Stem cells have the potential to help treat many different conditions, including MS. While there are currently no approved stem cell treatments for people with MS, there is a huge amount of research underway to try and understand how these cells could be utilized in new MS therapies.
In a hurry? Watch our series of videos presented by leading stem cell researcher Professor Robin Franklin, from the MS Society Cambridge Centre for Myelin Repair, to get a quick overview of what stem cells are and how they could be beneficial for people with MS.
Most cells in the body, like skin or nerve cells, can only carry out very specific roles and are called specialised cells. Stem cells are different because they possess 2 unique features; the ability to make many copies of themselves (self-renewal), and to produce specialised cells (differentiation).
There are 3 main types of stem cells:
- Embryonic stem cells arise very early in development and have the ability to make all of the specialised cells in the body.
- Adult stem cells are found in parts of the adult body, like the bone marrow, skin and brain. These cells have a more limited ability to produce a narrow set of different, specialised cells. For example, a type of adult stem cell taken from the liver is able to produce the different cells that make up the whole organ.
- Induced pluripotent stem cells (iPSCs) are engineered from fully specialised cells. Researchers have recently discovered a way to induce specialised cells, like skin cells, to behave like embryonic stem cells, with the ability to become any type of cell in the body. This is a complex technique and is the subject of much ongoing research.
Stem cells as treatments for people with MS
There are 2 main ways that researchers believe stem cells could be used as a treatment for MS:
Prevention of nerve cell damage
Some stem cells might be able to help prevent or reduce the damage caused to nerve cells. This is called ‘neuroprotection’ and is an active area of research involving adult stem cells from the bone marrow called mesenchymal stem cells.
Repair of damaged myelin
In MS, the protective myelin layer that surrounds nerve fibres is damaged by the immune system. Specialised stem cells in the brain can generate myelin-producing cells that are involved in myelin repair. Researchers are investigating this process, known as remyelination. Greater understanding of how this process is carried out in the body could help scientists to develop new remyelination treatments.
Myelin loss in people with MS can leave nerve fibres exposed and they can become damaged. This can lead to the disabling symptoms associated with MS because these damaged nerves cannot be repaired or replaced by the body. Researchers hope that eventually stem cells might be useful in helping to replace these lost nerves, however at the moment more research needs to be carried out to explore this possibility.
Stem cells as a research tool
There are many ways that stem cells could benefit people with MS, not only as a potential treatment, but also as a tool to help researchers investigate and develop their research.
Stem cells can mimic many aspects of MS in the laboratory, so researchers can test the potential effectiveness of new drugs more quickly. New stem cell technology now allows researchers to compare differences between people with and without MS which could provide valuable information about the causes of MS. This can help us to understand how MS develops and identify new therapeutic targets.
You may read about stem cell treatment centres which claim to provide ‘cures’ for MS, usually in return for thousands of pounds in payment. These claims are misleading: there are currently no approved stem cell treatments for people with MS.
Currently there is not enough known about how stem cells work to ensure that treatments like stem cell transplant are effective and completely safe. This means it is extremely important that any stem cell treatments are given only in strictly controlled and monitored clinical trials.
It is important to note that undergoing this treatment outside of clinical trials can not only have a high financial cost, but could also have implications for your health: unfortunately, a number of people have died as a direct result of treatment by stem cell transplantation. Seeking unlicensed treatments can also have an emotional cost, as there can be disappointment and frustration if the treatment does not deliver the results that were promised.
This highlights the need for properly regulated clinical trials to ensure treatments like stem cell transplantation are safe and effective before they are made available to people with MS or other conditions.
There have been many clinical trials investigating the use of stem cells as a treatment for people with both relapsing remitting and progressive forms of MS.
Hematopoietic stem cell transplantation (HSCT) for MS
Hematopoietic stem cells (HSCs) are a type of adult stem cell made in the bone marrow, and which have the ability to produce the different cells found in the blood. This includes white blood cells – the immune cells – so researchers believe that HSCs might be able to have an effect on the immune system in people with MS.
You may hear about ‘autologous’ stem cell therapy, and this means the stem cells are originally taken from the person themselves. HSCT involves taking a person’s own HSCs from their bone marrow or blood, and then giving them back.
A potential treatment for people with MS involves wiping-out the white blood cells using very strong drugs (chemotherapy) and then using HSCs to help ‘reset’, or reinstate the immune system so that it stops attacking and damaging myelin.
