Hematopoietic stem cell transplantation (HSCT) is a procedure which is used to treat chronic conditions such as MS and some forms of cancer. It has been used since the mid-1990s to treat MS and other auto-immune diseases in small but growing numbers of people.
In simple terms, the procedure’s aim is to replace unhealthy blood cells with healthy ones. Bone marrow, found at the centre of some bones, produces stem cells. These stem cells have the ability to become different types of blood cell, each of which perform specific functions that help our bodies stay healthy. For example, they can become red blood cells which help to distribute oxygen around the body, or white blood cells which are instrumental in supporting our body’s fight against infections.
Platelets, also known as thrombocytes, which help our blood to clot therefore preventing bleeding, are another stem cell derivative.
The critical roles that stem cells play in keeping the human body fit and healthy has led to them being used to treat a wide range of disorders (1).
There are many treatments being developed using stem cells which cover a wide range of medical conditions. However, this booklet is specifically about HSCT as a treatment option for MS.
There are different types of HSCT which are used for stem cell transplantation. These are autologous HSCT (aHSCT) and allogeneic HSCT. Autologous means that stem cells are taken from the patient and allogeneic HSCT is when stem cells are taken from a donor. In most instances, MS will be treated using autologous hematopoietic stem cell transplantation (aHSCT).
AHSCT is a procedure that involves harvesting stem cells from the patient’s blood, then wiping out the existing immune system via chemotherapy. The stem cells are then transplanted back to the patient which enables the immune system to rebuild (2).
Since the turn of the century there has been a slowly growing evidence base which underpins HSCT’s high level of effectiveness in treating MS, and other auto-immune conditions. According to the European Group for Blood and Marrow Transplantation (EBMT) registry there were over 1,400 transplants completed throughout Europe alone during 2019 for people with MS. The majority were conducted in the UK, Italy, Sweden, and Poland. HSCT for MS is organised using a multi-disciplinary approach, meaning it will involve input from services such as haematology and MS specialist teams (3).
HSCT is a major focus of international research and new learning is emerging all the time, however existing data is enough to know that it can be used as a treatment for MS. A recent evidence-based review, conducted by members of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in partnership with the EBMT found that approximately 70-80 per cent of people with relapsing remitting MS (RRMS) who had the treatment experienced no evidence of disease activity (NEDA) up to five years post-transplant (3).
The aim of HSCT is to thoroughly suppress the inflammatory activity caused by MS. improvements to existing MS symptoms have been noted and although not for all people, some improvements to existing disability have been reported post-treatment (3).
We will now take a deeper dive into research detailing the efficacy and safety of HSCT as a treatment for MS.
HSCT has historically been seen to present much higher risks than standard MS treatments. That said, these risks have reduced over time, with potential benefits of the treatment becoming more prominent.
In the earlier years of using HSCT to treat MS and auto-immune conditions, there was a relatively high post-transplant mortality risk. More recent studies have found that transplant related mortality rates have fallen over time, though figures do vary.
A retrospective, international study published in 2017 looked at 281 MS patients who were historically treated with HSCT between 1995 and 2006. It found that there was a mortality rate of 2.8 per cent within 100 days of transplant (4). Since then, a 2025 study conducted by the same author found that in their sample of 364 patients with MS who underwent HSCT treatment in the UK, transplant related mortality within the same 100-day period had decreased to 1.4% (5).
Some studies have posted transplant related mortality levels as low as 0.2 per cent, and while there are differences in reported figures, the general trend is that rates are falling worldwide. Indeed, a recent Swedish study involving 231 people with MS who underwent HSCT treatment found there was not a single case of transplant related mortality (6).
Sheffield Teaching Hospitals, one of the most experienced HSCT treatment centres in the UK, advise patients that there is a related mortality rate of one per cent. This reflects the range of possible associated transplant risks, despite no deaths connected to someone with MS being treated with HSCT at the hospital (7).
What we do know for certain is that outcomes for people with MS being treated with HSCT have greatly improved as clinicians across the world gain greater experience and clinical knowledge. Health systems have learned how to improve patient selection, refine transplant techniques, and gained accreditation to help standardise the HSCT process for MS and autoimmune diseases.
Better results for patients treated with HSCT are associated with younger patient age, the patient having RRMS, and with a lower Expanded Disability Status Scale (EDSS) score at the time of treatment.
