Aplastic anemia

Overview

Aplastic anemia is a rare and serious condition characterized by the inability of the bone marrow stem cells to produce enough blood cells, which makes the body more susceptible to uncontrolled bleeding and infections. Aplastic anemia is a form of bone marrow failure syndrome.

This condition might happen quickly or gradually and get worse over time. Ideally, the body produces red blood cells, white blood cells, and platelets. With aplastic anemia, it can stop producing one but usually the body will run low on all three. It could be fatal if the blood count falls too low.

Studies have shown that the immune system of the body assaults its own tissues and organs in most cases of severe aplastic anemia. In this severity, a bone marrow transplant may be needed. Medications, blood transfusions or a stem cell transplant are possible treatments for aplastic anemia.

There are two types of aplastic anemia: acquired and inherited. Acquired aplastic anemia is triggered by issues in the immune system, while inherited aplastic anemia is caused by gene defects.

Symptoms

Symptoms may vary according to every person, which may onset gradually or suddenly. Symptoms include:

• Tiredness
• Pale skin
• Difficult breathing
• Irregular or rapid heartbeat
• Frequent or prolonged infections
• Bleeding or bruising easily
• Excessive bleeding of wounds
• Skin rash
• Headache or dizziness
• Fever

Aplastic anemia can develop into a chronic or life-threatening condition. In some cases, it may be temporary.

Causes

Red blood cells, white blood cells, and platelets are created by stem cells in the bone marrow. Each of the blood cells plays a different role. The red blood cells transport oxygen throughout the body. The white blood cells fight infection. The platelets prevent bleeding. When the stem cells are compromised, it can result to the bone marrow being aplastic (empty) or hypoplastic (small number of blood cells).

Issues with the immune system, specifically destroying the stem cells in the bone marrow is the most common cause of aplastic anemia. Other factors that can harm bone marrow and influence the production of blood cells include:

• Radiation and chemotherapy: These medical treatments are powerful tool to treat cancer. It uses medications and high-powered X-rays to destroy cancer cells and stop tumor growth. However, it can also harm healthy cells, including bone marrow stem cells. The aplastic anemia associated with this is usually temporary.
• Toxic chemicals exposure: Exposure to harmful substance can trigger and cause aplastic anemia. Toxic substances include those from herbicides, insecticides and benzene, a component of gasoline.
• Drug: Aplastic anemia can be caused by several certain drugs, including certain antibiotics and rheumatoid arthritis medicines.
• Autoimmune disorders: Stem cells in the bone marrow may be affected by an autoimmune disease such as eosinophilic fasciitis or lupus. The immune system attacks healthy cells which result to aplastic anemia.
• Pregnancy: Aplastic anemia may manifest during pregnancy if the immune system attacks the bone marrow.
• Viral infection: Aplastic anemia has been associated with the hepatitis, Epstein-Barr, CMV, parvovirus B19, and HIV viruses. These viral infections can affect the bone marrow and cause aplastic anemia.
• Idiopathic aplastic anemia: The underlying cause is unknown.

Connections with other rare disorders

There are other blood disorders that may be experienced by those with aplastic anemia such as, Fanconi’s anemia and Paroxysmal nocturnal hemoglobinuria.

Fanconi’s anemia (FA) is a genetic disorder that can cause aplastic anemia. It can also result in physical anomalies that may change a person’s appearance such as underdeveloped limbs.

Paroxysmal nocturnal hemoglobinuria is a rare condition which causes red blood cells to break down prematurely. Aplastic anemia may result from this disorder, or aplastic anemia itself may develop into paroxysmal nocturnal hemoglobinuria.

Risk factors

Aplastic anemia is rare although it may affect anyone. A person becomes more susceptible to it due to these factors:

• Cancer treatment such as radiation and chemotherapy
• Toxic substance exposure
• Prescription medications such as gold compounds for rheumatoid arthritis and chloramphenicol for bacterial infections treatment
• Autoimmune diseases and severe infection
• Pregnancy (rare)
• Other blood disorders

Statistics shows that aplastic anemia are commonly diagnosed on Asian or Asian-American, teenager or young adult, and those aged 65 years and older.