What is the process of receiving a stem cell transplant?
Siblings from the same mother and father are the best source of stem cells for the transplant. These siblings are screened to see if their stem cells match the patient by a process called human leukocyte antigen (HLA) typing.
Once the sibling donor is identified:
- Both the sibling donor and patient with sickle cell disease undergo blood, heart, and lung screening tests to make sure they are physically prepared for the transplant.
- The sibling donates the stem cells through a process similar to blood donation. The sibling is given an injection that he/she can take at home and is administered under the skin (similar to insulin for a diabetes patient) for 5 days.
- After the fifth day, the sibling comes to the donor room at UI Health and has an IV placed.
- The stem cells are then collected just as if someone were donating blood.
- The process of collecting stem cells in the donor room takes approximately 3 to 4 hours.
Once the patient recipient is ready for stem cell transplantation and a date is set:
- The patient is admitted to the stem cell unit on 8 West of the University of Illinois Hospital.
- An intravenous catheter (small tube) called a central line is placed in a large vein in your body using an x-ray.
- An exchange transfusion is done, where the body's sickle red blood cells are removed and non-sickle red blood cells are transfused through the central line.
- The patient receives 5 doses of Campath, an immunosuppression medicine, and one low dose of radiation. Campath and radiation are used to prevent the immune system from rejecting the transfused stem cells.
- The stem cells will be infused in a process similar to a blood transfusion through the central line over approximately 1 to 2 hours.
- The patient stays on 8 West until all of the blood counts are in a safe range - usually about 3 weeks total. There is a possibility that the patient may need transfusions and antibiotics during that period.
- The patient will take an anti-rejection medication, Sirolimus, to help prevent rejection of the stem cells starting a few days before the stem cell transfusion.
- After discharge, the patient will have close follow-up with both the Stem Cell Transplant Team and with the Sickle Cell Center.
- The patient will continue to take Sirolimus for a long period of time - perhaps months or years - but eventually may be able to discontinue the drug.
- The patient will no longer need to be on hydroxyurea.
What are the risks of stem cell transplantation?
Infection: Since the immune system is weakened, in order to allow cells to be accepted, infection is a potential risk. Especially in the period soon after transplant, it will be important to avoid sick people and contact your doctor if you feel like an infection is starting so that you can be started on antibiotics promptly. The immune suppression from Sirolimus increases the risk of certain types of infection.
Graft-versus-host disease: The donated stem cells can potentially attack your body and cause rash, diarrhea, and other complications. This can be mild to severe and occur months to years after the transplant. You will be closely monitored by your doctor for signs and symptoms of this.
Toxicity from the medications: The Sirolimus can cause joint aches or lung changes.
Rejection: In about 10% of the patients who receive a transplant, the donor stem cell may not engraft (their bodies do not accept the donor's stem cells) or remain in the recipient's marrow and the patient will go back to their status prior to transplant. Our team will closely monitor the donor and recipient cells in the blood for at least one year following transplant. Immunosuppression therapy may be modified based on these results.