This paper is a review of progress in the field so far and of the possibilities for the future. It describes two different kinds of stem cell treatment: hematopoietic stem cell transplantation (HSCT) and mesenchymal stem cell transplantation (MSCT).
MS is widely regarded as an autoimmune condition as the immune system seems to turn on the body and attack myelin which is the protective layer that surrounds nerves. The aim of stem cell approaches is to correct the faulty immune system and promote remyelination.
The small scale trials conducted so far are very encouraging especially as the risks of HSCT have been reduced in more recent trials. Larger trials are needed to assess the safety further and to determine how much difference stem cell treatment might make in slowing progression or even reversing disability.
The authors conclude that stem cell therapy offers great hope and promise in the long term.
Stem cells are different from all other kinds of cells in the body as they are unspecialised - this means they are not already dedicated to having a specific function in the body. They are able to survive and divide for long periods of time and, under specific conditions, they have the potential to develop into cells with special functions such as the nerve cells in the brain or the muscle cells of the heart.
Stem cells will probably never be used to grow whole organs, but they may be able to repair patches of damage, and this is the reason for researching their use in MS.
This could be achieved by encouraging stem cells already resident in the body to develop into, for example, oligodendrocytes. Alternatively, cells could be transplanted that would go on to differentiate into a therapeutic cell type that could repair damage or replace faulty cells.
How this study was carried out
This paper is a review of progress in the field so far and of the possibilities for the future.
What was found
The authors summarise research into two different kinds of stem cell treatment: hematopoietic stem cell transplantation (HSCT) and the newly emerging therapy of mesenchymal stem cell transplantation (MSCT).
MS is widely regarded as an autoimmune condition as the immune system seems to turn on the body and attack myelin which is the insulating and protective layer that surrounds nerves. The aim of both approaches is to correct the faulty immune system and promote remyelination.
Hematopoietic stem cell transplantation (HSCT)
Hematopoietic stem cells (HSCs) are found in the bone marrow and are able to mature into a range of blood cells including T lymphocytes. They are generated in large numbers throughout life and continually replenish our blood and immune systems.
HSCT is also known as autologous stem cell transplantation (ASCT). The idea behind HSCT is to destroy the faulty T cells in people with MS and then replace them with T cells that don't attack the body so preventing any further damage.
First, drugs are administered to induce the production of more white blood cells in the blood than usual. The person's hematopoietic stem cells are harvested then purified in the laboratory. The stem cells will be kept until reintroduced into the body later in the procedure.
Next, the person undergoes a regime of drugs and/or radiotherapy to destroy all or part of their bone marrow including any faulty cells that may be contributing to MS. The saved stem cells are then reintroduced with the aim of building a healthy immune system.
The first HSCT trial was conducted in 1997 and the procedure has been refined over the years. Early trials involved people with more advanced MS and used a more aggressive regime to destroy the bone marrow. Some people showed an improvement in their MS as judged by their EDSS score but there were significant side effects and complications including several deaths.
More recent trials have used a less aggressive regime on people with a wider range of EDSS scores. This change has arisen because there is an increased understanding that MS is caused by an interplay between genetic and environmental factors. Consequently, it is thought unnecessary to destroy all of a patient's hematopoietic cells; the new aim is to destroy only self-reactive T cells. This has resulted in far fewer medical complications in people taking part in the trials.
The trials reported so far are only phase I or phase II trials. They are quite small and mainly look at the safety of the procedure as well as giving an indication of whether it may help prevent progression of MS. The first phase III trials are now underway.
The reviewers comment that HSCT may be an effective treatment only for early-stage rapidly progressing MS that does not respond to conventional treatment. In particular, the best candidates for HSCT seem to be relatively young patients with recent disease onset, active inflammatory lesions of relatively short duration and rapidly progressive disease, but who still have low EDSS scores and are unresponsive to conventional therapy. For late-stage MS, HSCT is not as effective and often not advisable given the risks.
The complete section on hematopoietic stem cells (HSCs) can be read online including a table of ongoing trials.
Mesenchymal stem cell transplantation (MSCT)
Mesenchymal stem cells (MSCs) are found in the bone marrow or placenta and are able to develop into certain kinds of specialised cells but not all types. They are thought to control certain parts of the immune system, including lymphocytes involved in causing autoimmune disease, and can induce the production of myelin, postpone disease progression and reverse symptoms in animal models of MS.
As with HSCs, there is the possibility of using the person's own stem cells in the treatment so minimising the risk of rejection or attack by the immune system. Using cells derived from another person could cause rejection similar to that seen sometimes after the transplant of a kidney or other organ.
Clinical trials began in 2001 and are encouraging. A phase I/II open-safety clinical trial examined the clinical potential of MSCT and any side effects in 15 patients with MS. Recipients received both intrathecal (via lumbar puncture) and intravenous autologous bone marrow-derived MSCs. Six months after treatment, they showed marked functional improvement with no adverse reactions. Other trials have also been encouraging.
The complete section on mesenchymal stem cell transplantation (MSCT) can be read online including a table of ongoing trials.
Some studies are testing the idea that it might be more effective to use stem cell therapy alongside a disease modifying treatment (DMT) as the two treatments work in different ways. There is more information on combined therapies online.
What does it mean?
