Selective deficiency of IgA is the most common immune deficiency disorder. People with this disorder have a low or absent level of a blood protein called immunoglobulin A.
IgA deficiency is usually inherited, which means it is passed down through families. However, cases of drug-induced IgA deficiency have been reported.
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.
Many people with selective IgA deficiency have no symptoms.
If a person does have symptoms, they may include frequent episodes of:
Other symptoms include:
There may be a family history of IgA deficiency. Tests that may be done include:
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.
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.
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.
If you have an IgA deficiency, be sure to mention it to your health care provider if immunoglobulin or other blood-component transfusions are suggested as a treatment for any condition.
Genetic counseling may be of value to prospective parents with a family history of selective IgA deficiency.
Reviewed By: Stuart I. Henochowicz, MD, FACP, Associate Clinical Professor of Medicine, Division of Allergy, Immunology, and Rheumatology, Georgetown University Medical School, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.