A Canadian team managed to completely stop the occurrence of new relapses in patients with an aggressive form of multiple sclerosis (MS) and to prevent the emergence of new
brain lesions on MRI. Published in the British medical weekly The Lancet, these spectacular results were obtained by using a stem cell transplant made by the patient's own bone marrow. One
speaks in this case of "allogeneic hematopoietic stem cells."
This is initially forcing the cells out of the bone marrow by using drugs, and to select among them those which carry a particular marker on their surface called CD34. The next step is to wipe out the
patient's immune system by administering a cocktail of drugs (intensive chemotherapy and antibodies). Finally, thirdly, the graft is made transfusion own hematopoietic stem cells CD34.
This therapeutic strategy is based on the fact that the MS is a neurodegenerative disease and inflammatory autoimmune origin. In other words, in these patients, the immune system is targeting
myelin which forms a sheath surrounding the axon neurons of the central nervous system. The myelin sheath serves to insulate and protect the long extensions of neurons, as does, for example
plastic for insulation around electrical son.
MS is particularly responsible for motor and sensory deficits, balance disorders, pain, visual and cognitive disorders. Affecting mostly women, MS is characterized by extensive, reflecting
inflammation as well as by an increase in neurological disability associated with the achievement of axons.
A very aggressive strategy for the immune system
The clinical trial conducted by Canadian doctors in three hospitals in Ottawa and Montreal was conducted in patients aged 18 to 50 years, with an aggressive form of multiple sclerosis (MS). All had
previously been successive breakouts early in the disease and early on had a pretty severe disability.All had progressive disease despite continued for more than a year of background treatment with
drugs acting by altering or modulating the immune response (" immunomodulators") or blocking it (" immunosuppressants "). Finally, most had MRI evidence of brain inflammation.
Several clinical trials have already been conducted in patients with MS and receiving allogeneic haematopoietic stem cells but the results, which focused on small numbers followed by addition of
short periods, were mixed so far. Battered printing gap with the data reported today by the Canadian team that she used a more aggressive protocol to put the immune system rest. One patient
died of liver complications and infection two months after the transplant.
Clinical progression stopped in 70% of 24 patients in the trial
Certainly the Canadian study focuses, too, on a cohort of 24 patients so only with an aggressive form of MS. But this is the first trial showing complete suppression of inflammatory activity
associated with the disease over a long period in patients with MS. Indeed, the hematopoietic stem cells took place between October 2001 and December 2009. It appears that 70% of patients
(17 patients) had no progression of their clinical neurological disease after a mean follow up of 6.7 years. In 7 patients, the disease has nonetheless evolved, but moderately. Improved neurological
function was generally observed in approximately 40% of patients after a decline of 7.5 years after transplantation of hematopoietic stem cells, which is a "remarkable" result given their poor
neurological condition before the transplant, notes Prof. January Dörr (Charity hospital, Berlin, Germany) in an editorial associated with the item.
A mortality rate still high
After a follow-up 13 years post- transplant, the authors report that no relapse occurred, nor new brain lesions have appeared on MRI (314 shots total). In addition, the rate of brain atrophy, frequently noted over time in patients with MS, has slowed to the one usually observed in healthy subjects.
It is likely that this therapeutic approach in multiple sclerosis will not change in the near future treatment of this neurological disease, the mortality rate associated with allogeneic hematopoietic stem cells remains too high.This procedure will remain so even lifesaving treatment pending harmonization and optimization of protocols and improved their safety and job security. According to Prof. Dörr January, this type of treatment should be carried out only "in specialized medical centers both in MS and treatment with hematopoietic stem cells."