Idiopathic aplastic anemia is a failure of the bone marrow to properly make all types of blood cells.

Idiopathic aplastic anemia is a condition that results from injury to the blood stem cell, a cell that gives rise to other blood cell types after it divides. As a result, there is a reduction in all blood cell types with this type of anemia. This reduction is called pancytopenia. The affected types of blood cells are red cells, white cells, and platelets.

The cause of idiopathic aplastic anemia is unknown, but is thought to be an autoimmune process (the body reacting against its own cells). Causes of other types of aplastic anemia may be chemotherapy, radiation therapy, toxins, drugs, pregnancy, inherited or congenital (present at birth) disorders, or systemic lupus erythematosus. In some cases, aplastic anemia is associated with another blood disorder, paroxysmal nocturnal hemaglobinuria (PNH).

Symptoms arise as the consequence of bone marrow failure and the loss of blood cell production. Low red cell count (anemia) leads to fatigue and weakness. Low white cell count (leukopenia) causes an increased risk of infection. Low platelet count (thrombocytopenia) results in bleeding, especially of mucus membranes and skin.

The disease may be acute or chronic, and may be progressive. Risk factors are unknown.

• Fatigue
• Pallor
• Shortness of breath with exercise
• Rapid heart rate
• Easy bruising
• Nose bleeds
• Bleeding gums
• Prolonged bleeding
• Frequent or severe infections
• Enlarged lymph nodes (rare)

• Low red blood cells count (anemia)
• Low white blood cell count
• Low reticulocyte count (reticulocytes are immature red blood cell)
• Low platelet count
• Bone marrow biopsy shows few blood cells

Mild cases of aplastic anemia are treated with supportive care. Blood transfusions and platelet transfusions help correct the abnormal blood counts and relieve some symptoms. In some cases, no treatment is required and blood counts are monitored on a regular basis.

Severe aplastic anemia, as evidenced by very low blood cell counts, is a life-threatening condition. Bone marrow transplant is indicated for severe disease in younger patients.

For older patients, or for those who do not have a matched bone marrow donor, antithymocyte globulin (ATG) is the alternative treatment. ATG is a horse serum that contains antibodies against human T cells and is used in an attempt to suppress the body's immune system, allowing the bone marrow to resume its blood cell generating function. In severe cases, ATG is often combined with another medicine to suppress the immune system, such as cyclosporine A.

Other medications to suppress the immune system, such as cyclosporine, may be used.

Untreated aplastic anemia is an illness that leads to rapid death. Bone marrow transplant has been successful in young people, with long term survival of 80%. Older people have a survival rate of 40 - 70%.

Severe infections or bleeding may develop as a result of the disorder itself.

Complications of treatment may include graft failure or graft vs. host disease, an autoimmune disease, after bone marrow transplant. Patients can have reactions to ATG.

Call your health care provider or go to the emergency room if bleeding occurs for no reason, or if bleeding is difficult to stop. Call if you notice frequent infections or unusual fatigue.

There is no known prevention for idiopathic aplastic anemia.