Occurrence and subclass distribution of IgG antibodies to dietary antigens in children with atopic dermatitis and in their mothers.

Occurrence and subclass distribution of IgG to alpha-lactalbumin (ALA), beta-lactoglobulin (BLG), and ovalbumin (OA) have been determined in 30 children with atopic dermatitis (AD) and in their mothers. Thirty nonatopic (NA) children and their mothers were studied as controls. Total IgE and IgE to ALA, BLG, OA, Dermatophagoides pteronyssinus, and Lolium perenne were also investigated. The main purpose of this study was to determine whether in humans, as observed in animals, maternal allergen-specific IgG influences allergen-specific IgE synthesis in children. IgG1, IgG2, IgG3, and IgG4 to ALA, and IgG1 and IgG2 to OA were more frequent in AD children than in NA children. As compared with mothers of NA children, mothers of AD children had similar frequency and levels of IgG subclasses to BLG and to OA, but a higher frequency of IgG1, IgG2, and IgG3 to ALA. In no case did total or allergen-specific IgE levels correlate with any subclass of allergen-specific IgG, which in turn influenced neither total IgE levels nor allergen-specific IgE distribution. The presence of allergen-specific IgG of any subclass in mothers was not associated with modifications in total IgE levels nor in allergen-specific IgG subclass distribution in AD children. But occurrence of IgE to OA was higher in AD children whose mothers had IgG4 to OA. This finding may be a model of interference in specific IgE response in the child caused by isotype response in the mother.