Cat and dog ownership during/after the first year of life and risk for sensitization and reported allergy symptoms at age 13

Background: Avoidance of pets as a strategy for preventing atopic diseases has been questioned. This study aimed to identify the risk of sensitization and allergic symptoms at age 13 in relation to dog- and cat-keeping during and after the first year of life. Methods: The study included all children born at 6stersund Hospital in Northern Sweden between February 1996 and January 1997 (n = 1231). At inclusion, parents were asked to answer questionnaires about lifestyle, including cat- and dog-keeping. Dog allergy, cat allergy, hay fever, and asthma were diagnosed based on parental reported allergic symptoms at 13 years of age (n = 834). The risks of sensitization or allergy in relation to dog- and cat-keeping during and after the first year of life were analyzed with logistic regression. To adjust for reverse causation, all subjects that had reported avoidance of pets due to allergic symptoms of the child or allergy in the family (n = 177) were excluded. Results: Dog- or cat-keeping during the first year of life reduced the risk of sensitization to dog or cat allergens, respectively, and to birch and to at least one of the 10 allergens tested. Cat-keeping, both during and after the first year of life, reduced the risk of cat allergy and hay fever. Having a dog at home during the first year of life reduced the risk of dog and cat allergy, whereas dog-keeping after the first year of life did not affect allergic symptoms. Conclusions: Cat ownership, either during or after the first year of life, may be a strategy for preventing the development of cat allergy and hay fever later in life. Dog ownership reduced the risk of sensitization to dog and birch allergen, and also the risk of cat and dog allergy, but had no effect on hay fever

The Heterogeneity of Asthma Phenotypes in Children and Young Adults

Objective. Genetic heterogeneity and risk factor distribution was analyzed in two previously proposed asthma phenotypes. Method. A sample of 412 subjects was investigated at 7-8, 12-13, and 21-22 years of age with questionnaires, skin prick tests, and genetic analysis of IL-4 receptor (IL4R) single-nucleotide polymorphisms. The sample was subdivided in one group with no asthma, and two groups with asthma separated by age of onset of symptoms, namely, early onset asthma (EOA) and late onset asthma (LOA). Risk factors and IL4R markers were analyzed in respect to asthma phenotypes. Results. EOA and LOA groups were both associated with atopy and a maternal history of asthma. Female gender was more common in LOA, whereas childhood eczema, frequent colds in infancy, and a paternal history of asthma were more common in EOA. The AA genotype of rs2057768 and the GG genotype of rs1805010 were more common in LOA, whereas the GG genotype of rs2107356 was less common in EOA. Conclusion. Our data suggest that early and late onset asthma may be of different endotypes and genotypes

Cord Blood Levels of EPA, a Marker of Fish Intake, Correlate with Infants\u27 T- and B-Lymphocyte Phenotypes and Risk for Allergic Disease

Maternal fish intake during pregnancy has been associated with reduced allergy development in the offspring and here, we hypothesized that components of fish stimulate fetal immune maturation. The aim of this study was to investigate how maternal fish intake during pregnancy and levels of n-3 long-chain polyunsaturated fatty acids (LCPUFAs) in the infant\u27s cord serum correlated with different subsets of B- and T-cells in cord blood and B-cell activating factor (BAFF) in cord plasma, and with doctor-diagnosed allergy at 3 and 8 years of age in the FARMFLORA birth-cohort consisting of 65 families. Principal component analysis showed that infant allergies at 3 or 8 years of age were negatively associated with the proportions of n-3 LCPUFAs (eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) in infant cord serum, which, in turn correlated positively with maternal fish intake during pregnancy. Both maternal fish intake and cord serum n-3 LCPUFAs correlated negatively to CD5(+) B cells and the FOXP3(+)CD25(high) of the CD4(+) T cell subsets in cord blood, but not to BAFF in cord plasma. Our observational study suggests that fish might contain components that promote maturation of the infant\u27s immune system in a manner that protects against allergy development

Umbilical cord blood metabolome differs in relation to delivery mode, birth order and sex, maternal diet and possibly future allergy development in rural children

