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n. Abbr. IgA
The class of antibodies produced predominantly against ingested antigens, found in body secretions such as saliva, sweat, or tears, and functioning to prevent attachment of viruses and bacteria to epithelial surfaces.
immunoglobulin A (IgA)
one of the most prevalent of the five classes of antibodies produced by the body. It is found in all secretions of the body and is the major antibody in the tears, saliva, and mucous membranes lining the intestines and bronchi. IgA combines with a protein in the mucosa and defends body surfaces by seeking out foreign microorganisms and triggering an antigen-antibody reaction. The normal concentration of IgA in serum is 50 to 250 mg/dL. Compare immunoglobulin D, immunoglobulin E, immunoglobulin G, immunoglobulin M. See also IgA deficiency.
immunoglobulin AAbbreviation: IgA
The principal immunoglobulin in exocrine secretions such as milk, respiratory and intestinal mucin, saliva, and tears. It prevents pathogenic bacteria and viruses from invading the body through the mucosa of the gastrointestinal, pulmonary, and genitourinary tracts. Its presence in colostrum and breast milk helps prevent infection in breast-feeding infants.
See also: immunoglobulin
immunoglobulin A (IgA) (imˈ·my·nō·glˑ·by·lin āˑ),
n protein located in body fluids that guards against infection in mucosal surfaces.