Autoimmune hemolytic anemia

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at December 29, 2016
StartDiseasesAutoimmune hemolytic anemia

Blood is made of red blood cells, white blood cells, and plasma. Red blood cells provide oxygen to the entire body. If a person lacks a sufficient amount of red blood cells, he or she can develop anemia. Autoimmune hemolytic anemia is anemia that is caused by a malfunctioning immune system.

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Definition & Facts

Anemia occurs when the body does not have enough red blood cells or hemoglobin, and it is divided into separate disorders based on the underlying cause of the anemia. Sometimes, anemia can result from an immune response and is considered autoimmune hemolytic anemia.

In this condition, instead of attacking germs, the immune system's antibodies start attacking healthy red blood cells. This type of anemia is very rare, and it more commonly affects women than men.

Autoimmune hemolytic anemia can be further divided into a cold and a warm category. In the warm antibody hemolytic anemia, red blood cells at temperatures above 37 degrees Celsius can be destroyed by antibodies. In patients with cold antibody hemolytic anemia, only blood cells that are at or below normal body temperature are damaged. 

Symptoms & Complaints

General symptoms of autoimmune hemolytic anemia tend to be very mild at first and then gradually worsen. Most symptoms are caused by a lack of oxygen in certain parts of the body. People tend to feel tired and weak all the time.

They may frequently get headaches or chest pains. The ends of limbs are particularly likely to lack blood cells, so people with anemia complain of cold hands and feet. This symptom is especially common in patients with the cold autoimmune hemolytic anemia version.

Anemia can also cause people to feel dizzy, especially when standing suddenly, and they may experience shortness of breath or have an irregular heart rhythm. Skin may look pale, yellowish, or bluish. Yellowed skin can be due to jaundice, or it may just be the underlying color of the skin when not enough blood cells are present.

Extended bouts of autoimmune hemolytic anemia can cause the spleen to enlarge (splenomegaly), resulting in sensations of fullness and a swollen belly. People who have cold antibody hemolytic anemia may notice that their symptoms get worse after frequent exposure to cold.

Causes

All of the symptoms of autoimmune hemolytic anemia occur because the immune system is attacking red blood cells instead of destroying germs. There are many different underlying causes for autoimmune hemolytic anemia. It is associated with autoimmune diseases like lupus or Donath-Landsteiner syndrome.

Certain infections can also lead to this condition. A viral infection like measles, the flu, or chickenpox, or a bacterial infection like syphilis can confuse the immune system and trigger it to start attacking healthy cells. Certain medications, including penicillin, quinine, and sulfonamides can further increase the likelihood of a person developing autoimmune hemolytic anemia.

The immune system may begin attacking otherwise healthy blood cells if they appear even slightly abnormal. Having a deficiency in enzymes like pyruvate kinase or glucose 6 phosphate dehydrogenase can prevent the immune system from recognizing blood cells. Though the enzyme-deficient blood cells still function, the immune system mistakenly views them as a germ or very diseased cell that must be destroyed.

Other blood cell abnormalities like sickle-cell shaped blood cells (sickle-cell disease) or sphere-shaped blood cells (spherocytosis) can also trigger this immune response. Enzyme deficiencies and unusually shaped cells may be inherited from parents.

Diagnosis & Tests

Autoimmune hemolytic anemia can be diagnosed through a combination of a physical examination, a patient's medical history, and two simple blood tests. A doctor may suspect that a patient has anemia if they report classic symptoms of anemia without any other underlying health issues.

Anemia can be tested by examining a blood sample in a laboratory. If a patient does not have adequate ratios of red blood cells in their blood, they are diagnosed with anemia.

The doctor will then try to determine the cause of the anemia. If a patient has normal iron levels and B vitamin levels, then they may suspect that autoimmune hemolytic anemia is the cause of the low red blood cell count.

This diagnosis can be confirmed with a Coombs test. A Coombs test is a type of blood test that looks at a blood sample to see if antibodies are binding to the red blood cells. This is a sign that the red blood cells are being attacked by the immune system, so autoimmune hemolytic anemia is confirmed.

Treatment & Therapy

Different treatments will be recommended depending on a patient's symptoms. In very mild cases, no treatment may be required. Patients with the cold version of the disease may need to avoid chilly temperatures. However, a doctor may prescribe prednisone or another corticosteroid to halt the immune system response and slow red blood cell destruction.

If the autoimmune hemolytic anemia was caused by a medication, an IV with immune globulin can help to decrease the destruction. Basic blood transfusions can also help to treat anemia symptoms, but they will not cure it. Sometimes, autoimmune hemolytic anemia will go away on its own or stop happening after corticosteroid treatments.

If destruction rates are low enough, a patient can live normally with a mild case of autoimmune hemolytic anemia. In rare cases, neither of these treatment plans prove effective, and the red blood cell destruction is severe enough to be problematic. If this happens, a patient may benefit from having their spleen removed because the spleen is the organ that destroys antibody-coated red blood cells.

Prevention & Prophylaxis

Since this condition can arise due to an infection, the best preventative method for autoimmune hemolytic anemia is to avoid getting sick.

People should practice proper hygiene such as regularly washing hands, practice safe sex, consume a healthy diet, and avoid contact with sick people.

Prospective parents who have a genetic susceptibility towards autoimmune hemolytic anemia may benefit from genetic counseling to understand the risk of passing it on to future children.