Immune hemolytic anemia Health Article

Definition

Immune hemolytic anemia is a disorder characterized by anemia due to premature destruction of red blood cells by the immune system.

Alternative Names

Anemia - immune hemolytic

Causes, incidence, and risk factors

Immune hemolytic anemia occurs when antibodies form against the body's own red blood cells. The antibodies will destroy the blood cells because these blood cells are recognized as foreign material within the body. The antibodies may be acquired by blood transfusion, pregnancy (if the baby's blood type is different from the mother's), as a complication of another disease, or from a reaction to medications.

If the cause of antibody formation is disease or medication, it is referred to as secondary immune hemolytic anemia. The cause may also be unknown, as in idiopathic autoimmune hemolytic anemia, which accounts for one-half of all immune hemolytic anemias. The disease may start quite rapidly and be very serious, or it may remain mild and not require specific treatment. Risk factors are related to the causes.

Symptoms

• Fatigue
• Pale or yellow skin color
• Shortness of breath
• Rapid heart rate
• Dark urine
• Enlarged spleen

Signs and tests

• Positive direct or indirect Coombs' test
• High bilirubin levels
• High LDH (enzymes whose levels rise as a result of tissue damage)
• Low serum haptoglobin
• Hemoglobin in the urine
• Elevated absolute reticulocyte count
• Low red blood cell count (RBC) and hemoglobin

Treatment

Treatment with the steroid prednisone is the first therapy that is tried. If prednisone does not improve the condition, a splenectomy (removal of the spleen) may be considered. Treatments with drugs that suppress the immune system will be given if the person does not respond to prednisone and splenectomy.

Blood transfusions, if indicated for severe anemia, are given with caution because of the potential that blood may not be compatible and it may precipitate a reaction.

Expectations (prognosis)

In most people, steroids or splenectomy control anemia. In others, partial control of the anemia is usually achieved.

Complications

Death rarely occurs from severe anemia. Overwhelming infection may occur as a complication of treatment with steroids or splenectomy, since these treatments reduce the body's ability to fight infection.

Calling your health care provider

Call your health care provider if unexplained fatigue or chest pain occurs, or if signs of infection are present.

Prevention

Screening for antibodies in donated blood and in the recipient may prevent hemolytic anemia related to blood transfusions.