Characteristics of infant formula consumed in the first months of life and allergy in the EDEN mother-child cohort

The evidence regarding the association between infant formula (IF) composition and the prevention of allergy and respiratory diseases remains sparse and inconclusive. This study aimed to evaluate whether some IF characteristics were associated with the risk of allergy or respiratory diseases in childhood. Among 1243 formula-fed children from the EDEN mother-child cohort, IF characteristics concerning long-chain polyunsaturated fatty acids (LCPUFAs) enrichment, prebiotic/probiotic enrichment, and hydrolysis of proteins were identified from the ingredients list. Eczema, wheezing, food allergy, asthma, and allergic rhinitis up to age 8 years were prospectively collected and summarized into four allergic and respiratory multimorbidity clusters. Associations between 4-month IF characteristics and risk of allergy or respiratory diseases were tested using logistic regressions adjusted on main confounders. The consumption of LCPUFA-enriched formula was not linked to allergic and respiratory multimorbidity clusters, but to a lower risk of any allergy, eczema, and wheezing. Probiotic-enriched formula consumption was associated with a lower risk of belonging to the 'Allergy without asthma' cluster (odds ratio [OR] [95% confidence interval, CI] = 0.63 [0.40-0.99]), and consumption of a formula enriched in Bifidobacterium lactis was associated with a lower risk of any allergy (OR [95% CI] = 0.59 [0.41-0.85]). Partially hydrolysed formula (pHF) consumption was associated with a higher risk of belonging to the 'Allergy without asthma' cluster (OR [95% CI] = 2.73 [1.65-4.51]). This study confirms the positive association between pHF consumption and the risk of allergy found in previous observational studies and suggests that consumption of LCPUFA-enriched or probiotic-enriched formula was associated with a lower risk of allergy.

An integrated molecular risk score early in life for subsequent childhood asthma risk

BACKGROUND

Numerous children present with early wheeze symptoms, yet solely a subgroup develops childhood asthma. Early identification of children at risk is key for clinical monitoring, timely patient-tailored treatment, and preventing chronic, severe sequelae. For early prediction of childhood asthma, we aimed to define an integrated risk score combining established risk factors with genome-wide molecular markers at birth, complemented by subsequent clinical symptoms/diagnoses (wheezing, atopic dermatitis, food allergy).

METHODS

Three longitudinal birth cohorts (PAULINA/PAULCHEN, n = 190 + 93 = 283, PASTURE, n = 1133) were used to predict childhood asthma (age 5-11) including epidemiological characteristics and molecular markers: genotype, DNA methylation and mRNA expression (RNASeq/NanoString). Apparent (ap) and optimism-corrected (oc) performance (AUC/R2) was assessed leveraging evidence from independent studies (Naïve-Bayes approach) combined with high-dimensional logistic regression models (LASSO).

RESULTS

Asthma prediction with epidemiological characteristics at birth (maternal asthma, sex, farm environment) yielded an ocAUC = 0.65. Inclusion of molecular markers as predictors resulted in an improvement in apparent prediction performance, however, for optimism-corrected performance only a moderate increase was observed (upto ocAUC = 0.68). The greatest discriminate power was reached by adding the first symptoms/diagnosis (up to ocAUC = 0.76; increase of 0.08, p = .002). Longitudinal analysis of selected mRNA expression in PASTURE (cord blood, 1, 4.5, 6 years) showed that expression at age six had the strongest association with asthma and correlation of genes getting larger over time (r = .59, p < .001, 4.5-6 years).

CONCLUSION

Applying epidemiological predictors alone showed moderate predictive abilities. Molecular markers from birth modestly improved prediction. Allergic symptoms/diagnoses enhanced the power of prediction, which is important for clinical practice and for the design of future studies with molecular markers.

Prenatal dietary exposure to mixtures of chemicals is associated with allergy or respiratory diseases in children in the ELFE nationwide cohort

INTRODUCTION

Prenatal exposure to environmental chemicals may be associated with allergies later in life. We aimed to examine the association between prenatal dietary exposure to mixtures of chemicals and allergic or respiratory diseases up to age 5.5 y.

METHODS

We included 11,638 mother-child pairs from the French "Étude Longitudinale Française depuis l'Enfance" (ELFE) cohort. Maternal dietary exposure during pregnancy to eight mixtures of chemicals was previously assessed. Allergic and respiratory diseases (eczema, food allergy, wheezing and asthma) were reported by parents between birth and age 5.5 years. Associations were evaluated with adjusted logistic regressions. Results are expressed as odds ratio (OR[95%CI]) for a variation of one SD increase in mixture pattern.

RESULTS

Maternal dietary exposure to a mixture composed mainly of trace elements, furans and polycyclic aromatic hydrocarbons (PAHs) was positively associated with the risk of eczema (1.10 [1.05; 1.15]), this association was consistent across sensitivity analyses. Dietary exposure to one mixture of pesticides was positively associated with the risk of food allergy (1.10 [1.02; 1.18]), whereas the exposure to another mixture of pesticides was positively but slightly related to the risk of wheezing (1.05 [1.01; 1.08]). This last association was not found in all sensitivity analyses. Dietary exposure to a mixture composed by perfluoroalkyl acids, PAHs and trace elements was negatively associated with the risk of asthma (0.89 [0.80; 0.99]), this association was consistent across sensitivity analyses, except the complete-case analysis.

