The MDS Beacon™

This article is part of a series about stem cell transplantation in MDS, which will be published over the next couple of weeks. The series will explain the different types of stem cell transplants, describe the procedure for both patient and donor, address benefits and risks, and talk about prognosis and life after a transplant.

Although stem cell transplants can cure myelodysplastic syndromes (MDS), not all patients are good candidates for the procedure. In general, the procedure is considered as a treatment option for younger patients with high-risk MDS who have a matched donor and a life expectancy that is long enough to justify the procedure, even if the procedure were not successful.

According to Dr. H. Joachim Deeg, a professor of medicine at the University of Washington, Seattle, doctors analyze the patient’s disease severity, life expectancy, response to alternative treatments, any other diseases the patient may have, and if there is a matched donor available on a case-by-case basis.

For donor, or allogeneic, transplants, the most common form of transplants in MDS patients, the procedure involves four phases: the preparation phase, the transplantation phase, the engraftment phase, and the recovery phase.

Preparation

Once a patient is determined eligible for a stem cell transplant, stem cells are collected, and the patient’s bone marrow is prepared for the procedure.

The stem cells are collected from the blood or the bone marrow of the donor and stored until the day of the transplantation (for more information on types and sources of stem cells, please see Part 1 of the series).

Once the stem cells are ready, the patient’s bone marrow is prepared for the transplant. For that purpose, the patient undergoes a preparative chemotherapy treatment.

Two different types of preparative treatment are used for stem cell transplants in MDS patients. They are known as myeloablative and non-myeloablative treatments.

Myeloablative treatments are the most common preparative treatments. They use high doses of chemotherapy or radiation therapy to completely destroy all of the patient’s stem cells. These cells do not grow back, and the patient needs donor stem cells to replace the killed cells. Common chemotherapy agents used for MDS patients are busulfan, cyclophosphamide, and etoposide.

Non-myeloablative treatments (also known as reduced-intensity or mini transplants) use lower doses of chemotherapy or radiation therapy. These low doses of preparative therapy are enough to suppress a patient’s own bone marrow without completely destroying it. The goal is to inhibit the patient’s bone marrow enough to allow the donor’s stem cells to take root in the patient’s bone marrow and grow there.

Because of the decreased intensity of non-myeloablative chemotherapy, this therapy is used in older patients, patients with chronic diseases, or patients who are not healthy or strong enough to undergo standard preparative treatment.

Transplantation

After the preparative regimen is complete, the patient receives the donated stem cells.

The stem cells are given to the patient intravenously through a central line into a large blood vessel. The donor stem cells circulate in the patient’s bloodstream and go to the patient’s bone marrow.

The transfusion process normally takes several hours, during which the patient is checked frequently for signs of side effects and complications, such as fever, chills, hives, a drop in blood pressure, or shortness of breath. Side effects, which are rare during the transfusion process, are treated upon completion of the infusion.

Engraftment

After receiving a stem cell transplant, the patient is monitored for signs of engraftment. Engraftment, a sign of a successful transplant, means that the donated stem cells are reproducing and making new blood cells in the patient’s body.

The patient has blood taken daily. The samples are given a complete blood count test (CBC). A CBC indicates the number and type of blood cells in the bloodstream.

The two types of blood cells that are monitored the closest are neutrophils, a type of white blood cell, and platelets, cells that help with blood clotting.

Engraftment is indicated by a neutrophil count greater than 500 for three days and a platelet count in the range of 20,000 to 50,000 per liter of blood.

It typically takes about 20 days for the body to produce these quantities of neutrophils and platelets after undergoing a stem cell transplant.

Recovery

Recovery from a myeloablative stem cell transplant can include staying in the hospital after the transplant for about three to four weeks.

After being released from the hospital, patients may need to remain within a one-hour drive of the hospital for about 100 days after the transplant. The patient then continues to recover at home for three to six months after the transplant.

Patients who undergo a mini stem cell transplant may have to stay within a one-hour drive of the hospital for at least 30 days after the transplant.

Follow-up care during recovery includes appointments with the patient’s transplant physician or local physician to evaluate the patient’s recovery and monitor any signs of complications or infections.

For more information on the benefits and risks of stem cell transplants, and the experiences of MDS patients who have received a stem cell transplant, please see the subsequent articles in the series, which will be published over the next few weeks.