Hemolytic Anemia

Hemolytic anemia is a general term used to describe a condition in which red blood cells, which help carry oxygen from the lungs to the rest of the body, are broken down faster than the bone marrow is able to produce them.

What Causes Hemolytic Anemia?

Hemolytic anemia may be caused by factors that are either part of the red blood cells' essential nature (intrinsic factors) or factors that affect the cells externally (extrinsic).

Intrinsic causes are generally inherited and result in red blood cells that are defective and have a short lifespan after being produced by the bone marrow. Examples of inherited blood conditions that result in hemolytic anemia include:

• Thalassemia
• Sickle cell anemia
• Hereditary spherocytosis
• Glucose-6-phosphate dehydrogenase (G6PD) deficiency

Extrinsic causes of hemolytic anemia result in the destruction of red blood cells that are initially healthy when they are produced by the bone marrow. Some of these extrinsic causes are temporary in nature and others are more chronic or result in recurrent symptoms. The most common extrinsic causes of hemolytic anemia include:

• Hyperactive immune system (autoimmune hemolytic anemia)
• Infections
• Certain medications
• Abnormal blood vessels
• Trapping in the spleen
• Some cancers, including leukemia and lymphoma

How Is Hemolytic Anemia Diagnosed?

The diagnosis of hemolytic anemia is based on medical history, physical examination and specific tests, depending on the cause. Common tests may include blood tests that examine the degree of anemia and red blood cell production by the bone marrow, evaluate the immune system, assess the function of other organs and look for inherited causes of hemolytic anemia. Urine testing is also common.

Rarely, testing of the bone marrow (aspirating the liquid part of the bone marrow and performing a bone marrow biopsy under anesthesia) may be necessary to look for unusual causes of hemolytic anemia.

What Are the Symptoms of Hemolytic Anemia?

The effects of hemolytic anemia vary depending on the child and the cause of the condition. The most common symptoms associated with hemolytic anemia are as follows:

• Pale or yellow skin
• Yellowness of the eyes
• Unusual fatigue or tiredness
• Lightheadedness or dizziness
• Dark or “tea/cola colored” urine

Other signs or symptoms may include:

• Fast heart rate or heart murmur
• Enlarged liver and spleen
• Exercise intolerance
• Fever
• Decrease in urine output

How Is Hemolytic Anemia Treated?

The treatment of hemolytic anemia is determined by the treating physician and varies according to the cause of the condition as well as the severity of anemia. General supportive therapy is often required and specific extrinsic causes may need to be addressed. The most common treatment is blood transfusion to supply more red blood cells for carrying oxygen around in cases of severe anemia or when symptoms related to anemia are present.

When hemolytic anemia is caused by a hyperactive immune system, treatment with steroids, immune globulin (IVIG) or other medications that suppress the immune system may be necessary. Because the spleen is a common site of red blood cell destruction in hemolytic anemia, surgical removal of the spleen may be required in chronic hemolytic anemia associated with longstanding symptoms.