Stem Cell Transplantation for Acute Lymphoblastic Leukemia

Doctors usually recommend stem cell transplantation for people with acute lymphoblastic leukemia (ALL) based on the genetic or chromosomal abnormalities found at diagnosis, the response to induction chemotherapy, or the return of cancer after treatment with standard drug therapy.

Allogeneic stem cell transplantation uses stem cells from a donor, usually a close blood relative or someone whose tissue types are a genetic match. This kind of stem cell transplantation can cure some people with acute lymphoblastic leukemia.

Before the transplant, doctors give high dose chemotherapy for a few days in the hospital, with or without radiation therapy—the use of high levels of energy beams—to destroy residual leukemia cells that might still be present. Radiation therapy is used to treat the whole body and can destroy cancer in places that chemotherapy may not easily reach. It is usually given twice daily.

In addition to destroying any remaining acute lymphoblastic leukemia, high dose chemotherapy, with or without radiation therapy, also destroys the bone marrow, which is critical in producing the cells needed for proper blood and immune system function.

After you receive chemotherapy, with or without radiation therapy, stem cell transplantation replaces damaged and destroyed bone marrow cells with healthy stem cells from the donor. Stem cells are immature blood cells found in bone marrow. They develop into red blood cells, which provide oxygen to tissue, and white blood cells, which fight infection. Stem cells can also become platelets, which help blood clot.

Doctors transfuse the donor stem cells into your body with an intravenous (IV) catheter, a narrow tube placed in a vein. This takes several hours.

The stem cells travel to the bone marrow, where, over the course of several days, they grow and eventually produce healthy blood cells and a new immune system. This new immune system may attack any remaining leukemia that was not destroyed by the high dose chemotherapy, with or without radiation therapy.

One potential drawback to using donor stem cells is that they may recognize your body as foreign—a condition known as graft-versus-host disease. This complication can be treated using immunosuppressive medications. However, the body is also vulnerable to infections because the immune system is suppressed.

Additionally, the treatments you received before the transplant cause your blood cell levels, including red and white blood cells and platelets, to drop for several days after the transplant until the donor stem cells “repopulate” the marrow and blood with healthy cells. This can make you vulnerable to infections and bleeding.

For these reasons, your doctor closely monitors you and may give you medications to prevent these complications.

After transplantation, doctors monitor you in a special isolation room within the transplant unit. While there, you receive antibiotics to prevent infection, as well as transfusions of red blood cells and platelets to manage bleeding.

In the next 10 to 14 days, the stem cells start producing new blood cells, a process called engraftment. Once blood cells have returned to their normal levels and your doctors determine you are well enough, you can go home. Because your immune system may be weak for several months and you may still experience complications such as infection, frequent follow-up appointments are necessary.

NYU Langone offers a variety of support services for people who have had allogeneic stem cell transplantation to help with recovery.