If your treatment plan for paroxysmal nocturnal hemoglobinuria (PNH) isn’t working as well as you’d like, you may wonder whether a bone marrow transplant could help. While complement inhibitor medications like eculizumab (Soliris), iptacopan (Fabhalta), pegcetacoplan (Empaveli), and crovalimab-akkz (PiaSky) are effective treatment options for many people with PNH, those who have severe symptoms or bone marrow failure may still have problems with their quality of life.

Bone marrow transplants are the only type of treatment that can potentially cure PNH completely — but they aren’t suitable for everybody. These procedures can lead to severe — and sometimes life-threatening — side effects. However, some people who undergo bone marrow transplants experience good outcomes and live a long time with PNH.

How Do Bone Marrow Transplants Work?

Bone marrow transplants can reverse the underlying cause of paroxysmal nocturnal hemoglobinuria.

PNH symptoms are the result of problems in your bone marrow — the soft, spongy tissue found inside certain bones. Your bone marrow contains cells that make all the other cells in your blood, including red blood cells, white blood cells, and platelets. If you have PNH, your bone marrow contains damaged cells that don’t produce enough healthy blood cells.

During a bone marrow transplant, abnormal marrow is replaced with healthy marrow. For the treatment of PNH, doctors use a type of transplant called an allogeneic bone marrow transplant, in which the healthy bone marrow comes from a donor. This process involves multiple steps:

1. A doctor collects bone marrow from a family member or a stranger who happens to have some of the same genes that you do.
2. Your bone marrow is treated with a conditioning regimen — high doses of radiation or chemotherapy that kill your damaged bone marrow cells.
3. You receive an intravenous infusion of the donor’s bone marrow.
4. The donated cells travel to your bone marrow, where they start making healthy blood cells.

It typically takes a long time to recover from a bone marrow transplant. It may be up to a year before you start feeling like you used to. During your recovery, you’ll need to rest and take care of yourself, attend any follow-up appointments, and take any medications that your doctor gives you, such as anticoagulants to prevent blood clots.

How Is a Donor Chosen?

In the past, doctors would collect donated bone marrow from someone who was a matched unrelated donor — a stranger whose blood cells contained the same types of proteins on the surface as yours.

However, recent research suggests that results are likely to be similar whether the marrow comes from a fully matched stranger or a haploidentical (partially matched) family member. This means that it may be easier for you to go through with a bone marrow transplant because you don’t need to wait to find a perfect match.

When Are Bone Marrow Transplants Used To Treat PNH?

Bone marrow transplants are most often recommended for younger people with paroxysmal nocturnal hemoglobinuria whose bodies might recover more easily from the stress of the procedure.

Additionally, a bone marrow transplant may be an option only if you have very severe PNH. Because transplants can lead to serious side effects, the risks are often not worth the benefits if you have a milder case.

Your type of PNH is also a consideration. Do you have classic PNH, in which only your red blood cells are abnormal? Eculizumab treatment is likely to work well for you, and your doctor will be less likely to suggest a bone marrow transplant.

However, your health care provider will be more likely to suggest a transplant if you have PNH with bone marrow failure, in which you are also diagnosed with a condition that affects multiple types of blood cells. You may have related conditions such as aplastic anemia, myelodysplastic syndrome, and primary myelofibrosis.

How Effective Are Bone Marrow Transplants?

Bone marrow transplants often accomplish their main goal: replacing damaged marrow with healthy marrow. According to one study, about 6 percent of bone marrow transplants fail to engraft — in other words, the donated cells never begin growing successfully in the bone marrow and don’t produce new blood cells. On the rare occasion that you don’t have good engraftment, your doctor may recommend a second transplant.

Older studies showed that people with paroxysmal nocturnal hemoglobinuria who underwent a bone marrow transplant often had a poor prognosis (outlook). However, newer research looking at data from people treated with improved therapies has reported better results. For example, multiple newer studies have found that 7 out of 10 people with PNH lived for five years or more after receiving a bone marrow transplant. When people don’t survive transplants, it’s often due to issues such as severe infection, bleeding problems, or graft-versus-host disease (GVHD), a condition described below.

