Allogeneic stem cell transplantation uses donor stem cells to treat and sometimes cure certain blood disorders and blood cancers. Healthcare providers typically recommend stem cell transplantation if initial treatments don’t work or if conditions have come back. About 50% of people who need stem cell transplantation use stem cells donated by someone who’s not a family member.
Healthcare providers use allogeneic stem cell transplantation to treat blood cancers and sometimes cure certain blood disorders. Providers may recommend allogeneic stem cell transplantation if initial treatments didn’t work or treatments worked but the condition has come back. In allogeneic stem cell transplantation, healthcare providers replace unhealthy stem cells with donated healthy stem cells. These new stem cells produce healthy new blood cells. Many people who need stem cell transplantation use stem cells donated by someone who’s not a family member.
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Allogeneic stem cell transplantation uses donated stem cells. These stem cells may come from a family member, from someone you don’t know or from umbilical cord blood. (Umbilical cord blood is blood collected from the umbilical cord and placenta after a baby is born.) An autologous stem cell transplantation uses your own blood stem cells.
While both treatments help your bone marrow to develop new blood cells, studies show allogeneic stem cell transplantations work by causing the donor cells to attack unhealthy cells. Healthcare providers call this “graft-versus-tumor” effect (GVT).
Healthcare providers use allogeneic stem cell transplantation to replace unhealthy cells that cause conditions, including:
Many times, allogeneic stem cell transplantation cures the following blood disorders:
Studies show allogeneic stem cell transplantations cure the following rare inherited blood disorders:
Healthcare providers consider several factors before recommending allogeneic stem cell transplantation to treat blood disorders or cancer. Those factors include:
The best possible match is a healthy donor who has human leukocyte antigens (HLA) that are a close match to yours. HLA are blood proteins. Healthcare providers identify HLA with blood tests comparing your HLA with your prospective donor’s HLA. This is HLA typing.
Providers evaluate donor stem cells by the number of antigens that match yours. A high number of matching antigens increases the chance the donated stem cells will make healthy new blood cells through a process called engraftment. In engraftment, donated stem cells produce new blood cells to replace the unhealthy blood cells.
Close HLA matches also reduce the risk you’ll develop acute or chronic graft-versus-host disease (GVHD). Acute GVHD symptoms may develop a few weeks after your procedure and affect your skin, liver and gastrointestinal tract.
Chronic GVHD symptoms can happen within weeks or several years after your transplantation. In addition to acute GVHD symptoms, chronic GVHD may affect your mouth, lungs, neuromuscular system or genitourinary tract.
People inherit their HLA from their biological parents. If you have biological siblings, there’s a 1 in 4 chance any one of your siblings will be HLA-matched for allogeneic stem cell transplantation.
Recently, healthcare providers have found a way to perform allogeneic stem cell transplantations s using stem cells donated by people who are only partially HLA-matched. These are haploidentical (half-match) stem cells. That means that a person who needs stem cell transplantation may be able to use stem cells donated by their biological children or their biological parents. This is a relatively new treatment that providers started using to increase the pool of potential donors.
About 70% of people who need transplantation won’t find a matching donor in their family. When that happens, providers turn to stem cell databases or registries for potential unrelated donors. Unrelated donors are people who volunteer to have their HLA type added to donor databases. Most matched stem cells come from unrelated donors.
People who want to donate stem cells work with donation registries to see if they’re eligible to donate stem cells. Typically, registry staff will ask questions to confirm prospective donors are healthy enough to make donations and that their donated stem cells won’t pose an infection risk.
Next, prospective donors take blood tests to identify their HLA type. Registry staff add those results to databases providers use to find potential matches for people who need stem cell transplantations. It’s important to remember registering with the donor database isn’t an obligation to donate.
If a prospective donor and recipient have matching HLA, providers explain the transplantation process, including risks. Providers ask prospective donors to sign consent forms stating they understand the process and risks.
Providers then complete physical examinations and blood tests to confirm the prospective donors are in good health and able to manage the bone marrow harvest procedure or peripheral stem cell harvest procedure.
Here are two options your provider may recommend using:
More than 8,000 people in the United States received allogeneic stem cell transplantations in 2020. More people received stem cells from someone outside their family than from a family member.
To understand how allogeneic stem cell transplantation works, it may help to know more about stem cells and their role in your body.
If you’re a candidate for stem cell transplantation, your healthcare provider will perform tests to confirm you can manage procedure side effects, including high-intensity chemotherapy done before your transplantation. These tests may include:
Your provider may place a central venous catheter (CVC) in one of the large veins in your upper chest. CVCs are tubes that serve as central lines that providers use to take blood and provide medication and fluids. CVCs eliminate repeated needle sticks to draw blood or insert intravenous tubes throughout the transplantation process.
Transplantation conditioning is intensive chemotherapy and/or radiation therapy that kills cancer cells in your bone marrow. Conditioning also kills existing blood cells. Donor cells replace cancer cells and healthy cells.
Providers use your CVC to insert donated stem cells into your bloodstream. Those donated stem cells make their way to your bone marrow so they can start producing new blood cells.
You’ll stay in or close to the hospital so your healthcare providers can monitor your recovery and provide any treatment you may need. Here’s what you can expect after your allogeneic stem cell transplantation:
Allogeneic stem cell transplantation may help someone who doesn’t have enough healthy stem cells for autologous stem cell transplantation. Both allogeneic and autologous stem cell transplantations replace unhealthy cells with healthy cells. Studies show allogeneic stem cell transplantation also kills cancer cells while restoring bone marrow and blood cell health.
Potential complications vary based on your overall health, age and previous cancer treatments. Allogeneic stem cell transplantations can result in graft-versus-host disease. This happens when your immune system attacks normal cells post-transplant. If you’re considering an allogeneic stem cell transplantation, your healthcare provider will outline potential complications so you can weigh those risks against potential benefits.
It may take a few months to recover from the transplantation process, including recovering from the pre-transplantation conditioning. It may take a year or two for your immune system to recover while your new stem cells make new blood cells.
It’s difficult to provide an overall success rate because healthcare providers use allogeneic stem cell transplantation to treat many different kinds of blood cancers and blood disorders. That said, recent studies show the following:
People who had allogeneic stem cell transplantations are more likely to develop graft-versus-host disease (GVHD) than people who had autologous stem cell transplantations. Contact your healthcare provider if you have the following acute GVHD symptoms:
It’s important to remember your immune system likely will be weak for a year or so after your transplantation. Contact your provider if you develop any of the following symptoms:
A note from Cleveland Clinic
More and more people who have blood disorders or blood cancer are relying on the kindness of strangers. About 70% of people who need stem cell transplantation won’t find a matching donor in their family. Fortunately, many of those people receive stem cells from unrelated donors. (People who can’t use donor cells still have options. They may find matching stem cells in donated umbilical cord blood. Recently, some people have used family members’ stem cells that match half of their stem cells.)
There are risks involved when you receive stem cells from an unrelated donor. If you’re a candidate for stem cell transplantation, ask your healthcare provider about the benefits and risks of allogeneic stem cell transplantation. They’ll explain the process and help you weigh the risks and benefits.
Last reviewed by a Cleveland Clinic medical professional on 04/19/2022.
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