The small scale trials conducted so far are encouraging especially as the risks of HSCT have been reduced in more recent trials. Larger trials are needed to assess safety further and to determine how much difference stem cell treatment might make in slowing progression or even reversing disability.
The authors conclude that stem cell therapy is not a cure for MS but it offers great hope and promise. It will be some years before stem cell treatment could be offered to people with MS although there is no guarantee that it will become a clinical reality.
Holloman JP, Ho CC, Hukki A, et al.
The development of hematopoietic and mesenchymal stem cell transplantation as an effective treatment for multiple sclerosis.
Am J Stem Cells. 2013 Jun 30;2(2):95-107.
Read the full text of this paper
More about stem cells
You can read more about stem cells in the A to Z of MS.
Having bone marrow harvested and transplanted is not a trivial procedure. It is sometimes used in treating some cancers including leukemia and lymphoma. A description of the procedure, including the risks is available on the NHS Choices web site.
The MS Trust is part funding a study in Bristol that will use bone marrow derived stem cells in people with primary or secondary progressive MS. In a short video, researcher Claire Rice explains more about the study. This trial has already recruited all the participants required. The results are expected in 2017.
Research by topic areas...
Symptoms and symptom management
Mohammadi K, Rahnama P, Moayed Mohseni S, et al.
Determinants of sexual dysfunction in women with multiple sclerosis.
BMC Neurol. 2013 Jul 12;13(1):83. [Epub ahead of print]
Read the full text of this paper
Wiedemann A, Kaeder M, Greulich W, et al.
Which clinical risk factors determine a pathological urodynamic evaluation in patients with multiple sclerosis? An analysis of 100 prospective cases.
World J Urol. 2013 Feb;31(1):229-33.
Disease modifying treatments
Tsai CP, Lee CT.
Impact of disease-modifying therapies on the survival of patients with multiple sclerosis in Taiwan, 1997-2008.
Clin Drug Investig. 2013 Jul 17. [Epub ahead of print]
O'Connor PW, Lublin FD, Wolinsky JS, et al.
Teriflunomide reduces relapse-related neurological sequelae, hospitalizations and steroid use.
J Neurol. 2013 Jul 14. [Epub ahead of print]
Bar-Or A, Freedman MS, Kremenchutzky M, et al.
Teriflunomide effect on immune response to influenza vaccine in patients with multiple sclerosis.
Neurology. 2013 Jul 12. [Epub ahead of print]
Suljic E, Sinanovic O, Kurtovic-Alajbegovic A, et al.
Betaferon efficiency indicators in the treatment of relapsing remitting form of multiple sclerosis.
Med Arh. 2013;67(3):178-80.
Rivera VM, Jeffery DR, Weinstock-Guttman B, et al.
Results from the 5-year, phase IV RENEW (Registry to Evaluate Novantrone Effects in Worsening Multiple Sclerosis) study.
BMC Neurol. 2013 Jul 11;13(1):80. [Epub ahead of print]
Read the full text of this paper
Costantini A, Nappo A, Pala MI, et al.
High dose thiamine improves fatigue in multiple sclerosis.
BMJ Case Rep. 2013 Jul 16;2013.
Draulans N, Vermeersch K, Degraeuwe B, et al.
Intrathecal baclofen in multiple sclerosis and spinal cord injury: complications and long-term dosage evolution.
Clin Rehabil. 2013 Jul 15. [Epub ahead of print]
Zajicek J, Ball S, Wright D, et al; on behalf of the CUPID investigator group.
Effect of dronabinol on progression in progressive multiple sclerosis (CUPID): a randomised, placebo-controlled trial.
Lancet Neurol. 2013 Jul 12. [Epub ahead of print]
Castillo-Trivino T, Braithwaite D, Bacchetti P, et al.
Rituximab in relapsing and progressive forms of multiple sclerosis: a systematic review.
PLoS One. 2013 Jul 2;8(7)
Read the full text of this paper
Quality of life
Schwartz CE, Quaranto BR, Rapkin BD, et al.
Fluctuations in appraisal over time in the context of stable versus non-stable health.
Qual Life Res. 2013 Jul 13. [Epub ahead of print]
Berrigan LI, Lefevre JA, Rees LM, et al.
Cognition in early relapsing-remitting multiple sclerosis: consequences may be relative to working memory.
J Int Neuropsychol Soc. 2013 Jul 18:1-12. [Epub ahead of print]
Snyder S, Foley FW, Farrell E, et al.
Psychological and physical predictors of illness intrusiveness in patients with multiple sclerosis.
J Neurol Sci. 2013 Jul 10. [Epub ahead of print]
Plow M, Bethoux F, McDaniel C, et al.
Randomized controlled pilot study of customized pamphlets to promote physical activity and symptom self-management in women with multiple sclerosis.
Clin Rehabil. 2013 Jul 17. [Epub ahead of print]
Pregnancy and childbirth
Lu E, Zhao Y, Dahlgren L, et al.
Obstetrical epidural and spinal anesthesia in multiple sclerosis.
J Neurol. 2013 Jul 18. [Epub ahead of print]
Benedict RH, Rodgers JD, Emmert N, et al.
Negative work events and accommodations in employed multiple sclerosis patients.
Mult Scler. 2013 Jul 10. [Epub ahead of print]