Sheffield Teaching Hospitals, along with hospitals from around the world, were part of the ‘MIST’ trial. This trial, which took place between 2005 and 2016, included 110 people with RRMS. The study compared outcomes of HSCT to existing ‘best available’ disease modifying therapies (DMT). Its aim was to measure the time it took for participants’ MS to progress or worsen measured by EDSS changes and other neurological criteria (8).
The trial found that the EDSS score of people receiving the transplantation improved from an average of 3.5 to 2.4, whilst for those using DMTs, their EDSS scores declined from an average score of 3.3 to 3.9. At three years post-transplant it was found that six per cent of people receiving HSCT had experienced disability progression, compared to 60 per cent for those in the DMT treatment arm.
More recently a retrospective study covering 20 years of post-HSCT outcomes for people with MS in the UK found that overall progression-free survival (PFS) was just over 80 per cent at two years post treatment, and almost 63 per cent at five years. It was found that people who were more impacted by disability at the time of receiving HSCT had reduced PFS outcomes post-treatment (5).
Compared to most other MS therapies, HSCT treatment is more intensive and involves more risk as it uses high doses of chemotherapy (7).
Chemotherapy has a wide range of possible short and long-term side effects. Short-term effects include hair loss, nausea, sickness, tiredness, rashes, and diarrhoea. In the main, these normally last a few weeks, and hair regrowth should begin within a few months.
Permanent infertility issues can arise in both males and females. Indeed, a recent review of studies conducted over a 20-year period found that just over half of females who received HSCT treatment subsequently became infertile. For males, this figure was just over one-third (9). If fertility is a concern for you speak to your medical support team prior to deciding whether or not to go ahead with HSCT treatment. Consider the options of having your eggs frozen, if you are female, or for males, having sperm frozen prior to treatment.
There is also the possibility of developing secondary autoimmune disease post-transplant. This means that some may be at an increased risk of developing other auto-immune conditions. Studies have shown that the risk of developing a secondary autoimmune condition is just under 10 per cent at five years after HSCT treatment (10).
Graft versus host disease (GvHD) can also occur within a few months of HSCT treatment. This is where transplanted cells attack the patient’s recipient cells with symptoms such as diarrhoea, sickness, shortness of breath and joint pain (11).
It is usually mild and reactive to treatment but can be more serious for some. GvHD is more common in those who have received stem cells from a donor, as occurs in allogenic HSCT, however it can affect some people who receive autologous HSCT treatment. Studies have shown that GvHD incidence in people receiving autologous HSCT is between one and five per cent, compared with approximately 50 per cent for those who have received allogenic HSCT therapy (12).
There are other potential issues to consider as well. Whilst your body is creating healthy blood cells after having your stem cell transplant there will be an increased risk of the following
The clinicians overseeing your treatment will have ways of supporting you if you encounter any problems. Haematology services should explain the whole process and any associated risks.
HSCT is a treatment that is not suitable for everyone with MS and needs to be considered thoroughly. The short-term risks are substantially higher than other forms of MS DMTs, but the possible long-term impact on MS could potentially cease its progression. Whether or not to go ahead with HSCT is a complex decision to make, one that should include the support of those closest to you and a specialist multidisciplinary team. This will include the coordinated expertise of health professionals from various disciplines including neurology, haematology and reproductive medicine (3). They can speak with you about their thoughts of the suitability of HSCT treatment, its potential risks and benefits.
More information
The Anthony Nolan charity provides a wealth of information about stem cell therapy and fertility
www.anthonynolan.org/patients-and-families/preparing-a-stem-cell-transplant/fertility-after-a-stem-cell-transplant
Macmillan Cancer Support offer some useful guidance concerning chemotherapy related hair loss.
www.macmillan.org.uk/cancer-information-and-support/impacts-of-cancer/hair-loss
There is no major surgery involved in the transplantation process. HSCT will involve a lot of preparatory appointments, approximately 30 days as an inpatient in hospital with many months of monitoring post-transplant. During this time there will be certain lifestyle adjustments including reviewing your dietary intake and rehabilitation.
Stage 1
Growth factor and chemotherapy medications are delivered by infusion. These are administered to help your stem cells become mobilised so that they move from bone marrow to the general bloodstream.
