immunoglobulin A


Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia, Wikipedia.

immunoglobulin A

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.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

immunoglobulin A

Abbreviation: 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
Medical Dictionary, © 2009 Farlex and Partners