What Causes Aplastic Anemia?

Damage to the bone marrow's stem cells causes aplastic anemia. When stem cells are damaged, they don't grow into healthy blood cells.

The cause of the damage can be acquired or inherited. Acquired aplastic anemia is more common, and sometimes it's only temporary. Aplastic anemia that's inherited is rare.

In more than half of the people who have aplastic anemia, the cause of the disorder is unknown. Some research suggests that stem cell damage may occur because the body's immune system attacks its own cells by mistake.

Acquired Causes

A number of diseases, conditions, and factors can cause aplastic anemia, including:

• Toxins, such as pesticides, arsenic, and benzene
• Radiation and chemotherapy (treatments for cancer)
• Medicines, such as chloramphenicol (an antibiotic rarely used in the United States)
• Infectious diseases, such as hepatitis, Epstein-Barr virus, cytomegalovirus (si-to-MEG-a-lo-VI-rus), parvovirus B19, and HIV
• Autoimmune disorders, such as lupus and rheumatoid arthritis

In some cases, cancer from another part of the body can spread to the bone and cause aplastic anemia.

Inherited Causes

Certain inherited conditions can damage the stem cells and lead to aplastic anemia. Examples include Fanconi anemia, Shwachman-Diamond syndrome, dyskeratosis congenita, and Diamond-Blackfan anemia.