Autoimmune Hemolytic Anemia

Autoimmune Hemolytic Anemia Definition

Autoimmune hemolytic anemia or AIHA is a rare condition of the blood, wherein an individual produces certain substances that can lead to the damage of red blood cells caused by their own body, resulting to anemia. All blood cells in the body are created in the bone marrow which is the spongy, red part inside the bones.

Blood cells are differentiated into three primary types:

  • Red blood cells – Carries oxygen to the entire body in the form of hemoglobin
  • White blood cells – Fight off infection
  • Platelets – Prevents bleeding

If for any reason the hemoglobin is low, the outcome is anemia. Antibodies are substances being produced by white blood cells, which can identify and neutralize harmful viruses and bacteria. In the case of AIHA; red blood cells are normally produced in the bone marrow, but the main problem is when the body creates an antibody that coats the red blood cells.

When this occurs, these red blood cells will then be recognized as foreign cells and destroyed. If the antibody is damaged, so are the red blood cells. The body will eventually try and make up for this loss through mass production of red blood cells in the bone marrow.

Types

Autoimmune hemolytic anemia can occur in two different types and these are:

  • Warm antibody hemolytic anemia – It is the most common type of AIHA. It is defined as the premature destruction of the healthy red blood cells caused by autoantibodies at above normal body temperature.
  • Cold antibody hemolytic anemia – It is distinguished by the premature destruction of the healthy red blood cells caused by autoantibodies at below normal body temperature.

Symptoms

symptoms of anemia

Symptoms may not occur if autoimmune hemolytic anemia is mild. If symptoms are experienced, they may include:

  • Rapid heart rate
  • Muscle pains
  • Headaches
  • Jaundice
  • Paler color of the skin
  • Nausea
  • Vomiting
  • Diarrhea
  • Weakness or tiredness
  • Abdominal fullness or discomfort
  • Shortness of breath
  • Dark-colored urine

Causes

Most cases of autoimmune hemolytic anemia are idiopathic or occur, without no known cause. Possible causes of the condition may involve:

autoimmune hemolytic anemia types causes

  • Blood transfusion coming from a donor’s blood type that is not compatible
  • Infections
  • Certain toxins, chemicals, and drugs

The antibodies might also be a result of:

  • Pregnancy – if the blood type of the baby is different from the mother’s
  • Complication of an underlying disease
  • Past blood transfusions

Diagnosis

To diagnose AIHA, the physician will first ask the patient some questions and examine the body thoroughly. Several tests may be performed such as:

  • Blood tests – It can supply evidence that the red blood cells have been destroyed. Physicians could count the amount of immature red blood cells in the blood. High amounts indicate that the body has increased its production in an attempt to compensate the blood loss.
  • Urine hemoglobin tests – It could confirm that the red blood cells are being broken down.
  • Direct Coombs test – This checks for increased levels of antibodies that are attached to red blood cells. It is a test particularly designed to diagnose AIHA.

direct indirect coombs test for AIHA acquired hemolytic anemia

  • Test for cold agglutinins – It can assess for high levels of antibodies correlated with infections that may have caused AIHA, such as Mycoplasma pneumoniae which is a type of bacteria that may infect the lungs.

warm and cold autoimmune hemolytic anemia

  • Ultrasound – This may be used to measure the size of the spleen.

The spleen is part of the lymphatic system and is accountable for protecting the body by clearing out red blood cells that are old and have broken down. The spleen is also checked by the physician. If the spleen is enlarged, it can indicate that the body is loaded with an excessive amount of damaged or worn out red blood cells.

Treatment

When autoimmune hemolytic anemia is associated with other diseases, diagnosis and treatment of the underlying health problem can usually lead to a noticeable improvement of the anemia. Patients with mild AIHA may not need any treatment.

On the other hand, those individuals in more severe situations of warm antibody hemolytic anemia might be prescribed to have the intravenous hydrocortisone or oral steroids like prednisone. A patient’s improvement is usually noted within 5 to 10 days after treatment has been given.

Other treatment approaches are taken into consideration in the failure of an effective response to steroid therapy:

  • Total removal of the spleen can be necessary for some resistant cases.
  • Immunosuppressive drugs may be given, like cyclophosphamide or oral azathioprine
  • Blood transfusions might be started to patients identified to have severe cases of   AIHA

Complications

Possible complications of Autoimmune Hemolytic Anemia are:

  • Severe anemia – It rarely results to death
  • Severe infection – It could occur as a complication of certain treatments such as steroids or any other drugs that suppress the immune system. Like certain medications, splenectomy is another treatment that can impair the capacity of the body to fight infection.

References:

http://www.healthline.com/health/immune-hemolytic-anemia#Overview1

http://www.nytimes.com/health/guides/disease/immune-hemolytic-anemia/overview.html#Alternative-Names

Morrison JF, Neufeld EJ, Grace RF (2014 Aug). The use of erythropoietin-stimulating agents versus supportive care in newborns with hereditary spherocytosis: a single centre’s experience. Eur J Haematol. 93(2):161-4.

Ferrer G, Navarro A, Hodgson K, et al (2013 Jan 29). MicroRNA expression in chronic lymphocytic leukemia developing autoimmune hemolytic anemia. Leuk Lymphoma.

Abdulla NE, Ninan MJ, Markowitz AB (2012 Apr 1). Rituximab: current status as therapy for malignant and benign hematologic disorders. BioDrugs. 26(2):71-82.

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