Overview
Autoimmune hemolytic anemia (AIHA) is a rare type of anemia where your body's immune system attacks and destroys its own red blood cells faster than the bone marrow can produce new ones.
Normally, red blood cells live for about 120 days. In AIHA, they may only live for a few days. This destruction leads to a shortage of red blood cells, which carry oxygen to the body, causing fatigue and shortness of breath.
Most people who get AIHA are middle-aged or older. It is rare in children, usually appearing after a viral illness and resolving on its own. In teenagers, it could indicate an underlying health problem.
Types of AIHA
Autoimmune hemolytic anemia is classified in a few different ways:
By Underlying Cause:
- Primary AIHA: Appears by itself with no other underlying condition.
- Secondary AIHA: Affects you because you have another illness.
By Temperature Reaction:
- Warm antibody hemolytic anemia: The immune reaction takes place at or above normal body temperature.
- Cold antibody hemolytic anemia: Red blood cells are destroyed when you’re exposed to cold temperatures.
Symptoms
Many of the symptoms of AIHA are the same as those of other forms of anemia. Common symptoms include:
- Chills
- Fast heartbeat (tachycardia)
- Pale skin that may start to yellow
- Shortness of breath
- Weakness and fatigue
- Chest pain
- Yellow skin or whites of the eyes (jaundice)
- Dark urine
- A feeling of abdominal fullness related to an enlarged spleen
Specific Symptoms for Cold Antibody Hemolytic Anemia:
- Cold hands and feet
- Bluish or reddish color in hands and feet
- Headache
- Digestive problems
- Pain in the back and legs
Causes
AIHA can be caused by an autoimmune disease (like lupus), where the immune system makes antibodies that mistakenly attack your own red blood cells instead of foreign invaders like bacteria and viruses.
Other potential causes include:
- Cancers: Including chronic lymphocytic leukemia and non-Hodgkin's lymphoma.
- Infections: Like Mycoplasma pneumoniae.
- Medications: Such as penicillin, methyldopa (Aldomet), quinine (Qualaquin), and sulfonamides.
- Viruses: Such as Epstein-Barr virus, cytomegalovirus, HIV, and hepatitis.
Diagnosis
If you suspect anemia, your doctor may refer you to a hematologist (a blood specialist). Diagnosis typically involves:
- Medical History: Discussing past illnesses, medications, and symptoms.
- Physical Exam: Checking for an enlarged spleen or other signs.
- Complete Blood Count (CBC): A blood test to measure:
- Red blood cell, white blood cell, and platelet counts.
- Hemoglobin (oxygen-carrying protein) levels.
- Hematocrit (percentage of blood volume made up of red blood cells).
Additional Tests:
If CBC results suggest anemia, further tests may include:
- Reticulocyte count: Measures young red blood cells. A high count means the marrow is working hard to replace destroyed cells.
- Coombs' test: Detects antibodies attacking red blood cells.
- Peripheral smear: Examines red blood cells under a microscope for signs of destruction.
- Bilirubin test: Levels rise when blood cells are destroyed.
- Haptoglobin test: Levels drop when this protein is used up clearing destroyed red cells.
- Cold agglutinin titer: Tests for antibodies active at cold temperatures.
Treatment
Treatment depends on the underlying cause and severity:
- Underlying Condition: If lupus or another disease is the cause, treating that condition comes first.
- Medication Adjustment: If a medication is the cause, stopping it may resolve the anemia.
- Mild Cases: May not require treatment.
Common Treatments:
- Steroids: Doctors usually prescribe steroids like hydrocortisone or prednisone to suppress the immune system. Reviewing rituximab may also be an option.
- Splenectomy: If medications don't work, surgery to remove the spleen (where much cell destruction occurs) may be needed.
- Immunosuppressants: Drugs like azathioprine (Imuran) and cyclophosphamide (Cytoxan) can suppress the immune system.
- Blood Transfusion: May be necessary in severe cases.
