Definition Aplastic anaemia is a disease of the bone marrow in which there is a failure to generate blood cells.
What is going on in the body? This disease results in an empty bone marrow, instead of a normal bone marrow filled with developing blood cells. It can be inherited or caused by other factors. The bone marrow fills up with fat, resulting in a lack of cell production and low blood counts. Low blood counts can cause life-threatening problems to occur, including severe anaemia, or low blood count, bleeding problems and infections. Aplastic anaemia occurs in both men and women at any age.
What are the signs and symptoms of the disease? Symptoms are related to the low blood cell counts. Anaemia is a decrease in the number of red blood cells, which carry oxygen from the lungs to the rest of the body. Anaemia causes fatigue, pale skin, weakness, fast heart beats or even heart failure. Low platelet counts put people at risk for bleeding, as platelets are involved in blood clotting. Low platelets may result in abnormal bruising, nosebleeds, internal bleeding and even bleeding into the brain. Low white blood cells put people at risk for many different kinds of infection. White blood cells are part of the immune system and help to fight off bacteria and other infection causing particles. Fever, skin boils, sinus infections, pneumonia, kidney infections or other infections may result.
What are the causes and risks of the disease? Causes of aplastic anaemia include:
inherited or genetic causes, which may be present at birth
pregnancy and certain blood disorders can also be rare causes
Often the cause is not known.
What can be done to prevent the disease? Avoiding toxins or excessive chemotherapy drugs can help prevent the disease. Often, the cause is not known and so prevention is not possible. Screening for genetic diseases is becoming more common and reliable.
How is the disease diagnosed? Blood tests are used to show a low number of red cells, platelets, and white blood cells. A bone marrow biopsy is often performed, which usually involves inserting a special needle into the hip bone to obtain a piece of tissue. Fewer bone marrow cells and more bone marrow fat are seen in aplastic anaemia. Tests for other diseases may be needed.
What are the long-term effects of the disease? This disease is life threatening and people die of complications unless successful treatment is given. Some aplastic anaemias are of short duration and resolve quickly. Others are permanent and need extensive treatment.
What are the risks to others? This is not a contagious disease which can be passed on to others.
What are the treatments for the disease? Treatments can help prevent dangerous complications. Red blood cell or platelet transfusions and antibiotics may be used.
Other treatments depend on the cause. There are many treatments available. Some treatments, such as filgrastim or granulocyte-colony stimulating factor (G-CSF), work by stimulating the bone marrow. Other treatments, such as anti-thymocyte globulin (ATG), anti-lymphocyte globulin (ALT), and cyclosporin, work by manipulating the immune system.
Sometimes matched stem cell transfusion or bone marrow transplants are used. These transplants are potentially dangerous and are normally reserved for irreversible cases of aplastic anaemia.
What are the side effects of the treatments? Side effects may include reactions to drugs and transfusion that may cause additional bone marrow damage. Permanent immune system damage can also occur. Infections and other life-threatening side effects are possible. Improvement can be fast or gradual.
What happens after treatment for the disease? Some treatments may be prolonged and include blood and bone marrow testing. Aplastic anaemia that goes away on its own may need no further monitoring.
How is the disease monitored? Monitoring is done with blood and bone marrow tests. Visits to haematologists, geneticists, pathologists, and an adequate blood bank are needed. A return of the disease is rare unless the cause is genetic.
Author: Thomas Fisher, MD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 21/09/2004 Contributors Potential conflict of interest information for reviewers available on request