What Is Autoimmune Hemolytic Anemia?

Blood work
Blood work. TEK IMAGE/Science Photo Library/Getty Images


Autoimmune hemolytic anemia (AIHA) is an acquired condition where the immune system attacks and destroys the red blood cells leading to anemia which can be severe.  

What Are the Symptoms of AIHA?

Symptoms can vary and are related to the severity of anemia. 

  • Fatigue or tiredness
  • Pallor
  • Yellowing of the skin (jaundice) or eyes ( scleral icterus)
  • Enlarged spleen (splenomegaly)
  • Palpitations or rapid heart beat
  • Dark urine

Who Is at Risk?

AIHA can happen in any age group from childhood into adulthood.  Women are at a higher risk as they are at greater risk of autoimmune disorders in general.  

What Causes AIHA?

Sometimes we cannot figure out what triggered the AIHA.  This is called idiopathic AIHA.  

Other causes include:  

  • Infections, particularly Epstein Barr Virus (EBV, the cause of mono) and mycoplasma
  • Cancer particularly lymphomas
  • Other autoimmune diseases like lupus, rheumatoid
  • Medications:  antibiotics (cephalosporins, penicillin, tetracycline), interferon alfa, ibuprofen, and others

How Is AIHA Diagnosed?

This depends on the severity of the anemia.  The anemia is identified on complete blood count.  The reticulocyte count (immature red blood cells) will be elevated as the bone marrow attempts to correct the anemia with new red blood cells.  

Other tests may be sent to confirm that the anemia is secondary to hemolysis (breakdown of red blood cells) such as bilirubin and lactate dehydrogenase.


For most cases of AIHA, direct antiglobulin testing (DAT, also called a direct Coombs) confirms the diagnosis.  This testing looks for the presence of red blood cell antibodies. 

Are There Different Types of AIHA?

Yes, there are 3 types of AIHA.  

Warm AIHA:  This is the most common form of AIHA, particularly in children.

 Warm refers to the fact that the red blood cell antibodies attach to the red blood cell at warm temperatures (body temperature).

Cold Agglutinin Disease (CAD):   This is basically the opposite of warm AIHA.  In cold agglutinin disease, the antibodies attach to the red blood cells at cold temperatures (32-50F).  This caused the red blood cells to stick to one another (agglutination) which are then destroyed.  The amount of hemolysis increases when you are exposed to cold.  This is extremely rare in children.  

Paroxysmal Cold Hemoglobinuria (PCH):  Similar to CAD, antibodies bind to the red blood cells when exposed to cold temperatures (mostly hands and feet), as the red blood cells return to the heart and get warmer, these antibodies destroy the red blood cell.  Hemoglobinuria is the term for hemoglobin in the urine.  As red blood cells are destroyed, hemoglobin is released and passes into the urine.  This is the rarest type of AIHA.

What Are the Treatment Options?  

Transfusions:  Transfusions can be very difficult.

The antibodies in AIHA don't care if the red blood cells belong to you or someone else, they attack them all.  They are reserved for severe cases with symptoms of anemia. The hope is that at least temporarily your red blood cell count will come up while other treatments have time to work.  If you have CAD or PCH, the blood should be warmed prior to infusion.  

The following treatments are predominantly used for warm AIHA.  

Steroids:  Steroids, like methylprednisolone or prednisone, are the mainstay of therapy for warm AIHA.   Steroids reduce the destruction of red blood cells in the spleen. 

Splenectomy:  The red blood cells are destroyed in the spleen so removal of the spleen may result in increased survival of red blood cells.  

Rituximab:  This medication helps to destroy the white blood cells that produce the antibodies against red blood cells, called B-cells.  The hope is that when your B-cells regenerate, they will no longer make the antibody. 

The primary treatment of CAD and PCH is supportive care and cold avoidance.  Steroids are sometimes used with limited success.  Because the antibodies attached the red blood cells when exposed to cold, avoiding cold temperatures is very important for patients with CAD and PCH.  This includes bundling up even in the summer with scarves, gloves, and boots.  Also patients should avoid ice and cold beverages. 

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