What is Idiopathic Autoimmune Hemolytic Anemia?
Idiopathic autoimmune hemolytic anemia is a type of autoimmune hemolytic anemia (AIHA). AIHA refers to a group of rare but serious blood disorders that occur when the body destroys red blood cells faster than it produces them. A condition is termed idiopathic when its cause is unknown.
Autoimmune diseases attack the body itself. Your immune system produces antibodies to help target foreign invaders such as bacteria and viruses. In the case of autoimmune disorders, your body mistakenly produces antibodies that attack the body itself. In AIHA, your body develops antibodies that destroy red blood cells.
Idiopathic AIHA can be life-threatening because of its sudden onset. It requires immediate medical attention and hospitalization.
Risk Factors for Idiopathic Autoimmune Hemolytic Anemia
About 50 percent of all AIHA cases are idiopathic. AIHA can occur at any point in life and can develop suddenly or gradually. It more commonly affects women.
If AIHA isn’t idiopathic, it’s because it was caused by an underlying disease or medication. However, idiopathic AIHA has no obvious causes. People with idiopathic AIHA may have only abnormal blood test results and no symptoms.
Symptoms of Idiopathic AIHA
You may feel weak and short of breath if you develop sudden-onset idiopathic AIHA. In other instances, the condition is chronic and develops over time, so symptoms are less obvious. In both cases, symptoms may include one or more of the following:
- pale or yellow-colored skin
- muscle pain
- increasing weakness
- shortness of breath
- rapid heartbeat
- dark-colored urine
- a headache
- abdominal discomfort
Diagnosis of Idiopathic AIHA
Your doctor will speak with you extensively about your specific symptoms if they suspect you have AIHA. They’ll need to diagnose you with AIHA and rule out medications or other underlying disorders as the possible causes of the AIHA before diagnosing you with the idiopathic type.
First, your doctor will ask you about your medical history. It’s likely they’ll admit you to the hospital for immediate testing and monitoring if your symptoms are serious. Examples of serious issues include discolored skin or urine or severe anemia. They may refer you to a blood specialist, or a hematologist.
You’ll need to have an extensive series of blood tests to confirm AIHA. Some of the tests will measure the body’s red blood cell count. If you have AIHA, your red blood cell count number will be low. Other tests will look for certain substances in the blood. Blood tests that reveal an incorrect ratio of immature to mature red blood cells may indicate AIHA. A high number of immature red blood cells indicate that the body is trying to compensate for the mature red blood cells that are being destroyed too quickly.
Other blood test findings include a higher-than-normal level of bilirubin and a decreased level of a protein called haptoglobin. Bilirubin is a natural byproduct of red blood cell breakdown. These levels become high when large numbers of red blood cells are destroyed. The haptoglobin blood test can be especially useful in diagnosing AIHA. In conjunction with other blood tests, it reveals that the protein is being destroyed along with mature red blood cells.
In some cases, the typical lab results for these blood tests may not be enough to diagnose AIHA, so your doctor may need to perform more tests. Other tests, including the direct and indirect Coombs tests, can detect increased antibodies in the blood. Urinalysis and a 24-hour urine collection may reveal abnormalities in the urine, such as high levels of protein.
Treatment of Idiopathic AIHA
People suspected of having sudden onset idiopathic AIHA will generally be hospitalized immediately because of its acute nature. Chronic cases may often come and go without explanation. It’s possible for the condition to improve without treatment.
Your doctor will monitor your blood glucose levels closely if you have diabetes. Diabetes is a major risk factor for deaths from infection as a result of treatment.
The first-line treatment is typically steroids such as prednisone. They may help improve red blood cell counts. Your doctor will carefully monitor you to check that the steroids are working. Once your condition goes into remission, your doctor will try to wean you off of the steroids slowly. People with AIHA undergoing steroid therapy may need supplements during treatment. These could include:
- vitamin D
- folic acid
Your doctor may suggest surgical removal of the spleen if the steroids don’t work completely. Removal of the spleen can reverse the destruction of red blood cells. This surgery is known as a splenectomy. Two-thirds of people who undergo a splenectomy have a partial or total remission from their AIHA, and people with the idiopathic type tend to have the most successful results.
Other treatment options are immune-suppressing drugs, such as azathioprine and cyclophosphamide. These can be effective medications for people who don’t successfully respond to treatment with steroids or who aren’t candidates for surgery.
In some cases, the medication rituximab may be preferred over the traditional immune-suppressing drugs. Rituximab is an antibody that directly attacks specific proteins found on certain immune system cells.
Outlook for Idiopathic AIHA
It can be difficult to get a quick diagnosis of this condition in cases where the cause of it is unknown. Treatment is sometimes delayed in these cases. Idiopathic AIHA can be fatal if left untreated.
Idiopathic AIHA in children is typically short-lived. The condition is often chronic in adults, and can flare up or reverse itself without explanation. AIHA is highly treatable in both adults and children. Most people make a full recovery.