Myelodysplasia typically takes one of two directions in its clinical course:
- Progressive anemia and other cytopenias, in which the faulty machinery producing red blood cells, white blood cells and platelets leads to a scarcity of normal blood cells of these types.
- Malignant transformation to AML, in which abnormal immature blast cells (which cannot differentiate into normal blood cells) crowd out the normal cells, creating acute leukemia.
Blood transfusions are often used to treat anemia-based myelodysplastic syndromes, or MDS. By regularly transfusing appropriately-typed donor blood into the anemic patient, normal levels of red blood cells are restored, and symptoms of anemia can be controlled. Platelet transfusions may also help in cases of platelet deficiency (thrombocytopenia).
Certain compounds, known as growth factors, are known to stimulate the development of specific types of blood cells. In recent years, genetic engineering techniques have made it possible to produce “recombinant human growth factors,” which – although produced in the laboratory – are chemically identical to the compounds produced by the human body.
Stem Cell Transplantation
Hematopoietic cell transplantation and peripheral blood stem cell transplantation use stem cells (immature blood cells) as part of the treatment of a bone marrow disorder. Because myelodysplasia is a bone marrow disorder, stem cell transplantation offers a way to attack the disease at its root. City of Hope is a widely-acknowledged leader in stem cell transplantation and has developed many innovative transplantation protocols to improve patient outcomes.
Transplant procedures include intensive chemotherapy with or without radiation therapy first to ablate (destroy) the abnormal cells, followed by an infusion of healthy new cells.
Allogeneic transplants use stem cells from a matched donor. Sometimes, a sibling or other close relative is an ideal donor, but in many cases, a matched unrelated donor with a similar genetic type as the patient will be used.
The new, transplanted stem cells produce normal (as opposed to dysplastic) red blood cells, white blood cells and platelets. The “new immune system” that has been transplanted should also fight the proliferation of malignant clones. This is known as the “graft-versus-tumor” effect.
In autologous (self) transplants, a patient’s own stem cells are collected and frozen ahead of time. This eliminates the risk of graft-versus-host disease, as the graft and the host are one and the same. Typically, stem cells are collected from peripheral blood. After the cells have been stored, intensive chemotherapy and/or radiation treatments are given to destroy any malignant or abnormal cells remaining in the body. Then, the healthy stem cells are infused back into the patient.
As these new stem cells grow, they should produce normal blood cells. However, autologous transplantation is not preferred in myelodysplasia, as the autologous cells may contain the transformed malignant clone.
Standard chemotherapy may also be utilized in treating myelodysplasia.
Research and Clinical Trials
City of Hope has long been a leader in myelodysplasia research, including promising new combinations of chemotherapy drugs, immunomodulators and stem cell transplant procedures. With our extensive program of clinical trials, City of Hope can provide our patients access to novel therapies, including many of those discussed above, that are not yet available elsewhere.
To learn more about our clinical trials program, click clinicaltrials.coh.org.