Stage 2
When there is enough stem cells present in your bloodstream, which is usually a few days after the mobilisation process, the stem cells are then collected from your blood. This will involve you being connected to a machine that will gather and separate your stem cells and return the blood to your body.
Stage 3
The stem cells are frozen until needed.
Stage 4
A further, more intensive ‘conditioning chemotherapy’ is used to suppress or wipe out your immune system. This chemotherapy can be given at different levels of intensity depending on where you are being treated and which regime the hospital is using.
Stage 5
Your stem cells are then thawed, re-infused and ‘transplanted’ back into your system.
Stage 6
Supported with blood products and antibiotics, the immune system will begin to rebuild. During this time, you are especially vulnerable to infection. You will need to be especially careful of avoiding infection and you will be monitored closely.
Stage 7
You will require follow-ups and monitoring as an outpatient for a few months which will include regular blood tests and appropriate medication. The follow-up appointments should involve both MS specialists and haematologists (13).
The Joint Accreditation Committee of the International Society Cell and Gene Therapy Europe (JACIE) is Europe’s official accreditation body that promotes excellence in the field of HSCT. It is an initiative produced by the European Society for Blood and Marrow Transplantation (EBMT) and International Society of Cell and Gene Therapy (ISCT).
All HSCT procedures completed in the UK will be at JACIE-accredited centres, all of which will work according to the same rigorous standards with each centre being inspected regularly.
Under the NHS, HSCT for the treatment of MS is available at various locations around the UK for people that fall into certain eligibility criteria. The NHS England treatment algorithm for MS offers guidance to neurologists regarding patient eligibility for DMTs including HSCT. It states that HSCT can be offered to patients with relapsing forms of MS as a second or third-line treatment for those who are experiencing disease activity, including relapses, despite taking highly effective disease modifying drugs (14). Disease activity is evidenced via MRI scans which will show if new lesions have appeared within the CNS.
Health Technology Wales updated their latest guidance in July 2020 and found that evidence supports the use of HSCT for people with RRMS that have had continued disease activity despite previous DMT use (15).
The Scottish Health Technologies Group (SHTG) published advice in October 2019 and states that HSCT should be made available via the NHS to people with MS who meet eligibility criteria. This criteria states that people affected by RRMS who have evidence of disease activity and have not responded to high-efficacy DMTs should be offered HSCT treatment (16).
NHS hospitals that offer HSCT treatment will likely follow guidelines provided by the EBMT. They aim to provide general guidance on transplant indications to inform individual patient decisions led by their multidisciplinary team. The EBMT guidelines suggest a range of issues should be considered prior to HSCT treatment being offered to patients. This includes assessing the risk of each patient to ensure the procedure is as safe and successful as possible. Considerations should cover medical co-morbidities, the patient’s general health, and anything which may compromise patient safety and successful outcomes of the treatment (17).
It is important that everyone who is interested in HSCT treatment are aware of the potential risks of the procedure. Risks may differ from one person to another and these need to be clarified by members of the multidisciplinary team before treatment goes ahead. We looked at general risks of HSCT treatment earlier in this booklet.
If you are interested in HSCT and feel that you fulfil the eligibility criteria, it is worth discussing this with your MS team. They can answer any questions you have about the potential risks and benefits of the treatment, if it would be suitable for you and if so, the centres at which you may be treated.
If you have tried to access HSCT treatment under the NHS and have been refused, then there is the possibility of accessing private treatment in the UK. This can be costly and prices can differ greatly between different clinics and hospital sites.
HSCT to treat MS is currently available privately in the UK at specialist centres based in London and Sheffield (7) (18). There will still be eligibility criteria that need to be met which includes recent MRI scans showing evidence of new disease activity, along with comparable recent baseline scans. You will also need to be referred to these centres by your MS neurologist or GP
More information You can view the current list of JACIE accredited centres in the UK, Europe and beyond on the EBMT website.
www.ebmt.org/ebmt
In recent times some people with MS have chosen to access HSCT treatment abroad. This has been due to reasons such as not being deemed eligible for treatment via the NHS, their neurologist would not refer them for private treatment within the UK, or simply because they felt that waiting to fulfil eligibility criteria was not an option. Understandably for some, going outside of the UK for treatment may feel like their only option to access HSCT.
