Selective deficiency of IgA

Alternative names:

IgA deficiency

Definition:

The deficiency or absence of immune globulin A, which results in decreased immune function, increased respiratory infections, gastrointestinal infections, and autoimmune diseases.

Causes, incidence, and risk factors:

IgA deficiency may be inherited as either an autosomal dominant or recessive trait. Affected people often have chronic diarrhea from intestinal infections, frequent respiratory infections, and many develop autoimmune disease. Commonly seen autoimmune diseases associated with selective IgA deficiency are rheumatoid arthritis and lupus erythematosus.

Some people with IgA deficiency will "recover" and begin to produce IgA in larger quantities and over a period of years. These people may become asymptomatic (that is, they no longer have symptoms of the disorder). People with a complete absence of IgA may develop allergies or anaphylactic shock if given gamma globulin.