Multiple sclerosis is a chronic autoimmune disease of the central nervous system. It involves the body attacking myelin, which insulates the nerves – which of course results in the devastating damage. As this degenerative disease progresses it causes horrendous disabilities, from muscle weakness and tremors, paralysis, loss of speech, vision problems.... and all in the prime of a person’s life. As yet there is no definite cure. But recent stem cell research has provided new hope to sufferers.
Richard Burt and his colleagues from the Chicago Northwestern University Feinberg School of Medicine used chemicals to destroy the immune systems of 23 patients with early stage MS that had not responded to conventional drugs during a 6 month period. They then injected the stem cells they had previously extracted from each individual’s bone marrow. Seventeen of these patients’ disability rating actually improved by 1 point or more, and not one of the patients’ conditions has deteriorated yet three years after the treatment. Follow the link below to view an interview with one of the test subjects.
http://www.youtube.com/watch?v=Y8SAgUB5hQs
This process works because once transplanted, the bone marrow stem cells differentiate into immune cells. With the patients previous immune system destroyed, these new immune cells are ‘naive’ – that is, they don’t recognise the body’s myelin as foreign and so do not attack the material, effectively halting neuro-degeneration.
This breakthrough relies on our understanding of stem cells and how they function. Stem cells are undifferentiated cells that have the ability to self-renew and specialize into a variety of different types of cells. The extent of this ability to differentiate is determined by the source of the stem cells – the most common of which are embryonic and somatic stem cells. The more primitive embryonic stem cells are of course the most pluripotent, with the ability to become almost any tissue in the body – however one of their major disadvantages lies in the controversial ethical issue of the harvesting of live embryos.
Above: Embryonic stem cells
Somatic stem cells, also known as adult stem cells, have a limited ability to specialise by varying degrees. Different types are found in different tissues, where their role is to maintain and repair that particular tissue. In this case, the bone marrow stem cells that have been extracted and cultured from each individual have been sufficient for the purpose of generating fresh immune cells. This has also eliminated the potentially fatal possibility Graft Versus Host Disease (where the donor transplant attacks the host’s body) as the cells are the patient’s own.
Above: a stem cell from bone marrow
Before the current successful MS trail, Burt and his team attempted the same stem cell treatment on later stage patients to little avail. "If you wait until there's neuro-degeneration, you're trying to close the barn door after the horse has already escaped. What you really want to do is stop the autoimmune attack before it causes nerve-cell damage” says Burt.
Clinical trials for this revolutionary treatment are now underway. In the future it is feasible to imagine that stem cells will hold the key to curing many human diseases, and thankfully for MS sufferers this prospect now appears tantalisingly close to reality.
Resources
http://www.newscientist.com/article/dn16509-multiple-sclerosis-reversed-with-stem-cell-therapy.html
http://www.youtube.com/watch?v=Y8SAgUB5hQs
http://stemcells.nih.gov/
http://www.nhlcyberfamily.org/treatments/sct.htm
http://www.msaustralia.org.au/
http://www.msra.org.au/news/index.php
By Hailey Ward
