Aplastic anemia (a-PLAS-tik uh-NEE-me-uh) is a blood disorder in which the body's bone marrow doesn't make enough new blood cells. Bone marrow is a sponge-like tissue inside the bones. It makes stem cells that develop into red blood cells, white blood cells, and platelets (PLATE-lets).
Red blood cells carry oxygen to all parts of your body. They also carry carbon dioxide (a waste product) to your lungs to be exhaled. White blood cells help your body fight infections. Platelets are blood cell fragments that stick together to seal small cuts or breaks on blood vessel walls and stop bleeding.
It's normal for blood cells to die. The lifespan of red blood cells is about 120 days. White blood cells live less than a day. Platelets live about 6 days. As a result, your bone marrow must constantly make new blood cells.
If your bone marrow can't make enough new blood cells, many health problems can occur. These problems include irregular heartbeats called arrhythmias (ah-RITH-me-ahs), an enlarged heart, heart failure, infections, and bleeding. Severe aplastic anemia can even cause death.
Aplastic anemia is a type of anemia. The term "anemia" usually refers to a condition in which your blood has a lower than normal number of red blood cells. Anemia also can occur if your red blood cells don't contain enough hemoglobin (HEE-muh-glow-bin). This iron-rich protein helps carry oxygen to your body.
In people who have aplastic anemia, the body doesn't make enough red blood cells, white blood cells, and platelets. This is because the bone marrow's stem cells are damaged. (Aplastic anemia also is called bone marrow failure.)
Many diseases, conditions, and factors can damage the stem cells. These conditions can be acquired or inherited. "Acquired" means you aren't born with the condition, but you develop it. "Inherited" means your parents passed the gene for the condition to you.
In many people who have aplastic anemia, the cause is unknown
Aplastic anemia is a rare but serious disorder. It can develop suddenly or slowly. The disorder tends to get worse over time, unless its cause is found and treated. Treatments for aplastic anemia include blood transfusions, blood and marrow stem cell transplants, and medicines.
With prompt and proper care, many people who have aplastic anemia can be successfully treated. Blood and marrow stem cell transplants may offer a cure for some people who have aplastic anemia
Red Blood Cells
The most common symptom of a low red blood cell count is fatigue (tiredness). A lack of hemoglobin in the blood causes fatigue. Hemoglobin is an iron-rich protein in red blood cells. It helps carry oxygen to the body.
A low red blood cell count also can cause shortness of breath; dizziness, especially when standing up; headaches; coldness in your hands or feet; pale skin; and chest pain.
If you don't have enough hemoglobin-carrying red blood cells, your heart has to work harder to move the reduced amount of oxygen in your blood. This can lead to arrhythmias (irregular heartbeats), a heart murmur, an enlarged heart, or evenheart failure.
White Blood Cells
White blood cells help fight infections. Signs and symptoms of a low white blood cell count include fevers, frequent infections that can be severe, and flu-like illnesses that linger.
Platelets stick together to seal small cuts or breaks on blood vessel walls and stop bleeding. People who have low platelet counts tend to bruise and bleed easily, and the bleeding may be hard to stop.
Common types of bleeding associated with a low platelet count include nosebleeds, bleeding gums, pinpoint red spots on the skin, and blood in the stool. Women also may have heavy menstrual bleeding.
Other Signs and Symptoms
Aplastic anemia can cause signs and symptoms that aren't directly related to low blood cell counts. Examples include nausea (feeling sick to your stomach) and skin rashes.
Blood transfusions can help keep blood cell counts at acceptable levels. A blood transfusion is a common procedure in which blood is given to you through an intravenous (IV) line in one of your blood vessels.
Transfusions require careful matching of donated blood with the recipient's blood.
Blood transfusions help relieve the symptoms of aplastic anemia, but they're not a permanent treatment.
Medicines To Suppress the Immune System
Research suggests that aplastic anemia may sometimes occur because the body's immune system attacks its own cells by mistake. For this reason, your doctor may prescribe medicines to suppress your immune system.
These medicines allow your bone marrow to start making blood cells again. They also may help you avoid the need for blood transfusions.
Medicines that suppress the immune system don't cure aplastic anemia. However, they can relieve its symptoms and reduce complications. These medicines often are used for people who can't have blood and marrow stem cell transplants or who are waiting for transplants.
Three medicines—often given together—can suppress the body's immune system. They are antithymocyte globulin (ATG), cyclosporine, and methylprednisolone.
It may take a few months to notice the effects of these medicines. Most often, as blood cell counts rise, symptoms lessen. Blood cell counts in people who respond well to these medicines usually don't reach normal levels. However, the blood cell counts often are high enough to allow people to do their normal activities.
People who have aplastic anemia may need long-term treatment with these medicines.
Medicines that suppress the immune system can have side effects. They also may increase the risk of developing leukemia (lu-KE-me-ah) or myelodysplasia (MI-e-lo-dis-PLA-ze-ah; MDS). Leukemia is a cancer of the blood cells. MDS is a condition in which the bone marrow makes too many faulty blood cells.
Blood and Marrow Stem Cell Transplants
A blood and marrow stem cell transplant replaces damaged stem cells with healthy ones from another person (a donor).
During the transplant, which is like a blood transfusion, you get donated stem cells through a tube placed in a vein in your chest. Once the stem cells are in your body, they travel to your bone marrow and begin making new blood cells.
Blood and marrow stem cell transplants may cure aplastic anemia in people who can have this type of treatment. The transplant works best in children and young adults with severe aplastic anemia who are in good health and who have matched donors.
Older people may be less able to handle the treatments needed to prepare the body for the transplant. They're also more likely to have complications after the transplant.
*The above information is from the NIH-National Heart Blood and Lung Institute*