Allergy is one of the most common diseases among young children yet all factors that affect development of allergy remain unclear. In a small cohort of 65 children living in the same rural area of south-west Sweden, we have previously found that maternal factors, including prenatal diet, affect childhood allergy risk, suggesting that in utero conditions may be important for allergy development. Here, we studied if metabolites in the umbilical cord blood of newborns may be related to development of childhood allergy, accounting for key perinatal factors such as mode of delivery, birth order and sex. Available umbilical cord blood plasma samples from 44 of the participants were analysed using gas chromatography-mass spectrometry metabolomics; allergy was diagnosed by specialised paediatricians at ages 18 months, 3 years and 8 years and included eczema, asthma, food allergy and allergic rhinoconjunctivitis. Nineteen cord blood metabolites were related to future allergy diagnosis though there was no clear pattern of up- or downregulation of metabolic pathways. In contrast, perinatal factors birth order, sex and mode of delivery affected several energy and bio-synthetic pathways, including glutamate and aspartic acid—histidine metabolism (p = 0.004) and the tricarboxylic acid cycle (p = 0.006) for birth order; branched chain amino acid metabolism (p = 0.0009) and vitamin B6 metabolism (p = 0.01) for sex; and glyoxylate and dicarboxylic acid metabolism (p = 0.005) for mode of delivery. Maternal diet was also related to some of the metabolites associated with allergy. In conclusion, the cord blood metabolome includes individual metabolites that reflect lifestyle, microbial and other factors that may be associated with future allergy diagnosis, and also reflects temporally close events/factors. Larger studies are required to confirm these associations, and perinatal factors such as birth order or siblings must be considered in future cord-blood metabolome studies

Fecal short chain fatty acids in children living on farms and a link between valeric acid and protection from eczema

Children growing up on farms have low rates of allergy, but the mechanism for this protective effect has not been fully elucidated. Short chain fatty acids (SCFAs) produced by the gut microbiota may play a role in protection from allergy. We measured fecal SCFA levels in samples collected from 28 farming and 37 control children over the first 3\ua0years of life using gas chromatography. Data on diet and other host factors were recorded and allergy was diagnosed at 8\ua0years of age. Among all children, median propionic and butyric acid concentration increased over the first 3\ua0years, and longer SCFAs typically appeared by 1\ua0year of age. Farm children had higher levels of iso-butyric, iso-valeric and valeric acid at 3\ua0years of age than rural controls. In addition, children with elder siblings had higher levels of valeric acid at 3\ua0years of age, and dietary factors also affected SCFA pattern. High levels of valeric acid at 3\ua0years of age were associated with low rate of eczema at 8\ua0years of age. The fecal SCFA pattern in farm children suggests a more rapid maturation of the gut microbiota. Valeric acid or associated microbes may have protective potential against eczema

Increase of allergic diseases in schoolchildren. The significance of pets and other environmental components

Objectives: 1) To compare the prevalence of allergic diseases in schoolchildren between 1979 and 1991 in two Swedish regions with differing climates, Kiruna in the northern inland mountains, north of the Arctic Circle, and Göteborg on the south-west coast. 2) To study the changes in allergic diseases and sensitisation during a 5 year follow-up period. 3) To evaluate the influence of parental history, residential characteristics, pet exposure during first year of life and other background factors on allergy development.Methods: Two cross-sectional questionnaire based studies, one in 1979 including 4255 7-year-olds and one in 1991 including 2481 7-9 year old children. The study in 1991 was followed by a validating interview and skin-prick tests in a stratified and population based sub-sample of 412 children, 7-8 year old. The sub-sample was followed-up after five years (1996) with a new questionnaire, interview and skin prick tests. The same questions about disease were used at all occasions, in 1979, 1991 and 1996. In 1991 new questions focused on parental history and different background factors. In 1996, it focused on early pet-keeping and factors influencing a family's decision not to have pets. Results: The prevalence of asthma increased from 2.5% to 5.7% between 1979 and 1991. Allergic rhino-conjunctivitis (ARC) from 5.4% to 8.1% and eczema from 7.0% to 18.3%. In 1991, at 7-9 years of age, a higher prevalence of eczema and sensitisation was observed in Kiruna. At the follow-up in 1996, at 12-13 years of age, similar prevalence figures were seen in the two regions for asthma (8.5%), ARC (17.2%) and eczema (23.4%). Sensitisation remained more common in Kiruna (38.1%) than in Göteborg (22.5%). Risk factors for allergy development were parental history of allergy, damp dwellings and birth during autumn/winter. Siblings and pet-keeping during first year of life were associated with less allergy. Boys were more often sensitised to horse, despite a low frequency in horseback riding as compared to girls. Conclusions: The prevalence of allergic diseases in schoolchildren doubled during the 12 year period from 1979 to 1991. Damp dwellings and birth during autumn/winter were associated with an increased risk of allergy development; highlighting the association between indoor climate and allergy development. Less allergy was seen in children with siblings and in children with direct animal contacts, especially during first year of life. The findings are interpreted as if factors associated with "less hygiene" and high allergen exposure may have protective effects

Cat and dog ownership during/after the first year of life and risk for sensitization and reported allergy symptoms at age 13

