Selective IgA deficiency

Other Names: IGAD1; Immunoglobulin A, selective deficiency of; IgA, selective deficiency of; Gamma-A-globulin, selective deficiency of; Immunoglobulin A deficiency 1

Selective IgA deficiency is the most common type of primary immunodeficiency syndrome. Individuals with this condition have a complete absence or severe deficiency of IgA, which is essential in the respiratory and gastrointestinal tracts and plays a role in developing mucosal immunity and protection against infection. While many people with selective IgA deficiency appear healthy, they are more prone to infections, allergies, diarrhea, and autoimmune diseases.

Cause

The underlying cause of selective IgA deficiency is unknown.

Inheritance

It may be inherited as an autosomal dominant or autosomal recessive trait. It is usually found in people of European origin. It is less common in people of other ethnicities.

Signs and symptoms

Many people with selective IgA deficiency have no symptoms.

If a person does have symptoms, they may include frequent episodes of:

• Bronchitis (airway infection)
• Chronic diarrhea
• Conjunctivitis (eye infection)
• Gastrointestinal inflammation, including ulcerative colitis, Crohn disease, and a sprue-like illness
• Mouth infection
• Otitis media (middle ear infection)
• Pneumonia (lung infection)
• Sinusitis (sinus infection)
• Skin infections
• Upper respiratory tract infections

Other symptoms include:

• Bronchiectasis (a disease in which the small air sacs in the lungs become damaged and enlarged)
• Asthma without a known cause

Diagnosis

There may be a family history of IgA deficiency. Tests that may be done include:

• IgG subclass measurements
• Quantitative immunoglobulins
• Serum immunoelectrophoresis

Treatment

No specific treatment is available. Some people gradually develop normal levels of IgA without treatment. Treatment involves taking steps to reduce the number and severity of infections. Antibiotics are often needed to treat bacterial infections. Immunoglobulins are given through a vein or by injection to boost the immune system. Autoimmune disease treatment is based on the specific problem.

Note: People with complete IgA deficiency may develop anti-IgA antibodies if given blood products and immunoglobulins. This may lead to allergies or life-threatening anaphylactic shock. However, they can safely be given IgA-depleted immunoglobulins.

Prognosis

Selective IgA deficiency is less harmful than many other immunodeficiency diseases. Some people with IgA deficiency will recover on their own and produce IgA in larger quantities over a period of years.

Possible Complications Autoimmune disorders such as rheumatoid arthritis, systemic lupus erythematosus, and celiac sprue may develop. People with IgA deficiency may develop antibodies to IgA. As a result, they can have severe, even life-threatening reactions to transfusions of blood and blood products.

NIH genetic and rare disease info

• NIH info on Selective IgA deficiency

Selective IgA deficiency is a rare disease.

Selective IgA deficiency Resources
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