Aplastic Anemia - Cancer Institute Overview
The Bone Marrow Failure Clinic of the Taussig Cancer Institute is a subspecialty clinic with expertise in aplastic anemia, myelodysplasia, single lineage cytopenias, paroxysmal nocturnal hemoglobinuria, large granular lymphocytic leukemia and other immune-mediated hematologic diseases.
Our clinic provides a full diagnostic spectrum, and access to the most advanced treatments. Appointments can be made for second opinions and consultations. Patients will obtain insightful information about their disease, its prognosis, standard and experimental therapies and also, if needed, referrals to leading experts in appropriate areas of hematology. The Bone Marrow Failure Clinic offers collaborations and referrals to Leukemia, Lymphoma and Myeloma Programs of the Cleveland Clinic Taussig Cancer Institute.
What is aplastic anemia?
Aplastic anemia (AA) is a rare disease that occurs because the bone marrow is not making sufficient blood cells. The bone marrow is a tissue in the center of the bones. The bone marrow produces three type of blood cells:
- Red cells: The blood cells that carry the oxygen to all parts of the body.
- White cells: The blood cells which fight infections.
- Platelets: The small cells that help in the clotting process when we have any kind of bleeding.
These three cell types originate or differentiate from one cell type called stem cells, which exist in the bone marrow and keep dividing to make enough blood. Patients with AA do not have enough stem cells in their bone marrow to secure normal blood production.
How is aplastic anemia diagnosed?
Diagnosis is usually made based on symptoms and results from the history and physical examination your doctor performs, in addition to results from a few other tests. These include:
- Complete blood count (CBC) A blood sample is taken usually from a patient’s vein in the arm.
- Bone marrow aspiration and bone marrow biopsy which allow the physician to look at a sample of bone marrow under the microscope and provide the most precise and reliable information necessary to make the diagnosis of AA.
Aplastic anemia classification
AA is divided into 2 categories:
Moderate AA is diagnosed in those patients with significant reduction in blood counts, but not to the same degree as severe AA. Patients may not be symptomatic with this level of AA and doctors may elect not to begin treatment until patients are symptomatic or progress to severe AA.
Severe AA is defined by a less than 25 percent cellularity on the bone marrow biopsy, and at least two of the following laboratory findings. The neutrophil count - one element of the white cells – being less than half a billion in a liter of blood, or 500 cell/mm³, platelets less than 20,000/mm³, and the reticulocyte count (red cell babies) being less than 40,000/mm³.
Paroxysmal nocturnal hemoglobinuria (PNH)
Myelodysplastic Syndrome (MDS)
What are the treatment options for aplastic anemia?
Treatment options are different depending on age, severity of the AA and other considerations.
Bone marrow transplants (BMT)
This is the most successful treatment option for aplastic anemia in otherwise healthy children and young adults with matched marrow donors. Improving the success rate and decreasing the complication of BMT depends on finding the best human leukocyte-associated antigens (HLA) match. If the patient has a HLA matched sibling (matched related sibling), bone marrow transplant will be very good option. However, 70 percent of patients do not have matched related donor and must search for unrelated donor, through bone marrow registries.
About 80 percent of transplants conducted with marrow from matched related donors are successful, while transplants with unrelated matched donors are only about half as effective. It is a good idea to explore donor possibilities as soon as AA is diagnosed because it can take time to locate an unrelated donor if no matched sibling is available. The outcome of a bone marrow transplant ranges from 70-90 percent for a matched related donor to 50 percent for a matched unrelated donor. Unrelated donor transplants have an increased risk of graft rejection and of graft-versus-host disease (GVHD), a complication in which the new marrow reacts against the patient.
Immunosuppressive drug therapy
This is considered the standard initial therapy for older patients and for all patients without a matched related donor. The treatment requires brief hospitalization and is well tolerated. Response rates, defined by when the patient is transfusion-independent and free from infections, are 70-80 percent. Patients may need repeating immunosuppressive drug therapy. Also myelodysplastic syndrome and leukemia rates are higher later in life in patients treated with immunosuppressive drugs, 15 to 20 percent according to some studies [[needs to be clarified]]. Antithymocyte globulin (ATG) and cyclosporine are the drugs most frequently used to treat AA.
Growth factors are normal body products that encourage production of blood cells. For example, granulocyte colony-stimulating factor (G-CSF, Neupogen), erythropoietin (Procrit, Aranesp), and granulocyte-macrophage colony-stimulating factor (GM-CSF, Leukine)
This refers to a study conducted to evaluate a possible new treatment or to continue to learn about an existing treatment.