IgA Deficiency

Definition

Selective deficiency of IgA is the most common immune deficiency disorder. Persons with this disorder have low or absent blood levels of a special protein called immunoglobulin A.

Alternative Names

IgA deficiency

Causes, incidence, and risk factors

IgA deficiency is inherited, which means it is passed down through families. It may be inherited as an autosomal dominant or autosomal recessive trait. It is found in approximately 1 in 700 individuals of European origin. It is less common in people of other ethnicities.

See also: Celiac disease - sprue

Symptoms

Most people with selective IgA deficiency have no symptoms.

Some people with this condition have chronic diarrhea caused by intestinal infections. Some have frequent ear, sinus, and lung infections.

Other symptoms include mouth infections and unexplained asthma or bronchiectasis (a disease in which the small air sacs in the lungs become damaged and enlarge).

Signs and tests

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.

Individual infections should be treated with appropriate antibiotics. In some cases, longer courses of antibiotics may be needed to prevent infections from coming back.

Those with selective IgA deficiency, who also have IgG subclass deficiencies, benefit from immunoglobulin (IVIG) treatments given through a vein.

Autoimmune disease treatment is based on the specific problem.

Note: People without any IgA may develop anti-IgA antibodies if given blood products and IVIG. This may lead to allergies or life-threatening anaphylactic shock. These individuals can safely be given IgA-depleted IVIG.

Expectations (prognosis)

Selective IgA deficiency is less harmful than many other immunodeficiency diseases.

Some people with IgA deficiency will recover on their own and begin to produce IgA in larger quantities over a period of years.

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Reviewer Info: Stuart I. Henochowicz, MD, FACP. Associate Clinical Professor of Medicine, Division of Allergy, Immunology, and Rheumatology, Georgetown University Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.; ADAM Health Illustrated Encyclopedia, 05/06/2008

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.