In 2010, the European Group for Blood and Marrow Transplantation (EGBMT, an organisation focused on reporting and improving HSCT technology) reported on the results of many different studies involving over 340 people with both relapsing remitting and progressive MS who received HSCT treatment during the period 1996 to 2007. This comprehensive review looked at the long term consequences of HSCT and reported that 5 years after treatment, MS had not progressed in 45 per cent of people. However, they also found that 2 per cent of people who underwent this treatment died as a result of transplant-related issues.
In 2011, a report following up on a trial of 35 people with relapsing remitting and progressive MS who were included in the EGBMT study above, stated that 15 years after HSCT, MS had not progressed in 25 per cent of people, and disability had improved in 7 people. The researchers suggested HSCT was not a useful therapy for every form of MS because they found that this treatment was more effective in people with ‘active’ MS (people with new or enlarging lesions in the brain). In addition, 2 people died from transplant-related complications in this study.
In the US, 21 people with relapsing remitting MS were treated with HSCT between 2003 and 2005. Three years after treatment, levels of disability had not gotten worse in people on the trial, and 16 people had not experienced any relapses. The researchers that carried out this trial are now pursuing a larger Phase 3 clinical trial which will also compare HSCT to approved treatments for relapsing remitting MS, like Tysabri and beta interferon. A number of people in this trial experienced issues related to immune suppression, including herpes, diarrhoea and internal bleeding.
In 2014, a trial in the US involving 25 people with relapsing remitting MS reported that 3 years after HSCT, disability had not worsened in 91 per cent of participants while 86 per cent had not experienced a relapse.
Mesenchymal stem cell transplantation for MS
Mesenchymal stem cells (MSCs) are found in many parts of the body and are usually taken from bone marrow, skin and fat tissue. They can produce many different types of cells, including muscle and cartilage, and there is some evidence to suggest that they might help promote remyelination and have a positive effect on the immune system.
A number of pilot, or small-scale, studies have investigated the safety of isolating, growing and re-injecting autologous MSCs. These studies have highlighted a number of minor side-effects, and have revealed some promising early results.
The MESEMS trial is an international, multi-centre trial investigating if autologous MSC treatment is safe and beneficial for people with relapsing remitting or progressive forms of MS. This large scale Phase 2 trial will test if early treatment with MSCs is more effective than later treatment, with the first results expected at the end of 2015.
What stem cell research are we supporting?
Stem cell research has the potential to play an important role in both development of treatments for, and to increase our understanding of, MS. However, there are currently no approved stem cell treatments for people with MS available anywhere in the world. This is largely because not enough is known about their effectiveness and the safety of using these cells.
To address these questions we are funding a range of research projects, some of which are co-funded with the UK Stem Cell Foundation, including a clinical trial of stem cells for people with MS:
- We are supporting research looking at how MSCs behave differently in people with secondary progressive MS compared to people without MS in order to understand more about how MSCs might be beneficial.
- More research is required to ensure that HSCT is a safe treatment for people with MS. We are funding a project which is looking at the long-term consequences of HSCT in people with MS who received this treatment.
- As part of the international MESEMS trial, we are supporting a phase 2 clinical trial at Imperial College London. This will investigate the safety and benefit of MSC transplantation in around 15 people with MS. To find out more, watch the interview below with Dr Paolo Muraro who is leading this research project.
Information on clinical trials of stem cell research
We don’t manage or administer clinical trials ourselves, but the following websites provide information about trials, including where they are taking place, who is eligible to take part, and the expected date for collecting data and results from the trial.
It’s really important to think about and understand exactly what is involved in participating in a clinical trial before taking part, as well as considering the risks and benefits. Read our blog post about clinical trials and what might be involved if you decide to take part.
- www.clinicaltrials.gov provides information on trials happening world-wide
- www.ukctg.nihr.ac.uk contains information on trials happening in the UK
Stem cell therapies in MS – a booklet we produced with other MS charities containing more information about stem cells and their potential use in MS
Eurostemcell – the European Union’s website providing unbiased information about stem cells and the latest research into new therapies for a variety of conditions
Patient handbook on stem cell therapies – a booklet produced by the International Society for Stem Cell Research (ISSCR)
UK Stem Cell Foundation website – information on stem cells and research in the UK