MedlinePlus Medical Encyclopedia: Selective deficiency of IgA

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Selective deficiency of IgA

Contents of this page:
Illustrations Alternative names Definition Causes, incidence, and risk factors Symptoms Signs and tests	Treatment Expectations (prognosis) Complications Calling your health care provider Prevention

Illustrations

Antibodies

Alternative names Return to top

IgA deficiency

Definition Return to top

Selective deficiency of IgA is defined as low levels of or complete absence of immune globulin A, which causes decreased immune function in the mucosal surfaces (e.g., mouth, gastrointestinal tract, and lungs) and results in increased risk for respiratory and gastrointestinal infections. It is associated with autoimmune diseases.

Causes, incidence, and risk factors Return to top

IgA deficiency may be inherited as either an autosomal dominant (requiring only one parent to pass down the defective gene) or recessive (requiring defective genes from both) trait and is found in approximately 1 in 700 individuals of European origin. It is less common in people of other ethnicities.

Affected people often have chronic diarrhea caused by intestinal infections, frequent respiratory infections. Many develop autoimmune diseases like rheumatoid arthritis and lupus erythematosus.

Symptoms Return to top

family history of IgA deficiency
family history of agammaglobulinemia (Bruton agammaglobulinemia)
mouth infections
frequent respiratory infections
unexplained asthma and/or bronchiectasis
chronic diarrhea

Signs and tests Return to top

Serum immunoelectrophoresis
Quantitative immunoglobulins (serum IgA extremely low or absent)

Treatment Return to top

No specific treatment is available for IgA deficiency. However, transfusion of IV Ig (intravenous immune globulin) can be harmful. Some people gradually develop normal levels of IgA without treatment. Individual infections should be treated with appropriate antibiotics. Autoimmune disease treatment is based on the specific problem.

Expectations (prognosis) Return to top

Selective IgA deficiency is more benign than many other immunodeficiency diseases.

Some people with IgA deficiency will recover spontaneously and begin to produce IgA in larger quantities over a period of years. People with a complete absence of IgA may develop allergies or anaphylactic shock if given gamma globulin.

Complications Return to top

An autoimmune disorder may also develop. Patients with IgA deficiency may develop antibodies to IgA, and can have severe reactions (including anaphylaxis, a potentially life-threatening allergic reaction) to transfusions of blood and blood products. If transfusions are necessary, they should ideally come from another IgA-deficient individual.

Calling your health care provider Return to top

Consider genetic counseling if there is a family history of selective IgA deficiency and children are planned.

If you have an IgA deficiency, be sure to mention it to the provider if gamma globulin is suggested as a treatment for any condition.

Prevention Return to top

Genetic counseling may be of value to prospective parents with a family history of selective IgA deficiency.

Update Date: 10/30/2003

Updated by: Donald Accetta, MD, MPH. President, Allergy & Asthma Care, PC, Taunton, MA. Review provided by VeriMed Healthcare Network.

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