title: Early Exposure to Respiratory Allergens by Placental Transfer and Breastfeeding.
abstract: The relationship between allergen exposure and the onset of or protection from allergic diseases remains unclear. Many factors could be related to immunological responses, such as the age when the exposure occurs, type of allergen, timing, dose, and allergen route. In this study, we investigated whether exposure to respiratory allergens could occur in pregnancy or early life. In particular, we assessed whether Der p 1 and Blo t 5, as well as specific antibodies against these allergens, could be detected in 90 paired cord blood and colostrum samples. Der p 1 was detected in 58.6% of colostrum and 29% of cord blood samples, whereas Blot 5 was positive in 41.3% and 9.6% of the samples, respectively. Similar to specific IgA, which could be detected in all samples for both mites, specific IgG was found in a high number of colostrum samples, 93.5% and 94.8% for Dp and Bt, respectively. Although allergens were not detected in all cord blood samples, a high percentage of them (≥95%) were positive for specific IgM to both mites in cord blood samples, suggesting that neonates can be exposed and sensitized to airborne allergens during pregnancy. Many studies have attempted to correlate allergen exposure or its prevention in early infancy with the onset of or protection from allergic diseases. However, conflicting and inconsistent data do not show a clear correlation with or suggest a way to prevent allergen sensitization. Nevertheless, these unconvincing results could be better understood if the relationship with many aspects of allergen exposure after pregnancy could be clarified. Thus, it is necessary to address basic issues related to allergen exposure, including the development of reproducible, standardized and reliable methods, and to determine how and where the exposure occurs.
authors.affiliation: Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Macchiaverni
authors.affiliation: Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Leandro H
authors.initials: LH
authors.lastname: Ynoue
authors.affiliation: Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Christina
authors.initials: C
authors.lastname: Arslanian
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM), U924 Université de Nice-Sophia Antipolis, Valbonne, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Verhasselt
authors.affiliation: Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
authors.forename: Antonio
authors.initials: A
authors.lastname: Condino-Neto
mesh_terms: D000485:Allergens / Q000276:immunology*; D000906:Antibodies / Q000276:immunology; D039741:Antigens, Dermatophagoides / Q000276:immunology; D001942:Breast Feeding; D003126:Colostrum / Q000276:immunology; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology; D007231:Infant, Newborn / Q000276:immunology; D019570:Inhalation Exposure; D010920:Placenta / Q000276:immunology*; D011247:Pregnancy
chemical_list: D000485:Allergens; D000906:Antibodies; D039741:Antigens, Dermatophagoides