Background: Avoidance of pets as a strategy for preventing atopic diseases has been questioned. This study aimed to identify the risk of sensitization and allergic symptoms at age 13 in relation to dog‐ and cat‐keeping during and after the first year of life. Methods: The study included all children born at Östersund Hospital in Northern Sweden between February 1996 and January 1997 (n = 1231). At inclusion, parents were asked to answer questionnaires about lifestyle, including cat‐ and dog‐keeping. Dog allergy, cat allergy, hay fever, and asthma were diagnosed based on parental reported allergic symptoms at 13 years of age (n = 834). The risks of sensitization or allergy in relation to dog‐ and cat‐keeping during and after the first year of life were analyzed with logistic regression. To adjust for reverse causation, all subjects that had reported avoidance of pets due to allergic symptoms of the child or allergy in the family (n = 177) were excluded. Results: Dog‐ or cat‐keeping during the first year of life reduced the risk of sensitization to dog or cat allergens, respectively, and to birch and to at least one of the 10 allergens tested. Cat‐keeping, both during and after the first year of life, reduced the risk of cat allergy and hay fever. Having a dog at home during the first year of life reduced the risk of dog and cat allergy, whereas dog‐keeping after the first year of life did not affect allergic symptoms. Conclusions: Cat ownership, either during or after the first year of life, may be a strategy for preventing the development of cat allergy and hay fever later in life. Dog ownership reduced the risk of sensitization to dog and birch allergen, and also the risk of cat and dog allergy, but had no effect on hay fever

No association between allergy and current 25-hydroxy vitamin D in serum or vitamin D intake

AimVitamin D may be involved in allergy development, but there is conflicting evidence. We investigated if dietary intake of vitamin D and levels of 25OHD in serum differed between allergic and nonallergic adolescents and if serum 25OHD correlated with dietary intake of vitamin D or season of blood sampling.MethodsSerum 25-hydroxy vitamin D (25OHD) levels were analysed in 13-year-old subjects with atopic eczema (n = 55), respiratory allergy (n = 55) or no allergy (n = 55). Intake of fat-containing foods was assessed by food-frequency questionnaires, and total daily vitamin D intake was calculated. Logistic regression was used to adjust for gender, parental allergy and time of blood sampling.ResultsSubjects with atopic eczema or respiratory allergy did not differ from nonallergic controls regarding serum 25OHD levels or calculated vitamin D intake. Subjects sampled in the autumn had significantly higher levels of serum 25OHD than subjects sampled in the winter or spring. Serum 25OHD levels correlated to consumption of vitamin D-fortified lean milk (p = 0.001).ConclusionThe findings suggest no association between allergy and 25OHD levels in serum or vitamin D intake in adolescents. Serum 25OHD levels correlated to intake of vitamin D-fortified lean milk

Maternal Intake of Cow's Milk during Lactation Is Associated with Lower Prevalence of Food Allergy in Offspring

Maternal diet during pregnancy and lactation may affect the propensity of the child to develop an allergy. The aim was to assess and compare the dietary intake of pregnant and lactating women, validate it with biomarkers, and to relate these data to physician-diagnosed allergy in the offspring at 12 months of age. Maternal diet during pregnancy and lactation was assessed by repeated semi-quantitative food frequency questionnaires in a prospective Swedish birth cohort (n = 508). Fatty acid proportions were measured in maternal breast milk and erythrocytes. Allergy was diagnosed at 12 months of age by a pediatrician specialized in allergy. An increased maternal intake of cow's milk during lactation, confirmed with biomarkers (fatty acids C15:0 and C17:0) in the maternal blood and breast milk, was associated with a lower prevalence of physician-diagnosed food allergy by 12 months of age. Intake of fruit and berries during lactation was associated with a higher prevalence of atopic eczema at 12 months of age. Our results suggest that maternal diet modulates the infant's immune system, thereby influencing subsequent allergy development

High Rate of Transfer of Staphylococcus aureus from Parental Skin to Infant Gut Flora

Many Swedish infants carry Staphylococcus aureus in their intestinal microflora. The source of this colonization was investigated in 50 families. Infantile S. aureus strains were isolated from rectal swabs and stool samples at 3 days and at 1, 2, 4, and 8 weeks of age. The strains were identified by using the random amplified polymorphic DNA method and compared to strains from swab cultures of the mothers' hands, nipples, and nares and from the fathers' hands and nares. Maternal stool samples were also obtained at a later stage to compare infant and adult intestinal S. aureus colonization. Although 60% of 1-month-old children had S. aureus in the stools, this was true of only 24% of the mothers. The median population numbers in colonized individuals also differed: 10(6.8) CFU/g of feces among infants at 2 weeks of age versus 10(3.2) CFU/g of feces in the mothers. Of S. aureus strains in the stools of 3-day-old infants, 90% were identical to a parental skin strain. A total of 96% of infants whose parents were S. aureus skin carriers had S. aureus in their feces and 91% had the same strain as at least one of the parents. In comparison, only 37% of infants to S. aureus-negative parents had S. aureus in the stool samples. Thus, infantile intestinal S. aureus colonization was strongly associated with parental skin S. aureus carriage (P = 0.0001). These results suggest that S. aureus on parental skin establish readily in the infantile gut, perhaps due to poor competition from other gut bacteria