title: Bacterium-induced cleavage of IgA in nasopharyngeal secretions from atopic children.
abstract: Immunoglobulin A forms the specific immune barrier of mucosal surfaces against microorganisms and potential allergens. Immunochemical studies of nasopharyngeal secretions (NPS) from 97 children showed enzymatic degradation of IgA in 18.6% of the samples. The observed fragments are characteristically released from IgA by the activity of specific IgA 1 proteases produced by certain bacterial species. A significantly higher prevalence (P less than 0.001) of IgA cleavage was observed in NPS from children with atopic diseases (61.5%) than in controls (11.9%). These results indicate that bacterium-induced local defects in the mucosal immune barrier of the upper respiratory tract may be a factor in the pathogenesis of some forms of atopic disease.
mesh_terms: D001424:Bacterial Infections / Q000150:complications*; D002675:Child, Preschool; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000150:complications / Q000276:immunology*; D007070:Immunoglobulin A / Q000378:metabolism*; D007141:Immunoglobulin Fc Fragments / Q000032:analysis; D009305:Nasopharynx / Q000276:immunology / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D012697:Serine Endopeptidases
chemical_list: D007070:Immunoglobulin A; D007141:Immunoglobulin Fc Fragments; D010447:Peptide Hydrolases; D012697:Serine Endopeptidases; C021433:IgA-specific serine endopeptidase