Most people are at least somewhat familiar with stem cells from having heard about them on the news, even if they aren’t entirely sure what they really are. What makes them different from other cells is that rather than having a specialized role, stem cells have no specific function whatsoever and actually have the ability to develop into other types of cells. Additionally, they can continue replicating for long periods under the right conditions, producing even more stem cells. Because of these unique characteristics, there is great potential in transplanting them into the body to help regenerate and repair tissues damaged by the effects of disease.
Among the many medical uses for stem cells, the treatment of leukemia is one area where results have been quite successful. When a person develops leukemia, cells in the bone marrow mutate in such a way that they begin to divide and multiply rapidly, rather than dying when they’re supposed to. This crowds out the normal and healthy cells, which will eventually die off.
There are currently two types of stem cell transplants used in the treatment of leukemia:
Allogeneic Stem Cell Transplant
An allogeneic transplant involves locating a matching donor, from which stem cells can be taken. Ideally this would be a sibling with a similar genetic makeup, although it is sometimes possible to use cells from a matching unrelated person, a miss-matched family member and even umbilical cord stem cells from a cord blood bank. In any case, the patient is given a human leukocyte antigen (HLA) test, to test the patient’s blood and tissue against that of the donor.
The patient first undergoes a vigorous treatment regimen, designed to kill as many leukemic cells as possible, before the transplant. This typically includes intense chemotherapy and even radiation therapy, in certain cases. Depending on the individual needs of the patient, a type of reduced-intensity treatment might also be used instead, that requires lower doses of chemotherapy drugs and/or radiation.
Once the treatment is complete, the transplant begins. The cells are received intravenously in a procedure that takes around an hour and is similar to a blood transfusion. Once the stem cells have entered the bloodstream, they head straight for the bone marrow and begin the producing new cells to replace the ones destroyed in treatment. Over a period of several months, blood counts are checked repeatedly to monitor the ongoing regeneration process, which is known as “engraftment.”
Autologous Stem Cell Transplant
In an autologous stem cell transplant, the patient’s own stem cells are used, having been harvested before the treatment and kept in frozen storage until after the treatment process. This type of transplant is considerably rare in the treatment of leukemia, although the rest of the procedure is essentially the same.
Regardless of which type of transplant the patient receives, recovery will still take a considerable amount of time as the new cells grow, allowing the body to gradually heal itself. There’s also the potential for certain side effects, including infections and even the possibility that the new stem cells might actually attack the patient’s own tissues. In addition to certain medications prescribed to prevent these conditions, a patient is also given a special meal plan and exercise program, along with a support team committed to their ongoing rehabilitation.