Anna Sandin

Microflora-associated characteristics in faeces from allergic and nonallergic infants

Background 

Asthma and allergic symptoms in relation to house dust endotoxin: Phase Two of the International Study on Asthma and Allergies in Childhood (ISAAC II)

Background Several studies have consistently reported inverse associations between exposure to endotoxin in house dust and atopy. With regard to the association between house dust endotoxin and asthma, the results are inconsistent.

Atopy among schoolchildren in northern and southern Sweden in relation to pet ownership and early life events.

Studies have suggested a higher prevalence of asthma and allergies in northern, as compared to southern, Scandinavia. The aim of this study was to evaluate regional differences in atopy in relation to pet ownership and certain early life events among schoolchildren (n = 2108) aged 10–11 years from Linköping in southern Sweden and Östersund in northern Sweden. The parents completed a questionnaire, comprising questions on home environment, heredity, socio‐economic conditions, and the core questions on symptoms from the International Study of Asthma and Allergies in Childhood. The children were skin‐prick tested to eight common inhalant allergens. Information on maternal smoking habits, gestational age, and anthropometric measures were obtained from the Swedish Medical Birth Registry. The prevalence of atopic symptoms and sensitization to pollen were similar in Östersund and in Linköping. A higher prevalence of sensitization to animal dander among children in Östersund could be linked to a higher occurrence of pets in the community. Current cat ownership was related to less sensitivity to cat allergen but only in children with an atopic heredity. Ponderal index > 30 kg/m3 was related to an increased risk of atopic sensitization, both in Linköping (adjusted odds ratio 2.1; 95% confidence interval 1.1–4.0) and in Östersund (adjusted odds ratio 2.0; 95% confidence interval 1.1–3.5). Maternal smoking during pregnancy was related to an increased risk of atopic sensitization among children in Linköping, whereas current smoking was associated with a decreased risk of sensitization in Östersund. In conclusion, we demonstrated that a high occurrence of pets in the community was associated with sensitization, whereas atopic symptoms were essentially unaffected. This study has also suggested an association between body size at birth and atopic sensitization at 10–11 years of age.

High body mass index, asthma and allergy in Swedish schoolchildren participating in the International Study of Asthma and Allergies in Childhood: Phase II

Aim: To assess the relationship between high body mass index (BMI) and asthma and atopic manifestations in 12‐y‐old children. Methods: The relationship between high BMI and asthma symptoms was studied in 457 sixth‐grade children, with (n= 161) and without (n= 296) current wheeze. High BMI was defined as ±75th percentile of gender‐specific BMI reference values for Swedish children at 12 y of age; overweight as a subgroup of high BMI was defined as ±95th percentile. Children with a BMI >75th percentile served as controls. Questionnaires were used to assess asthmatic and allergic symptoms, and bronchial hyperresponsiveness was assessed by hypertonic saline provocation tests. Results: Current wheeze was associated with high BMI after adjustment for confounding factors (adjusted OR 1.7, 95% CI 1.0–2.5) and overweight had an even more pronounced effect (adjusted OR 1.9, 95% CI 1.0–3.6). In addition, asthma severity was associated with high BMI, as evaluated by the number of wheezing episodes during the previous 12 mo among the wheezing children (adjusted OR 2.0, 95% CI 1.0–4.0). There was also an association between high BMI and the presence of eczema in wheezing children (adjusted OR 2.2, 95% CI 1.0–4.6). However, high BMI was not significantly associated with hay fever, positive skin prick tests or bronchial hyperresponsiveness.

Wheezing in relation to atopy and environmental factors in Estonian and Swedish schoolchildren.

Background The prevalence of asthma and allergic diseases is significantly lower in post socialist Eastern Europe than in Western industrialized countries. The reason for this difference is largely unknown. Different types of childhood wheezing could be related to different risk factors.

Development of atopy and wheezing symptoms in relation to heredity and early pet keeping in a Swedish birth cohort

The role of pet keeping during infancy for the development of allergy and asthma is still controversial. The objective of this population‐based birth cohort study was to assess the development of atopy and different wheezing phenotypes during the first 4 yr of life in relation to heredity and early pet keeping. The cohort comprised all 1228 infants living in a Swedish county who were born over a 1‐yr period. The parents replied to repeated questionnaires and 817 of the children were skin prick tested both at 1 and 4 yr. Cat keeping during the first year of life was associated with an increased risk of a positive skin prick test to cat at 1 yr of age [odds ratio (OR) 2.2, 95% confidence interval (CI) 0.9–5.6], but neither with sensitivity nor clinical symptoms of allergy at 4 yr. Dog keeping during the first year of life was associated with an increased risk of early‐onset transient wheezing, but only in children with parental asthma (adjusted OR 4.3, 95% CI 1.5–12.1). In contrast, early dog keeping had an inverse association with sensitivity to pollen allergen at 4 yr (adjusted OR 0.3, 95% CI 0.1–0.9) and late‐onset wheezing (adjusted OR 0.4, 95% CI 0.2–1.0). Thus, pet keeping during the first year of life was not associated with an increased risk of atopy at 4 yr, although a positive SPT to cat was more common at 1 yr. Our findings may even suggest that dog keeping during the first year of life might provide some protection from pollen allergy and late‐onset wheezing and increase the risk of early‐onset transient wheezing in children with heredity for asthma.

