RESUMO
There is an urgent need to identify environmental risk and protective factors in early life for the prevention of allergy. Our study demonstrates the presence of respiratory allergen from house dust mite, Der p 1, in human breast milk. Der p 1 in milk is immunoreactive, present in similar amounts as dietary egg antigen, and can be found in breast milk from diverse regions of the world. In a mouse model of asthma, oral exposure to Der p through breast milk strongly promotes sensitization rather than protect the progeny as we reported with egg antigen. These data highlight that antigen administration to the neonate through the oral route may contribute to child allergic sensitization and have important implications for the design of studies assessing early oral antigen exposure for allergic disease prevention. The up-to-now unknown worldwide presence of respiratory allergen in maternal milk allows new interpretation and design of environmental control epidemiological studies for allergic disease prevention.
Assuntos
Alérgenos/imunologia , Asma/imunologia , Leite Humano/imunologia , Pyroglyphidae/imunologia , Animais , Antígenos de Dermatophagoides/imunologia , Proteínas de Artrópodes/imunologia , Colostro/imunologia , Cisteína Endopeptidases/imunologia , Exposição Ambiental/efeitos adversos , Feminino , Humanos , GravidezRESUMO
There is strong evidence from animal models that placental and/or breast milk-mediated transfer of maternal allergen-specific IgG prevents allergic immune responses in the progeny. Both human and animal data also point to IgA as having an important regulatory role. In contrast, little is known about maternal transfer of IgG and IgA specific for respiratory allergens in humans. Dermatophagoides pteronyssinus (Der p) is an indoor allergen that is a major cause of asthma worldwide. We analysed maternal to child Der p-specific IgG and IgA transfer in a cohort of 77 paired maternal and child samples. We found Der p-specific IgG and its IgG1, IgG2 and IgG4 subclasses in all cord blood samples. Except for IgG1, cord levels were higher in newborns from atopic mothers (n = 29) compared to non-atopic mothers (n = 48). Der p-specific IgA was found in all colostrum samples and levels were independent of maternal atopic status. Notably, anti-Der p IgG was also found in colostrum and levels were higher in atopic mothers. We believe that our work is a critical first step in the identification of early factors that may impact asthma development and should guide the development of clinical studies that assess whether Der p-specific IgG and IgA protect children from allergy as demonstrated in animal models.