Stem cell transplantation (bone marrow transplantation) is a complex process that may take months to complete. Your doctors, nurses and the transplant patient coordinator will review information about your child's stem cell transplant during the consent meeting, daily rounds and visits to the Jimmy Fund Clinic. A general description of the stem cell transplantation process follows.
Children eligible for stem cell transplantation will have several preliminary appointments, including tests and blood work, scheduled before being admitted for transplant. These pre-transplant evaluations and appointments will be scheduled by our Stem Cell Transplant Patient Coordinator, who acts as your liaison to the clinical team. You will also meet with a senior member of the transplant team to discuss the plan for your child in depth and to sign the transplant consent form.If your child is receiving an autologous (self) peripheral blood stem cell transplant, we will collect his/her stem cells before admitting your child for transplant. Stem cells are collected at the Apheresis Therapeutic Unit at Boston Children's Hospital. Stem cell collection is coordinated with your care provider and the Stem Cell Transplant Patient Coordinator.
Patients are admitted to 6 West, the stem cell transplantation unit at Children's. Your child may be admitted in one of three ways:
The Stem Cell Transplant Patient Coordinator will arrange your child's admission.
Conditioning therapy refers to the high-dose chemotherapy and/or radiation that children receive before their stem cell infusion. The day your child receives the bone marrow or stem cells is called Day Zero (Day 0). The days prior to Day 0 are the days that a patient receives the conditioning therapy. These days are referred to with negative numbers, for example Day -7, Day -6 or Day -5. There are several goals of conditioning therapy:
If your child is receiving cells from another person, conditioning therapy has a third goal: To suppress your child's immune system so it will not reject the donor's cells
Day 0 is the day the stem cells are infused. Stem cells are infused through the child's central venous line.
After Day 0, the days are referred to with positive numbers, for example Day +1, Day +2 or Day +3. Patients may begin to have some of the expected side effects of the conditioning therapy such as nausea, vomiting, diarrhea and mouth sores.
Stem cell transplantation patients are at high risk for infections because the immune system is suppressed from the conditioning therapy. Patients who receive stem cells from another person have an additional risk for infection since they take medications that suppress the new immune system. Patients need these immunosuppressive medicines in order to help prevent graft-versus-host disease (GVHD).
After the marrow has been infused, the number of white blood cells and neutrophils, a certain type of white blood cell, increase over the next two to four weeks. Engraftment occurs when the stem cell graft is making enough neutrophils to offer some protection against bacterial infections.
If your child receives stem cells from someone else, there is a risk of graft-versus-host disease (GVHD). GVHD may occur before or after stem cell engraftment. It is caused when the donor's (graft) T lymphocytes, a type of white blood cell, react against the cells of the patient (host). Therefore, the condition is called graft (donor)-versus-host (patient) disease. The patient is most likely to show the effects of GVHD in the skin, the gastrointestinal tract (digestive system) and the liver. In general, acute GVHD occurs before Day +100 and chronic GVHD occurs after Day +100.
The conditioning therapy and medications used during transplant may cause other side effects and toxicities, which will be discussed during your initial consent meeting. Our doctors and nurses will explain these problems, and the recommended treatments, if they occur. Blood tests, X-rays, CAT scans, MRI scans, ultrasounds or biopsies (tissue samples) of certain tissues may help in the diagnosis of such problems.
A child may be discharged after engraftment has occurred. He or she must also be medically stable and able to take the required medications.
Autologous (self) transplant patients should not attend school or visit other public indoor places for six months after transplant. Allogeneic (related and unrelated donor) transplant patients should not attend school or visit indoor public places for nine to 12 months after transplant, depending on the patient's status. We will provide you and your family with educational materials upon discharge that review common post-transplant issues.
Leslie Lehmann, MD, explains stem cell transplants. Dana-Farber/Boston Children's has one of the most experienced pediatric stem cell transplant programs in the United States.