Sickle cell disorder (SCD) and stem cell transplant

Introduction

For people with sickle cell disorder, a stem cell transplant may now give hope of a cure.

You might have lots of questions if you’ve been told a stem cell transplant may now be a treatment option for you. There’s plenty to think about and consider. We want to help you answer those questions and support you in making the best decisions for your health and future.

Your medical team should know your unique situation best. But we hope this information can guide you through what can be tricky process.

What is sickle cell disorder (SCD)?

Sickle cell disorder is a group of inherited blood disorders that affect the red blood cells in your body. In the UK, it mostly affects people from African and Caribbean backgrounds. It can be diagnosed soon after you are born or even earlier, during pregnancy. Find out more about sickle cell disorder from the NHS.

People with sickle cell disorder have red blood cells shaped like a crescent moon or a ‘sickle’, instead of being round like normal cells. These oddly-shaped cells can clump together and block blood vessels, which makes it hard for blood to flow properly through them and prevents oxygen from reaching different parts of the body. This can cause various health complications and acute pain episodes (often called sickle cell crisis).

For many people, this pain can be severe. It can affect their day-to-day life and result in many stays in hospital. People with severe sickle cell disorder can also be at risk of serious complications. These can result in death.

There are treatments for sickle cell disorder, but not all people respond well to them.

Can I have a stem cell transplant if I have sickle cell disorder?

Yes, you might be able to have a stem cell transplant to cure your sickle cell disorder. You can find out more about what a stem cell transplant involves in our Understanding stem cell transplants section. This treatment has been an option on the NHS for adults in the UK since 2020.

You are likely to be offered a stem cell transplant only if the benefits outweigh the risks. It is likely you will have severe sickle cell disorder which:

• cannot be controlled with pain management or other treatments
• means you spend a lot of time in hospital to treat your acute pain episodes
• affects your quality of life so you cannot go to work, take part in education, socialise, or carry out normal day-to-day activities
• causes or puts you at high risk of complications. This includes a stroke, organ dysfunction (where your organs do not work properly), acute chest syndrome (a lung condition causing chest pain and breathing difficulties) and infections
• puts you at risk of death.

You can only have a stem cell transplant if you have a matched related donor. This is a brother or sister (sibling) who is a full match and can donate their stem cells to you. Your sibling can still donate their stem cells if they have the sickle cell trait, but not if they also have sickle cell disorder. Find out more about sibling stem cell transplants.

There is not enough evidence yet to support having a matched unrelated donor - someone from the Anthony Nolan stem cell register, for example. This may change in the future with more research and more improvements in the transplant process.

You can ask your medical team if a stem cell transplant might be a treatment option for you. If they have not mentioned it in appointments, you can talk about it. Tell them you’re interested in finding out more.

Remmy's story

Remmy (Elizabeth), from Essex, had a stem cell transplant to cure her sickle cell disorder. Watch her story to find out about her experience. You can find chapters below the video.

What are the risks and benefits?

A stem cell transplant can cure blood cancers and blood disorders, like sickle cell disorder. That’s simply fantastic. But a transplant is an intensive treatment which comes with lots of risks and benefits to consider.

For someone with a blood cancer, like leukaemia, a stem cell transplant can be their last chance of survival. So, patients and their medical teams are likely to take more risks. It is a final treatment option.

If you’ve got sickle cell disorder, a stem cell transplant is more likely to be a treatment to give you a better quality of life, rather than a treatment for survival. This means risks are considered differently. So, it’s important for you to go through all the risks and benefits with your medical team. You need to consider if this is the best option for your individual health and future.

Benefits

• A stem cell transplant can cure your sickle cell disease.
• You can expect your pain episodes to stop, but this may take some time. You might continue to have chronic pain because of damage already done by your sickle cell disorder. Your pain management will be controlled carefully after transplant if this applies to you. This will all depend on your individual situation.
• A stem cell transplant should prevent further complications caused by your sickle cell disorder. It is likely that any sickle cell related problems with organ function that you already have, for example with your eyes, will not worsen any further.
• You can have a better quality of life. You may be offered a transplant if your severe sickle cell disorder affects your day-to-day life, and you do not respond well to any other treatments.

Risks

• Any current complications you have from your sickle cell disorder could put you at risk during a stem cell transplant. These could include liver failure or heart conditions, for example. Your medical team can talk you through how well your body could cope with a transplant.
• Graft versus host disease (GvHD) is a potentially life-threatening side effect of a stem cell transplant. This is where your new stem cells start to attack other cells in your body. You can read lots more about GvHD in this section.
  
  GvHD will not always be life-threatening and the risk of GvHD is much lower for people with sickle cell disorder. But it is a big risk to consider as sometimes GvHD can cause graft failure.
• You’ll need to have conditioning therapy before your transplant to prepare your body to receive your new stem cells. You’re more at risk of infection during this time. For people with sickle cell disorder, this is currently made up of an immunosuppressive drug and low dose radiotherapy. This is a less intense form of conditioning therapy used for other disorders, which cuts the risk of complications.

What are the other treatments for sickle cell disorder?

