The blood that circulates throughout the body performs a number of critical functions. It delivers oxygen, removes carbon dioxide, and carries life-sustaining nutrients. By acting as the vehicle for long-distance messengers such as hormones, blood helps the various parts of the body communicate with each other. This is carried out by blood cells working in partnership with the liquid part of the blood (plasma).
Most of the cells that make up your blood are red blood cells (RBCs; erythrocytes). Also present are white blood cells (WBCs; leukocytes), which defend the body against foreign matter, including infections, viruses, and fungi.
Anemia is a condition where the number of healthy RBCs in the blood is lower than normal. RBCs transport oxygen throughout the body, so a shortage of these cells can lead to serious health problems.
In aplastic anemia, the bone marrow drastically cuts down on its production of all types of blood cells (red, white, and platelets). Aplastic actually means "a failure in development." Aplastic anemia, acute or chronic, is a rare and serious condition that can occur spontaneously or be triggered by exposure to certain medications or toxins.
Dr. Paul Ehrlich, a famous German pathologist, first identified the condition in 1888 after studying the case of a pregnant woman who died of bone marrow failure. In 1904, the disorder was termed aplastic anemia.
Aplastic anemia isn't restricted to any age or gender. There are 2 to 12 new cases for every million people each year. The Aplastic Anemia & MDS International Foundation has a voluntary patient registry to track statistics on people with these conditions.
A very rare form of aplastic anemia, Fanconi anemia (a type of hereditary aplastic anemia with bone abnormalities and brown pigmentation in the skin), occurs in some children with abnormal chromosomes.
Most of the causes of aplastic anemia are unknown. Certain cancer treatments, such as high doses of chemotherapy or radiation treatment, can cause aplastic anemia. Other possible causes include chemicals (such as benzene-based compounds), various over-the-counter and prescription medications (such as sulfonamides, nifedipine, anti-epileptic medications including phenytoin, valproic acid, carbamazepine), viruses (such as the parvovirus B19), immune diseases (such as hepatitis or HIV), pregnancy, street drugs, and environmental toxins (such as insecticides and pesticides). Fanconi anemia is an inherited condition.
Symptoms and Complications
Symptoms of aplastic anemia occur because of the low blood cell counts. Because of fewer RBCs present, people may have pale skin and feel tired, weak, or short of breath. The low platelet count may cause bruising and bleeding to easily occur. And people with aplastic anemia may be more likely to get bacterial infections because of the low number of WBCs, which fight infection. Cases of infection and hemorrhaging (excessive bleeding) are emergencies and must be treated quickly.
Other symptoms may include a waxy pallor to the skin and mucous membranes, bleeding gums, a lack of energy during exercise, and tinnitus (ringing in the ears). Premenopausal women may have an increased menstrual flow and duration. Massive bleeding is unusual.
Making the Diagnosis
To diagnose aplastic anemia, your doctor will conduct a complete physical exam to check for paleness, bruising, oozing gums, and other unusual signs. They will order blood tests to get a complete blood cell count and will probably also arrange for a sample of your bone marrow so it can be checked for abnormalities.
Treatment and Prevention
The first and most important step of treatment is to find out and treat the cause of the aplastic anemia. People with aplastic anemia must do everything they can to avoid getting infections. If any develop, the infections are treated aggressively with antibiotics. Transfusions of red blood cells (RBCs) and platelets may be considered.
Treatment of aplastic anemia involves a combination of removing agents that may cause aplastic anemia, providing supportive care (through transfusions and antibiotics), and delivering treatment for aplastic anemia (i.e., hematopoietic cell transplantation or immunosuppressive therapy).
Hematopoietic cell transplantation (HCT) can potentially cure aplastic anemia. It involves the transplant of healthy bone marrow stem cells from a compatible donor (most often a matched sibling donor). This treatment is only recommended for younger patients under 20 years old or for healthy patients between the ages of 20 to 50 years. HCT is not recommended for those with relapsing or resistant aplastic anemia.
Immunosuppressive therapy is used to treat aplastic anemia when it is caused by an autoimmune disorder (a condition where the body is attacking its own bone marrow). Bone marrow transplantation, which replaces defective bone marrow with healthy cells from a normal donor, may be recommended in severe cases.
Blood transfusions are used to replace the blood cells that are not being produced by the bone marrow the way they should be. Transfusions can replace RBCs and platelets, but white blood cells (WBCs) are harder to transfuse. People with aplastic anemia can receive blood transfusions for many years, but there are some complications that can develop from this treatment. RBC transfusions contain iron that builds up in the body and can damage normal tissues. Proteins on the transfused blood cells stimulate the immune system, and over time antibodies may be produced that destroy the transfused RBCs or platelets.
Also, blood from transfusions may contain viruses or other infections that may be passed on to the recipient. The blood supply today, however, is safer than ever because it's tested for major infections before being used for transfusions.
Growth factor medications are also used. These medications stimulate blood production (e.g., erythropoietin). Herbal treatments and vitamins aren't effective treatments for aplastic anemia, and can in fact make the condition worse and interfere with treatment. They should be taken only under a doctor's supervision. It is very important to have proper nutrition as this will help the body produce blood.
Because aplastic anemia can be life-threatening, quick diagnosis and treatment is crucial. Most people with the disorder can be effectively treated.
The long-term outlook for those who respond to therapy is unknown. As with any serious and chronic condition, there are many emotional side effects that people with aplastic anemia and their families may experience due to the stress of the illness and medical treatments. It's extremely important to get adequate psychosocial support such as from patient support groups, associations, and volunteers, to help cope. Today, people with aplastic anemia and their families can share their experiences with others around the world using the Internet.