Undergoing treatment abroad may need careful consideration and planning to ensure you get the best care possible. Eligibility criteria may differ from centre to centre, with some willing to treat people with ‘active’ and ‘non-active’ forms of MS. Each centre will have their own eligibility criteria, so anyone interested in going abroad for treatment will need to check these prior to making any further plans.
Earlier in this booklet we explained how the EBMT sets guidelines which hospitals in the UK and Europe follow when administering HSCT. Hospitals outside of Europe offering HSCT may not work with the same regime as the EBMT suggests. However, they may belong to other accredited bodies in their home nations and work to different protocols.
It is therefore important to check that any centres you are interested in are accredited with bodies that ensure adherence to internationally agreed standards of practice, such as JACIE and the Foundation for the Accreditation of Cellular Therapy (FACT) who are a US based organisation that are members of the ISCT.
The EBMT and JACIE published general information for people considering HSCT. It says that although they recommend seeking treatment in your home country, if travelling, it is better if you have the full support of your MS specialist, a transplant specialist, or your GP. (13)
Follow-up monitoring and aftercare medications will be needed once at home, and this will need arranging and facilitating carefully. The EBMT therefore recommend that before arranging treatment abroad, people discuss follow-up care arrangements with their local health services (13).
It is also worth investigating the experience of the clinic and clinicians in question, speaking with people who have been through the process and making sure you have anticipated and planned for as many potential issues as possible. Just because the clinic is not in the UK does not necessarily mean that it will not be able to deliver good quality transplant procedures.
You can visit the current list of FACT Accredited Institutions
The charity Auto Immune and Multiple Sclerosis (AIMS) has been set up to specifically support people with MS and autoimmune diseases with an emphasis on HSCT. They can offer travel grants and peer support.
www.aimscharity.org
Researchers and advocates hope that through larger trials, with higher numbers of participants, evidence can be gathered to underpin the safety and efficacy of HSCT treatment for MS. Star-MS is a trial that is currently ongoing in the UK, testing the safety and efficacy of HSCT for treating highly active MS.
They have participating hospitals in England, Wales, and Scotland. In total there are nineteen hospital sites taking part in the trial, with almost 200 participants. The trial is comparing HSCT treatment against Ocrevus (ocrelizumab), Lemtrada (alemtuzumab), Mavenclad (cladribine) and Ofatumumab (kesimpta), which are the highest efficacy approved DMTs available via the NHS (19). Initial results from the Star-MS trial are expected during 2027.
BEAT-MS is a trial based in the United States which was officially launched in 2019. This randomised trial is designed to compare the efficacy and safety of HSCT against existing high efficacy DMTs, over a six-year period. All participants have active RRMS or SPMS which has been resistant to the best available DMTs (20). It is expected that results from this trial will be published soon after its completion in late 2029.
Be Part of Research provides details of current and historical clinical trials in the UK. This can be used by people who are interested in taking part in a trial or those who wish to find out more about the trials which have taken place.
www.bepartofresearch.nihr.ac.uk
The Clinical Trials website provides information regarding current and historical clinical trials around the world.
www.clinicaltrials.gov
MS-UK asked veterans of the HSCT process to share their thoughts and insights about life after HSCT. The following is a snapshot of their feedback.
AIMS
Autoimmune and multiple sclerosis (AIMS) is a charity that has been set up to support people living across the UK looking to seek HSCT as a treatment for MS and other autoimmune conditions. They offer information, peer support, signposting, grants and more.
MS-UK’s YouTube channel
Scott McCormick recorded a series of exclusive videos all about his journey with HSCT. You can view them all on our YouTube channel.
HSCT for MS
This YouTube channel documents the journey of MSer Chris Wasey during his HSCT treatment in the UK.
There are a variety of Facebook support groups with a wealth of personal insights and experiences. The more popular and active groups are listed below.
Scottish HSCT Network
A not-for-profit organisation offering information and support to people in Scotland considering HSCT as a treatment. They have a Facebook group and are led by people with experience of MS and HSCT.
UK HSCT Facebook group
HSCT Hematopoietic Stem Cell Transplant – MS & Autoimmune Diseases Facebook group
HSCT Veterans Support Group for Autoimmune Diseases
You can view the current list of JACIE accredited centres in the UK, Europe and beyond on the EBMT website.
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