For some people, a bone marrow transplant can lead to a cure for PNH — you no longer experience symptoms nor need additional therapies. In a study of 78 people diagnosed with PNH, bone marrow transplants eliminated all detectable PNH cells in about half of people with classic PNH and 84 percent of those who also had bone marrow failure.

How effective will a bone marrow transplant be for you? It depends on multiple factors, including your age, your overall health, your other treatments, and how well your donor’s cells match yours. Talk to your doctor if you’d like to learn more about whether this procedure may be successful for your case of PNH.

Risks of Bone Marrow Transplants

Bone marrow transplants sometimes lead to short-term side effects, such as:

• Fever or chills
• Hives (an itchy rash)
• Nausea
• Low blood pressure
• Chest pain
• Headache
• Shortness of breath

Graft-Versus-Host Disease

In a study published in the journal Blood, about 1 out of 4 people with paroxysmal nocturnal hemoglobinuria developed acute (short-term) GVHD, while one-third had chronic (ongoing) GVHD. Graft-versus-host disease occurs when your immune system finds your donated bone marrow cells and views them as a threat. Usually, this type of reaction is desirable — it’s how your immune system protects your body from bacteria, viruses, and other foreign substances. However, when your immune system attacks your donated bone marrow cells, it can lead to severe problems.

GVHD can cause symptoms including:

• Rash
• Nausea
• Vomiting
• Diarrhea
• Jaundice (yellowish appearance of skin or eyes)
• Hair loss
• Swelling
• Mouth sores
• Dry eyes
• Breathing difficulties
• Coughing
• Tiredness
• Muscle cramps

These symptoms may be mild and disappear quickly, or they can be severe enough to warrant a hospital stay. In some cases, GVHD can be life-threatening, so it’s important to tell your doctor if you have any health changes after undergoing an allogeneic bone marrow transplant. Your doctor will likely also put you on immunosuppressive therapy — medications that calm your immune system response and reduce your risk of GVHD.

Other Complications of Bone Marrow Transplants

Complications — health concerns that develop during a disease or its treatment — can sometimes arise after a bone marrow transplant. Possible complications of bone marrow transplants include:

• Frequent or severe infections
• Anemia (low levels of red blood cells)
• Bleeding problems, including abnormal bleeding in the digestive tract or brain
• Thrombosis (blood clots)
• Inflammation of the tissue in the inside of your mouth, throat, or stomach
• Damage to your heart, liver, or kidneys
• Cataracts (clouding of the lens in your eye)
• Early menopause

Before you undergo a bone marrow transplant, there’s no way to tell for sure if you will experience any of these issues. However, you may be more likely to develop post-transplant complications if you are older, have underlying health conditions besides PNH, or received donated cells from someone who wasn’t a great match.

It’s important to recognize that PNH itself can also come with a shortened life span, especially if you develop blood clots or conditions such as myelodysplastic syndrome or acute myeloid leukemia. If you’re a candidate for a bone marrow transplant, your doctor will help you weigh all of the potential risks versus benefits.

Minimizing Complications After a Bone Marrow Transplant

You can take steps to reduce your chance of experiencing side effects and complications of a bone marrow transplant. In addition to following all your doctor’s instructions, you may want to try:

• Avoiding germs by regularly washing your hands, especially after using the bathroom, before touching food, or after being outside
• Minimizing your risk of infection by ensuring your food is cooked properly and asking your doctor which vaccinations you may need
• Brushing your teeth two or three times a day and flossing once daily to maintain oral health
• Rinsing your mouth multiple times per day with a solution containing baking soda to help treat sores, ulcers, or swelling
• Watching out for bleeding problems such as frequent nosebleeds, bloody gums, cuts that take a long time to heal, or heavy menstrual periods
• Building your strength and energy by eating extra calories and protein
• Staying active to the extent that you’re able, including taking a daily walk
• Limiting how much alcohol your consume or avoiding it entirely
• Quitting smoking

Building Your Support Team

On myPNHteam, the social network for people with paroxysmal nocturnal hemoglobinuria and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with PNH.

Have you discussed bone marrow transplant with your doctor as a way to treat your PNH? If you have had this procedure, what strategies did you follow to avoid complications? Share your experience in the comments below, or start a conversation by posting on your Activities page.