What is Selective Immunoglobulin A Deficiency?

Selective immunoglobulin A deficiency means that you either do not have any or do not have enough immunoglobulin A (IgA). IgA is found in your blood and in other areas of the body, such as your lungs, sinuses, digestive tract, and skin.

IgA is a type of protein that your body needs to fight off infections (antibody). There are four other types of antibodies: IgE, IgD, IgM, and IgG. Selective IgA deficiency is the most common type of antibody deficiency. It can occur at any age.

What are the causes?

Usually, the cause of this condition is not known. However, possible causes include:

• A genetic defect (mutation) passed down through families.
• Viral infections, such as rubella and cytomegalovirus.
• Certain medicines, including aspirin, ibuprofen, and drugs used to treat arthritis, high blood pressure, seizures, thyroid disease, and malaria.

What increases the risk?

This condition is more likely to develop in:

• People who are taking a medicine that can cause IgA deficiency.
• People who have a family history of IgA deficiency.

What are the signs or symptoms?

This condition on its own may not cause any symptoms. However, this condition can cause you to get more frequent or long-lasting (chronic) infections, such as:

• Pneumonia.
• Upper respiratory infections.
• Ear infections.
• Sinusitis.
• Eye infections.
• Skin infections.

This condition can also make you more likely to:

• Develop a disease in which your body’s defense system (immune system) attacks the normal tissues of your body (autoimmune disease). This causes inflammation. Autoimmune diseases may also cause swollen joints, skin rash, diarrhea, and belly pain.
• Have allergies. An allergy may cause nasal congestion, nasal polyps, and asthma.
• Have a type of very severe allergic reaction (anaphylaxis) if you get a blood transfusion that contains IgA antibodies or if you are given a transfusion of antibodies (immune globulins). This is rare. If it does occur, it may cause swelling, difficulty breathing, and very low blood pressure.
• Develop chronic gastrointestinal conditions, such as inflammatory bowel disease.

How is this diagnosed?

This condition is diagnosed based on your symptoms, your medical history, and a physical exam. You may also have a blood test to confirm the diagnosis. Other blood tests may be done to measure the levels of your other antibodies or to look for signs of infection. You may also have imaging studies of your lungs or sinuses.

How is this treated?

Treatment may include:

• Taking antibiotic medicines to fight or prevent infections.
• Stopping the use of any medicines that might be causing IgA deficiency.
• Treating your allergies.
• Treating an autoimmune disease that you may develop.

If your condition is not causing any other diseases, allergies, or infections to develop, you may not need treatment.

Follow these instructions at home:

• Take over-the-counter and prescription medicines only as told by your health care provider.
• Wear a medical ID bracelet to alert health care providers about the possibility of an anaphylactic reaction from a transfusion.
• Ask your health care provider if you should follow a diet for related gastrointestinal symptoms or conditions.
• Do not drink water from a source that may be unclean. Unclean water can cause an infection.
• Do not use any tobacco products, such as cigarettes, chewing tobacco, and e-cigarettes. If you need help quitting, ask your health care provider.

Contact a health care provider if:

• You have a fever.
• You have congestion that is getting worse.
• You develop a cough or sore throat.
• You have diarrhea.

Get help right away if:

• You have hives.
• You have wheezing or shortness of breath.