Here are the basics: In the first step of the therapy, physicians take some of the bone marrow stem cells from your body and keep them alive. Then they use chemotherapy to, essentially, wipe out your immune system. After that, they put the bone marrow stem cells back into your body. The new immune system cells produced (by the stem cells) are "naive" and do not see the myelin as an invader, or something to be attacked. Therefore, they no longer attack the myelin and the body (apparently) can then get to work healing any early-stage multiple sclerosis damage.
This study was done in 23 patients, all with early stage relapsing-remitting (RRMS) multiple sclerosis (they have tried this before in people with later stage disease and it was not successful). After one procedure, these folks were followed for three years. 17 of them improved by at least one point on the disability scale and none of them got any worse (in terms of disability). There is a larger trial now underway to learn more about the risks and benefits of this treatment (especially the risks and at what stage of multiple sclerosis is the treatment most beneficial).
For clarification, this uses a procedure called autologous non-myeloablative haemopoietic stem cell transplantation. What that means is that it uses a person's own (adult) stem cells and that the chemotherapy doesn't fully destroy the bone marrow.
As the first approach that is really a treatment, meaning it is healing, and not just slowing progression, this is very exciting. Just to reiterate an earlier point, it is unclear how many people with multiple sclerosis will eventually benefit from this, as it seems to be best in early stage, relapsing-remitting multiple sclerosis. I don't know exactly what "early stage RRMS" means in this context. Does this include people who have lived with RRMS for a long time without too much disability or people who have RRMS that were diagnosed recently, but have had several harsh relapses since diagnosis? Let's all keep an eye on this one...
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