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Maternal allergen-specific IgG might protect the child against allergic sensitization.
Lupinek, C, Hochwallner, H, Johansson, C, Mie, A, Rigler, E, Scheynius, A, Alm, J, Valenta, R
The Journal of allergy and clinical immunology. 2019;144(2):536-548
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Analysis of allergen-specific IgE responses in birth cohorts with allergens has provided detailed information regarding the development of specific IgE responses in children. Data regarding early development of allergen-specific IgG is needed. The aim of this study is to investigate whether maternal allergen-specific IgG can protect against IgE sensitization in their children. Plasma samples were taken from mothers during the third trimester, cord blood, breast milk collected 2 months after delivery; and from children at 6, 12, and 60 months of age. These samples were analysed for IgG reactivity to 164 allergens in 99 families. IgE sensitizations to allergens were determined at 5 years of age in the children. Children who were IgE sensitized against an allergen at 5 years of age had significantly higher allergen-specific IgG levels than non-sensitised children. For all 164 tested allergens, children from mothers with higher levels of specific plasma IgG levels against an allergen had no IgE sensitizations against that allergen at 5 years of age. High levels of allergen-specific IgG in mothers during the third trimester and in cord blood seem to protect against allergic sensitization in offspring. This finding has implications for allergy prevention.
Abstract
BACKGROUND Analysis of allergen-specific IgE responses in birth cohorts with microarrayed allergens has provided detailed information regarding the evolution of specific IgE responses in children. High-resolution data regarding early development of allergen-specific IgG are needed. OBJECTIVE We sought to analyze IgG reactivity to microarrayed allergens in mothers during pregnancy, in cord blood samples, in breast milk, and in infants in the first years of life with the aim to investigate whether maternal allergen-specific IgG can protect against IgE sensitization in the offspring. METHODS Plasma samples from mothers during the third trimester, cord blood, breast milk collected 2 months after delivery, and plasma samples from children at 6, 12, and 60 months of age were analyzed for IgG reactivity to 164 microarrayed allergens (ImmunoCAP ISAC technology) in 99 families of the Swedish birth cohort Assessment of Lifestyle and Allergic Disease During Infancy (ALADDIN). IgE sensitizations to microarrayed allergens were determined at 5 years of age in the children. RESULTS Allergen-specific IgG reactivity profiles in mothers, cord blood, and breast milk were highly correlated. Maternal allergen-specific IgG persisted in some children at 6 months. Children's allergen-specific IgG production occurred at 6 months and reflected allergen exposure. Children who were IgE sensitized against an allergen at 5 years of age had significantly higher allergen-specific IgG levels than nonsensitized children. For all 164 tested allergens, children from mothers with increased (>30 ISAC standardized units) specific plasma IgG levels against an allergen had no IgE sensitizations against that allergen at 5 years of age. CONCLUSION This is the first detailed analysis of the molecular IgG recognition profile in mothers and their children in early life. High allergen-specific IgG reactivity in the mother's plasma and breast milk and in cord blood seemed to protect against allergic sensitization at 5 years of age.
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Swimming pool exposure is associated with autonomic changes and increased airway reactivity to a beta-2 agonist in school aged children: A cross-sectional survey.
Cavaleiro Rufo, J, Paciência, I, Silva, D, Martins, C, Madureira, J, Oliveira Fernandes, E, Padrão, P, Moreira, P, Delgado, L, Moreira, A
PloS one. 2018;13(3):e0193848
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Studies have shown an association between swimming in chemically-treated pools and a higher risk of asthma in children, although the mechanism is not fully understood. This study aimed to investigate how swimming pool attendance influences lung and nervous system function in school-aged children. Around 800 children were classified as current swimmers (CS), past swimmers (PS) or non-swimmers (NS). The children underwent several tests to determine their lung function and allergic response to common allergens. Parasympathetic nervous system function was tested by measuring the speed at which their pupils constricted in response to light. The current swimmers group had significantly lower pupil constriction speeds compared to PS and NS, suggesting a poorer functioning of the autonomic nervous system, possibly due to inflammation resulting from swimming pool chemical exposure. CS experienced greater constriction of the airways compared to NS. A non-significant trend for a higher risk of asthma, atopic eczema and rhinitis, was observed in swimmers. The authors concluded that swimming pool attendance appears to be associated with autonomic nervous system changes and increased baseline airway smooth muscle constriction even in children without asthma.
Abstract
BACKGROUND Endurance swimming exercises coupled to disinfection by-products exposure has been associated with increased airways dysfunction and neurogenic inflammation in elite swimmers. However, the impact of swimming pool exposure at a recreational level on autonomic activity has never been explored. Therefore, this study aimed to investigate how swimming pool attendance is influencing lung and autonomic function in school-aged children. METHODS A total of 858 children enrolled a cross sectional survey. Spirometry and airway reversibility to beta-2 agonist, skin-prick-tests and exhaled nitric oxide measurements were performed. Pupillometry was used to evaluate autonomic nervous function. Children were classified as current swimmers (CS), past swimmers (PS) and non-swimmers (NS), according to the amount of swimming practice. RESULTS Current swimmers group had significantly lower maximum and average pupil constriction velocities when compared to both PS and NS groups (3.8 and 5.1 vs 3.9 and 5.3 vs 4.0 and 5.4 mm/s, p = 0.03 and p = 0.01, respectively). Moreover, affinity to the beta-2 agonist and levels of exhaled nitric oxide were significantly higher in CS when compared to NS (70 vs 60 mL and 12 vs 10 ppb, p<0.01 and p = 0.03, respectively). A non-significant trend for a higher risk of asthma, atopic eczema and allergic rhinitis was found with more years of swimming practice, particularly in atopic individuals (β = 1.12, 1.40 and 1.31, respectively). After case-case analysis, it was possible to observe that results were not influenced by the inclusion of individuals with asthma. CONCLUSIONS Concluding, swimming pool attendance appears to be associated with autonomic changes and increased baseline airway smooth muscle constriction even in children without asthma.