What is aplastic anemia?
Aplastic anemia (AA) is a rare disease in which the body fails to produce enough blood cells. Stem cells in the bone marrow produce all blood-forming cells, including red blood cells that carry oxygen throughout the body, white blood cells that fight infection and platelets that help blood clot. Aplastic anemia is caused by destruction of these cells.
What causes aplastic anemia?
Most researchers suggest that this stem cell destruction occurs when the body’s immune system attacks its own cells by mistake. It can also be caused by heredity, immune disease or exposure to chemicals, drugs or radiation. In about 50% of cases, however, the cause is unknown.
AA can be acquired or heredity:
- Acquired aplastic anemia can begin anytime in life, but it is more often seen in children and adolescents. Most cases are considered idiopathic, which means they have no known cause. Some cases of acquired aplastic anemia may be caused by radiation and chemotherapy from prior treatments for other diseases. Acquired AA has also been linked with viral infections, including hepatitis B or C, Epstein-Barr, HIV or parvo virus.
- Hereditary AA can be passed down through the genes from a parent to a child, or can be caused by a new gene mutation present from birth. It is usually diagnosed in childhood and is less common than acquired AA. People who develop hereditary AA often, but not always, have other physical abnormalities. Some inherited conditions, also called bone marrow failure syndromes, increase the likelihood that a person will develop the hereditary form of AA.
AA is divided into three categories based on blood cell counts: moderate, severe or very severe.
What are the signs and symptoms of aplastic anemia?
The symptoms of AA are caused by low blood cell counts and include:
- Anemia, which may lead to tiredness, pale skin, headaches and fast heart rate
- Shortness of breath
- Weight loss
- Increase in bruises with an unknown cause
- Spontaneous nose bleeds that are difficult to stop
- Bleeding under the skin, causing tiny, flat red spots (called petechiae) which most often occur on the trunk and lower legs
How is aplastic anemia diagnosed?
Many tests and tools are used to diagnose AA. These help to confirm the diagnosis, look for its cause and find out how severe it is. They are also used to role out other conditions that may cause similar symptoms. Your doctor will start with a medical history, physical examination, and blood tests, including PNH clones and genetic testing. Once all the information has been gathered, your child’s doctor may perform a bone marrow aspirate and biopsy for confirmation and determine any additional abnormalities.
What is the treatment for aplastic anemia?
Treating immune mediated AA involves suppression of the immune system, an effect achieved by daily medicine intake and/or a bone marrow transplant in more severe cases. In patients with an HLA (human leukocyte antigens) matched sibling donor, bone marrow transplant is the first line of treatment. Patients lacking a matched sibling donor typically pursue immunosuppression therapy as a first line of treatment; matched unrelated donor transplants are considered a second line of therapy.
Additional supportive treatment of AA may include:
- Red blood cell transfusions
- Platelet transfusions
- Medication to increase the production of white blood cells