Aberrant IgA responses to the gut microbiota during infancy precedes asthma and allergy development

Publication date: Available online 13 August 2016
Source:Journal of Allergy and Clinical Immunology
Author(s): Majda Dzidic, Thomas R. Abrahamsson, Alejandro Artacho, Bengt Björkstén, Maria Carmen Collado, Alex Mira, Maria C. Jenmalm
BackgroundWhile a reduced gut microbiota diversity and low mucosal total IgA levels in infancy have been associated with allergy development, IgA responses to the gut microbiota have not yet been studied.ObjectiveWe sought to determine the proportions of IgA coating together with the characterization of the dominant bacteria, bound to IgA or not, in infant stool samples in relation to allergy development.MethodsA combination of flow cytometry cell sorting and deep sequencing of the 16S rDNA gene was used to characterize the bacterial recognition patterns by IgA in stool samples collected at 1 and 12 month of age from children staying healthy or developing allergic symptoms up to seven years of age.ResultsThe children developing allergic manifestations, particularly asthma, during childhood had a lower proportion of IgA bound to fecal bacteria at 12 months of age compared with healthy children. These alterations cannot be attributed to differences in IgA levels or bacterial load between the two groups. Moreover, the bacterial targets of early IgA responses (including the coating of Bacteroides genus) as well as the IgA recognition patterns differed between healthy children and children developing allergic manifestations. Altered IgA recognition patterns in children developing allergy were observed also already at 1 month of age, when the IgA antibodies are predominantly maternally derived in breast fed children.ConclusionAn aberrant IgA responsiveness to the gut microbiota during infancy precedes asthma and allergy development, possibly indicating an impaired mucosal barrier function in allergic children.Key messageAberrant and reduced IgA responses to the gut microbiota during infancy precede development of asthma and allergic disease during the first seven years of life.

Teaser

Early characterization of IgA coating patterns may represent a novel way to identify infants with increased risk to develop asthma and allergic disease. Moreover, interventions enhancing infant mucosal barrier function may represent efficacious preventive strategies required to combat the asthma and allergy epidemic.


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