Faecal short chain fatty acid pattern and allergy in early childhood.

Aim: To investigate whether functional changes of the gut flora over time were related to sensitization and allergic symptoms at four years of age.

Prevalence of self-reported food allergy and IgE antibodies to food allergens in Swedish and Estonian schoolchildren

Objective:To compare the prevalence of self-reported food allergy and IgE antibodies to food allergens in wheezing and non-wheezing Estonian and Swedish schoolchildren, in the light of the disparities in the standard of living, food consumption and prevalence of respiratory allergies that still exist between Estonia and the Scandinavian countries.Design and setting:As a part of the ISAAC Phase II study, children from a random sample of schools in Tallinn in Estonia and Linköping and Östersund in Sweden participated in skin prick tests to inhalant allergens and the parents replied to questionnaires. IgE antibodies against a panel of food allergens (egg white, milk, soy bean, fish, wheat and peanut) were taken from children with questionnaire-reported wheezing and a random sample of nonwheezing children.Subjects:Children aged 10–11 y.Results:The prevalence of self-reported food allergy was similar in Estonia and Sweden and about twice as high in wheezing children than in nonwheezing children. In Estonia, however, 3% of the children with perceived food allergy reported reactions from at least four different foods, as compared to 31% in Sweden. The prevalence of sensitisation to food allergens was similar in wheezing and nonwheezing children in Estonia (8%) while, in Swedish children, IgE antibodies to food allergens were more likely among wheezing children (Linköping 38 vs 11%, crude OR 5.1, 95% CI 2.2–11.6, and Östersund 24 vs 7%, crude OR 4.1, 95% CI 1.9–8.5).Conclusion:Our study suggests that IgE-mediated food reactions were less likely in Estonian schoolchildren. Moreover, the perception of food allergy and thereby the meaning of self-reported food allergy appears to be different in the two countries.Sponsorship:This study was supported by a grant from the Swedish Foundation for Health Care Sciences and Allergy Research.

High salivary secretory IgA antibody levels are associated with less late-onset wheezing in IgE-sensitized infants

To cite this article: Sandin A, Björkstén B, Böttcher MF, Englund E, Jenmalm MC, Bråbäck L. High salivary secretory IgA antibody levels are associated with less late‐onset wheezing in IgE‐sensitized infants. Pediatr Allergy Immunol 2011; 22: 477–481.

High Levels of Both n-3 and n-6 Long-Chain Polyunsaturated Fatty Acids in Cord Serum Phospholipids Predict Allergy Development

Background Long-chain polyunsaturated fatty acids (LCPUFAs) reduce T-cell activation and dampen inflammation. They might thereby counteract the neonatal immune activation and hamper normal tolerance development to harmless environmental antigens. We investigated whether fatty acid composition of cord serum phospholipids affects allergy development up to age 13 years. Methods From a population-based birth-cohort born in 1996/7 and followed until 13 years of age (n = 794), we selected cases with atopic eczema (n = 37) or respiratory allergy (n = 44), as well as non-allergic non-sensitized controls (n = 48) based on diagnosis at 13 years of age. Cord and maternal sera obtained at delivery from cases and controls were analysed for proportions of saturated, monounsaturated and polyunsaturated fatty acids among serum phospholipids. Results The cord serum phospholipids from subject who later developed either respiratory allergy or atopic eczema had significantly higher proportions of 5/8 LCPUFA species, as well as total n-3 LCPUFA, total n-6 LCPUFA and total LCPUFA compared to cord serum phospholipids from controls who did not develop allergy (P<0.001 for all comparisons). Conversely, individuals later developing allergy had lower proportion of the monounsaturated fatty acid 18∶1n-9 as well as total MUFA (p<0.001) among cord serum phospholipids. The risk of respiratory allergy at age 13 increased linearly with the proportion of n-3 LCPUFA (Ptrend<0.001), n-6 LCPUFA (Ptrend = 0.001), and total LCPUFA (Ptrend<0.001) and decreased linearly with the proportions of total MUFA (Ptrend = 0.025) in cord serum phospholipids. Furthermore, Kaplan-Meier estimates of allergy development demonstrated that total LCPUFA proportion in cord serum phospholipids was significantly associated with respiratory allergy (P = 0.008) and sensitization (P = 0.002), after control for sex and parental allergy. Conclusion A high proportion of long-chain PUFAs among cord serum phospholipids may predispose to allergy development. The mechanism is unknown, but may involve dampening of the physiologic immune activation in infancy needed for proper maturation of the infants immune system.