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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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SunGold Kiwifruit Supplementation of Individuals with Prediabetes Alters Gut Microbiota and Improves Vitamin C Status, Anthropometric and Clinical Markers.
Wilson, R, Willis, J, Gearry, RB, Hughes, A, Lawley, B, Skidmore, P, Frampton, C, Fleming, E, Anderson, A, Jones, L, et al
Nutrients. 2018;10(7)
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Increased plasma glucose levels are linked with increased oxidative stress. An increase in the uptake of antioxidants such as vitamin C through diet has been demonstrated by several studies as contributing to the maintenance of normal glucose levels and reducing the risk factors for Type 2 diabetes. The aim of this study was to investigate the vitamin C status, anthropometric measurements and faecal microbiota of an individual on consumption of high vitamin C kiwi fruit for a period of 12 weeks. Baseline measures were compared at the end of 12 weeks resulting in significant increase in plasma vitamin C status (14 µmol/L, p < 0.001). Significant reduction in blood pressure measurement (4 mmHg, p = 0.029), reduction in waist- to- hip ratio and waist- circumference, decrease in blood glucose marker HbA1c (1 mmol/mol, p = 0.005) and increase in fasting glucose (0.1 mmol/L, p = 0.046) were also observed at the end of twelve weeks. Faecal microbiota composition showed an increase in the abundance of uncharacterised bacterial family. The authors concluded that these result were not sufficiently significant to draw conclusions and further studies with larger sample sizes are required to confirm the outcomes of this study.
Abstract
Kiwifruit are a nutrient dense food and an excellent source of vitamin C. Supplementation of the diet with kiwifruit enhances plasma vitamin C status and epidemiological studies have shown an association between vitamin C status and reduced insulin resistance and improved blood glucose control. In vitro experiments suggest that eating kiwifruit might induce changes to microbiota composition and function; however, human studies to confirm these findings are lacking. The aim of this study was to investigate the effect of consuming two SunGold kiwifruit per day over 12 weeks on vitamin C status, clinical and anthropometric measures and faecal microbiota composition in people with prediabetes. This pilot intervention trial compared baseline measurements with those following the intervention. Participants completed a physical activity questionnaire and a three-day estimated food diary at baseline and on completion of the trial. Venous blood samples were collected at each study visit (baseline, 6, 12 weeks) for determination of glycaemic indices, plasma vitamin C concentrations, hormones, lipid profiles and high-sensitivity C-reactive protein. Participants provided a faecal sample at each study visit. DNA was extracted from the faecal samples and a region of the 16S ribosomal RNA gene was amplified and sequenced to determine faecal microbiota composition. When week 12 measures were compared to baseline, results showed a significant increase in plasma vitamin C (14 µmol/L, p < 0.001). There was a significant reduction in both diastolic (4 mmHg, p = 0.029) and systolic (6 mmHg, p = 0.003) blood pressure and a significant reduction in waist circumference (3.1 cm, p = 0.001) and waist-to-hip ratio (0.01, p = 0.032). Results also showed a decrease in HbA1c (1 mmol/mol, p = 0.005) and an increase in fasting glucose (0.1 mmol/L, p = 0.046), however, these changes were small and were not clinically significant. Analysis of faecal microbiota composition showed an increase in the relative abundance of as yet uncultivated and therefore uncharacterised members of the bacterial family Coriobacteriaceae. Novel bacteriological investigations of Coriobacteriaceae are required to explain their functional relationship to kiwifruit polysaccharides and polyphenols.