There are two major types of leukemias, acute and chronic. Acute leukemia may involve either lymphocytes, called acute lymphoblastic leukemia (ALL), or myeloid cells, called acute myelogenous leukemia (AML). There are many different types of ALL and AML depending on the particular cell that has become malignant. Chronic leukemia primarily affects the myeloid cells in the bone marrow, called chronic myelogenous leukemia (CML), and is found more commonly in adults, although children and teenagers also can sometimes develop CML.

There also is a disorder of the bone marrow known as myelodysplastic syndrome (MDS), which is often associated with low blood cell counts and increased requirements for transfusions. This is often called a pre-leukemia syndrome because patients with MDS have a significantly increased risk of developing leukemia.

Treatments

We use allogeneic bone marrow stem cell transplantation to treat a variety of childhood leukemias or cancers and MDS that involve the cells within the bone marrow, also referred to as hematopoietic cells. In an allogeneic transplant, another person's bone marrow cells are used to restore bone marrow after high dose chemotherapy and radiation therapy.

• Advantage — The advantage of an allogeneic transplant over an autologous transplant — where the child's own bone marrow cells are infused to restore bone marrow function — is that it provides a "graft-versus-leukemia effect" when the other person's healthy bone marrow kills residual leukemia cells and decreases the patient's chance of relapse.
• Disadvantage — The disadvantage of an allogeneic bone marrow stem cell transplant is the risk of graft-versus-host disease (GvHD), which is when the other person's bone marrow attacks the recipient's body and causes a disease that affects the skin, liver and many other organs, requiring therapy with immunosuppressive drugs.

High-Risk Leukemias in First Remission and Myelodysplastic Syndrome

The UCSF Benioff Children's Hospital Bone Marrow Transplant Program provides transplantation for high-risk leukemia patients in first remission when a matched donor is available. In very high-risk patients, such as patients with leukemia who fail to achieve first remission with chemotherapy, an unrelated donor transplant can be done as soon as remission is achieved.

Those eligible include:

• Children with acute myelogenous leukemia (AML)
• Children with high-risk lymphoblastic leukemia (ALL)
• Infants with leukemia

In addition, children with myelodysplastic syndrome are eligible for transplant as soon as the diagnosis is established. Also selected children with leukemia may be considered for a transplant even if they are not in a complete remission.

Relapsed Leukemias in Children

Bone marrow stem cell transplantation is the treatment of choice for many children with acute leukemias whose leukemia has relapsed. The UCSF Benioff Children's Hospital BMT Program offers transplantation from:

• Related donors including brothers, sisters, parents and occasionally more distant relatives such as cousins and grandparents
• Matched unrelated donors, including umbilical cord blood

The transplant can be preformed for children with relapsed leukemia once the leukemia is in remission, which is when no leukemia is seen in the bone marrow. Remission can be achieved using chemotherapy and total body irradiation and chemotherapy. This is called the conditioning regimen and is performed prior to transplantation.

Our program also offers research protocols that look into decreasing the recurrence rate of leukemia by using additional donor T cells after the transplant.

Chronic Myelogenous Leukemia

Children with chronic myelogenous leukemia who cannot be put into complete remission with drugs, should undergo a transplant from a related or unrelated donors as early as possible in the course of the disease. Currently, we offer a research protocol that utilizes an optimal dose of a potent chemotherapy drug called Busulfan along with Fludarabine, a drug that effectively prevents rejection of the donor cells with a reduced intensity regimen.

Reviewed by health care specialists at UCSF Benioff Children's Hospital.
Last updated June 17, 2010