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Immune hemolytic anemia
Definition
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to the body's tissues.
Normally, red blood cells last for about 120 days before the body gets rid of them. In hemolytic anemia, red blood cells in the blood are destroyed earlier than normal.
Immune hemolytic anemia occurs when antibodies form against the body's own red blood cells and destroy them, because the immune system mistakenly recognizes these blood cells as foreign.
Alternative Names
Anemia - immune hemolytic; Autoimmune hemolytic anemia (AIHA)
Causes
Possible causes include:
- Certain chemicals, drugs, and toxins
- Infections
- Transfusion of blood from a donor with a blood type that does not match
When antibodies form against red blood cells for no reason, it is called idiopathic autoimmune hemolytic anemia.
The antibodies may also be caused by:
- Complication of another disease
- Past blood transfusions
- Pregnancy (if the baby's blood type is different from the mother's)
Risk factors are related to the causes.
Symptoms
You may not have symptoms if the anemia is mild. If the problem develops slowly, symptoms that may occur first include:
- Feeling grumpy
- Feeling weak or tired more often than usual, or with exercise
- Headaches
- Problems concentrating or thinking
If the anemia gets worse, symptoms may include:
- Blue color to the whites of the eyes
- Brittle nails
- Light-headedness when you stand up
- Pale skin color (pallor)
- Shortness of breath
- Sore tongue
Exams and Tests
- Absolute reticulocyte count
- Direct or indirect Coombs' test
- Hemoglobin in the urine
- LDH (level of this enzyme rises as a result of tissue damage)
- Red blood cell count (RBC), hemoglobin, and hematocrit
- Serum bilirubin levels
- Serum free hemoglobin
- Serum haptoglobin
Treatment
The first treatment tried is usually a steroid medication, such as prednisone. If steroid medications do not improve the condition, treatment with intravenous immunoglobulin (IVIG) or removal of the spleen (splenectomy) may be considered.
You may receive treatment to suppress your immune system if you do not respond to steroids and splenectomy. Medications such as azathioprine (Imuran), cyclophosphamide (Cytoxan), and rituximab (Rituxan) have been used.
Blood transfusions are given with caution, because the blood may not be compatible and it may cause more red blood cell destruction.
Outlook (Prognosis)
The disease may start quickly and be very serious, or it may remain mild and not need specific treatment.
In most people, steroids or splenectomy can control anemia. In others, treatment can usually partially control the anemia.
Possible Complications
Severe anemia rarely leads to death. Severe infection may occur as a complication of treatment with steroids, other medications that suppress the immune system, or splenectomy, because these treatments impair the body's ability to fight infection.
When to Contact a Medical Professional
Call your health care provider if you have unexplained fatigue or chest pain, or signs of infection.
Prevention
Screening for antibodies in donated blood and in the recipient may prevent hemolytic anemia related to blood transfusions.
References
Schwartz RS. Autoimmune and intravascular hemolytic anemias. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011: chap 163.
Powers A, Silberstein LE. Autoimmune hemolytic anemia. In: Hoffman R, Benz Ej, Shattil SS, et al, eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 47.
Reviewed By: Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.
