Human immunology from the Eisenbarth lab
"The aim of our study was to characterize infant gut food-specific IgA responses and determine whether gut and plasma food-specific IgA are related to tolerance to food allergens. We found that non–food-allergic infants make gut peanut-specific IgA. We next demonstrated that gut peanut-specific IgA did not correlate with measures of future peanut allergy outcome nor did it correlate with peanut tolerance. We also observed that gut egg white-specific IgA was higher in egg-allergic children and did not predict outgrowth of egg allergy. Our data also revealed that there are no differences in the epitopes targeted by gut peanut-specific IgA between peanut-allergic and nonallergic children but that epitope specificity is different between gut peanut-specific IgA and plasma peanut IgE. Overall, these findings challenge the commonly presumed protective role of food-specific IgA."