A stem cell transplant is the only treatment that can cure sickle cell disorder now. But there are other treatments available which can help manage your symptoms:

• Pain management can ease symptoms and help to give you a better quality of life.
• Long-term antibiotics, like penicillin, can help to prevent infections.
• Long-term blood transfusions can help to increase oxygen being carried around your body, which can prevent strokes and acute chest syndrome as well as reduce pain episodes.
• Red Cell Exchange is like a blood transfusion. But your red blood cells are removed before being replaced by red blood cells from a donor.
• Hydroxycarbamide is a medicine that can help to reduce the number of pain episodes and other complications.
• Casgevy is a gene therapy which can help stop red blood cells from turning into the sickle shape which causes pain episodes and health complications. For more information see our webpage on gene therapy and stem cells.

Not all people with sickle cell disorder can have these treatments, and they come with their own side effects. If your sickle cell disorder is severe and you are not able to have these treatments, or they simply do not work, you may be offered a stem cell transplant.

You can find out more about all treatments for sickle cell disorder on the NHS website.

What is happening with voxelotor (Oxbryta)?

Voxelotor was a drug treatment introduced to the NHS in May 2024. It was withdrawn from use worldwide by its manufacturer as a precaution on 8 October 2024. A review of data suggested the benefits of using the drug were no longer seen to outweigh the risks. The findings of the review are under investigation.

If you were taking voxelotor, you should have been told to stop by your medical team. You should also have been asked to return any unused medicine. No new patients will start treatment on the drug. Please contact your medical team for further advice.

You can read more about voxelotor being withdrawn on the Sickle Cell Society website.

What happened to crizanlizumab (Adakveo)?

Crizanlizumab (Adakveo) was a drug treatment introduced in 2020. It has now, since 10 January 2024, been withdrawn. This is due to concerns about how effective the drug is in reducing painful crises. This means no new patients will be prescribed with crizanlizumab. However, this does not mean the treatment is unsafe.

If you are currently taking crizanlizumab, please speak to your medical team to discuss alternative treatment options.

You can read more about crizanlizumab being withdrawn on the Sickle Cell Society website.

Adewale's story

Adewale, from Cambridge, had a stem cell transplant after having a severe stroke caused by sickle cell disorder. Watch his story below to find out more about his journey. You can find chapters below the video.

Why could I not have a stem cell transplant before 2020?

Adults with sickle cell disorder could not have a stem cell transplant before 2020 as there was not enough evidence to prove it was a suitable treatment option.

People with sickle cell disorder are more likely to pick up infections and have other health conditions. This can put them at higher risk of complications during or after a stem cell transplant.

Thankfully, there have been recent improvements in transplant procedures. For example, someone with sickle cell disorder needs to have a less intense conditioning therapy before their transplant. This reduces their risk of complications.

Also research has shown that if you have a sibling who is a full match and can donate their stem cells, a stem cell transplant can be a successful treatment option for someone with sickle cell disorder.

Iggie's story

Iggie had a stem cell transplant in the USA to cure her sickle cell disorder. Watch her story to find out more about her 'tough but rewarding' stem cell transplant journey. You can find chapters below the video.

What else do I need to think about when considering a stem cell transplant?

There are lots of personal issues to think about when it comes to having a stem cell transplant. Here are some ideas to consider and to talk to your medical team about.

• Currently, you can only have a stem cell transplant to cure your sickle cell disorder if you have a matched related donor, like a brother or sister. If your brother or sister is a full match, that’s fantastic. But they still need to be happy and agree to donate their stem cells for you. Read more about donating your stem cells to a relative.
• A stem cell transplant can cure your sickle cell disorder. But you will still carry the sickle cell gene. This means you could still pass it on to any children you have after transplant. You and your partner can have a test before getting pregnant to find out how likely it is that your child will have the sickle cell gene. Your GP can help organise this test. Find out more from the NHS website about how sickle cell disorder is inherited.
• Is your sickle cell disorder having a negative effect on your day-to-day life? If other treatments are not working or are not giving you the quality of life you deserve, it may be worth considering a stem cell transplant.
• Consider your individual situation and current risk to your life. Talk to your medical team about the risks to your life if you do not have a stem cell transplant, compared to the risks to your life if you do.
• Having a stem cell transplant can be a long, challenging process. You will need to have conditioning therapy before and spend a long time recovering after. Read more about recovering from a stem cell transplant.

Key facts about sickle cell disorder

• About 17,000 people in the UK have sickle cell disorder.
• Almost 300 babies each year in the UK are born with sickle cell disorder.
• You can have a blood test during pregnancy (as well as before — see above) to check if your baby is at risk of having sickle cell disorder.
• When your baby is born, they can have a sickle cell screening as part of their newborn blood spot test.
• Sickle cell disorder mainly affects people from Black African and Caribbean backgrounds.

FAQs

Where can I find more information and support?

Our Patient Services team is here for you before, during and after your stem cell transplant. We can answer questions you have about the process, support you with any worries you have, and give any practical help you need.

You can call our helpline on 0303 303 0303 or email patientinfo@anthonynolan.org. Our opening hours are 9am to 5pm, Monday to Friday.

• The Sickle Cell Society supports and represents people with sickle cell disorder. You can find lots of information and advice on their website, including their Parent’s Guide to Sickle Cell Disease. You can also get in touch with their helpline or mentoring scheme to share experiences, and find other support groups and local services.
• ACLT (African Caribbean Leukaemia Trust) is a charity spreading awareness of donor registers, including the stem cell register. They particularly encourage people from the Black and Black mixed-race community to become potential donors. They also assist sickle cell patients who need matched blood for transfusions or blood exchanges. You can find information and support, and get involved in their work, on the ACLT website.
• There’s also information about sickle cell disorder, including symptoms, treatments, and living with sickle cell disorder, on the NHS website.