Secondary aplastic anemia is a failure of the bone marrow to make enough blood cells. All blood cell types are affected.
Secondary aplastic anemia is caused by injury to blood stem cells. Normal blood stem cells divide and turn into all blood cell types, mainly white blood cells, red blood cells, and platelets. When blood stem cells are injured, there is a reduction in all blood cell types.
This condition can be caused by:
When the cause is unknown, it is referred to as idiopathic aplastic anemia. In about half of all cases, no cause can be found.
The disease may be acute or chronic.
Tests may include:
It is critical to find out whether secondary aplastic anemia is caused by a medication or exposure. In some cases, removing the exposure can lead to recovery.
Mild cases of aplastic anemia may be treated with supportive care, or may not need treatment. Blood and platelet transfusions will help correct the abnormal blood counts and relieve some symptoms in moderate cases.
Severe aplastic anemia, which causes a very low blood-cell count, is a life-threatening condition. Younger patients with a severe case of the disease will need a bone marrow transplant if a matching donor can be found. Older patients, or those who do not have a matched bone marrow donor, can be treated with medications that suppress the immune system. These medications include anti-thymocyte globulin (ATG), tacrolimus, or cyclosporine.
ATG consists of antibodies made in horses or rabbits against a type of white blood cell in humans called T cells. It is used to suppress the body's immune system. ATG allows the bone marrow to start generating blood cells again, because many causes of aplastic anemia are thought to be due to the body's own T-cells attacking the stem cells.
Other medications to suppress the immune system, such as cyclosporine, tacrolimus, and cyclophosphamide (Cytoxan) also may be used. Corticosteroids and androgens have been used as well.
The condition usually gets worse unless the cause is removed or the disease is treated.
Untreated severe aplastic anemia usually gets worse, eventually leading to death. Mild and moderate forms of the disease can be slower.
Bone marrow transplant has been successful in young patients. It has a long-term survival rate of approximately 80%. Older patients have a survival rate of 40 - 70% after a transplant.
Call your health care provider if:
Secondary aplastic anemia may be an unavoidable consequence of treatments such as chemotherapy. Avoid toxins such as benzene and arsenic, if possible.
Anemia - secondary aplastic; Acquired aplastic anemia