What is aplastic anemia?

Aplastic anemia (AA) is a serious disorder in which the bone marrow, the spongy tissue inside the bones, fails to produce new red cells, white cells, and platelets to replenish those that die off naturally. These cells are critical to supplying oxygen and nourishment to other tissues and organs, fighting infection, and in clotting the blood. Since new cells are no longer being produced by the bone marrow, the body is left susceptible to organ failure, bleeding, and infection.

It is a common misconception that aplastic anemia is a cancer, but it’s not. The therapies used to treat it – typically, chemotherapy drugs and bone marrow transplantation – are similar to those used for malignancies like leukemias and lymphomas. Recently, researchers have discovered that most cases of severe aplastic anemia are autoimmune disorders in which the body's own immune system attacks tissues and organs. They believe that abnormal immune cells known as lymphocytes suppress blood cell production and division.

Aplastic anemia has multiple causes, although some cases occur sporadically for no known reason. Other causes are inherited while some are secondary, resulting from a previous illness or disorder. Acquired causes, however, may include the following:

• history of specific infectious diseases such as hepatitis, Epstein-Barr virus (EBV), cytomegalovirus (CMV), parvovirus B19, or human immunodeficiency virus (HIV)
• history of taking certain medications, such as antibiotics and anticonvulsants
• exposure to certain toxins, such as heavy metals
• exposure to radiationhistory of an autoimmune disease, such as lupus.