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Stem cell transplant for chronic myelogenous leukemia
A stem cell transplant is sometimes used to treat chronic myelogenous leukemia (CML). Stem cells are found in the bone marrow, the bloodstream and umbilical cords. They are basic cells that develop into different types of cells that have different jobs. For example, all our blood cells develop from blood stem cells.
A stem cell transplant is used to replace stem cells when stem cells or bone marrow are damaged. They can be damaged by disease or destroyed by high doses of chemotherapy or radiation therapy.
A stem cell transplant is a very risky and complex procedure that must be done in specialized transplant centres or hospitals. Many people cannot have this treatment because they are older, they have other health problems or there isn’t a suitable donor for them. You may be offered a stem cell transplant if:
- you are young, have no other health problems and have an HLA-matched donor
- you did not reach a complete remission (the blood cell counts have returned to normal and stay at or near normal levels for long periods of time)with targeted therapy or interferon alfa (Intron A, Wellferon)
- you develop resistance to or you relapse with targeted therapy or interferon alfa
The side effects of the high doses of chemotherapy used before a stem cell transplant may be too severe for people over 55 years of age. People in this age group may also have other health conditions that mean they can’t have a standard stem cell transplant. They may be offered a reduced-intensity transplant, which uses lower-dose conditioning treatment.
Types of transplants used for CML
The following types of stem cell transplant may be used with CML.
In this type of transplant, the stem cells are taken from one person (the donor) and are given to another person (the recipient). The donor may be a relative or may be unrelated to the recipient. The donor and recipient are matched through a process called human leukocyte antigen (HLA) typing.
An allogeneic stem cell transplant is the only treatment known to cure CML. But not everyone can have an allogeneic transplant because they need to have a matched donor.
In this type of transplant, the stem cells are taken from your own bone marrow or blood. Sometimes an autologous transplant is an option for CML in the accelerated or blast phase if there is not a matched donor.
Donor lymphocyte infusion
A donor lymphocyte infusion (DLI) may be given if CML relapses after an allogeneic stem cell transplant. Before a stem cell transplant, lymphocytes are removed from the donor’s blood and frozen for storage. If a relapse occurs after a stem cell transplant, the lymphocytes are thawed and given to the person through one or more infusions. DLI may boost the immune system and bring on a stronger immune reaction against the CML cells.
Side effects can happen with any type of treatment for CML, but everyone’s experience is different.
Side effects can develop any time during, immediately after or a few days or weeks after a stem cell transplant. Sometimes late side effects develop months or years after a stem cell transplant. Most side effects go away on their own or can be treated, but some side effects may last a long time or become permanent.
Side effects of a stem cell transplant will depend mainly on the type of chemotherapy drug or drug combination given, if radiation therapy was given, the type of transplant and your overall health. Common side effects of a stem cell transplant include:
- low blood cell counts (called bone marrow suppression)
- skin problems
- hair loss
- graft-versus-host disease (GVHD)
- veno-occlusive disease
Tell your healthcare team if you have side effects that you think might be from a stem cell transplant. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.
Questions to ask about stem cell transplant
A condition that might happen after a stem cell transplant. Healthy stem cells from a donor (called the graft) attack a recipient’s (receiver’s) cells (called the host). The graft cells see the host cells as foreign and start to destroy them. Symptoms include jaundice, rash or blisters on the skin, dry mouth or dry eyes.