CONCLUSION

Whereas few individual chemicals were related to the risk of allergic and respiratory diseases, some consistent associations were found between prenatal dietary exposure to some mixtures of chemicals and the risk of allergic or respiratory diseases. The positive association between trace elements, furans and PAHs and the risk of eczema, and that between pesticides mixtures and food allergy need to be confirmed in other studies. Conversely, the negative association between perfluoroalkyl acids, PAHs and trace elements and the risk of asthma need to be further explored.

Immune signatures predicting the clinical outcome of peanut oral immunotherapy: where we stand

Peanut allergy is a growing health concern that can cause mild to severe anaphylaxis as well as reduced quality of life in patients and their families. Oral immunotherapy is an important therapeutic intervention that aims to reshape the immune system toward a higher threshold dose reactivity and sustained unresponsiveness in some patients. From an immunological point of view, young patients, especially those under 3 years old, seem to have the best chance for therapy success. To date, surrogate markers for therapy duration and response are evasive. We provide a comprehensive overview of the current literature state regarding immune signatures evolving over the course of oral immunotherapy as well as baseline immune conditions prior to the initiation of treatment. Although research comparing clinical and immune traits in the first years of life vs. later stages across different age groups is limited, promising insights are available on immunological endotypes among peanut-allergic patients. The available data call for continued research to fill in gaps in knowledge, possibly in an integrated manner, to design novel precision health approaches for advanced therapeutic interventions in peanut allergy.

Complementary feeding practices are related to the risk of food allergy in the ELFE cohort

BACKGROUND

Conflicting results have been obtained when analyzing the relationship between complementary feeding (CF) practices and allergic diseases in childhood. This study aims to further explore the association between allergic diseases in early childhood (10.1016/j.jaci.2012.02.036) and the age at CF introduction (10.1016/S0140-6736(15)00149-X), food diversity in the first year of life (10.1016/j.ijporl.2019.109759) and the delayed introduction of major allergenic foods.

METHODS

This analysis focused on 6662 children from the French nationwide ELFE cohort. Data on feeding practices were collected monthly from 3 to 10 months old. Their age at CF introduction was calculated alongside a diversity score, and the number of major allergenic foods (out of eggs, fish, wheat, and dairy products) not introduced at 8 and 10 months. Their associations with parent-reported allergy-related health events between 1 and 5.5 years were assessed using logistic regressions adjusted for confounding factors. A sensitivity analysis excluding early allergic cases (occurring between 2 months and 1 or 2 years) was conducted.

RESULTS

Late CF (>6 months) was related to a higher risk of food allergy (OR [95% CI] = 1.35 [1.02; 1.78]), a low diversity score at 8 months to a higher risk of asthma (OR [95% CI] = 1.22 [1.01; 1.48]), and two allergenic foods or more not being introduced at 10 months to a higher risk of rhinoconjunctivitis (OR [95% CI] = 1.20 [1.00; 1.44]) and food allergy (OR [95% CI] = 2.46 [1.77; 3.42]). Only this last association remained significant after the exclusion of early cases.

CONCLUSION

The delayed introduction of major allergenic foods is related to a higher risk of food allergy, which supports the updated guidelines for allergy prevention.

Phase 3 Trial of Epicutaneous Immunotherapy in Toddlers with Peanut Allergy

BACKGROUND

No approved treatment for peanut allergy exists for children younger than 4 years of age, and the efficacy and safety of epicutaneous immunotherapy with a peanut patch in toddlers with peanut allergy are unknown.

METHODS

We conducted this phase 3, multicenter, double-blind, randomized, placebo-controlled trial involving children 1 to 3 years of age with peanut allergy confirmed by a double-blind, placebo-controlled food challenge. Patients who had an eliciting dose (the dose necessary to elicit an allergic reaction) of 300 mg or less of peanut protein were assigned in a 2:1 ratio to receive epicutaneous immunotherapy delivered by means of a peanut patch (intervention group) or to receive placebo administered daily for 12 months. The primary end point was a treatment response as measured by the eliciting dose of peanut protein at 12 months. Safety was assessed according to the occurrence of adverse events during the use of the peanut patch or placebo.

RESULTS

Of the 362 patients who underwent randomization, 84.8% completed the trial. The primary efficacy end point result was observed in 67.0% of children in the intervention group as compared with 33.5% of those in the placebo group (risk difference, 33.4 percentage points; 95% confidence interval, 22.4 to 44.5; P<0.001). Adverse events that occurred during the use of the intervention or placebo, irrespective of relatedness, were observed in 100% of the patients in the intervention group and 99.2% in the placebo group. Serious adverse events occurred in 8.6% of the patients in the intervention group and 2.5% of those in the placebo group; anaphylaxis occurred in 7.8% and 3.4%, respectively. Serious treatment-related adverse events occurred in 0.4% of patients in the intervention group and none in the placebo group. Treatment-related anaphylaxis occurred in 1.6% in the intervention group and none in the placebo group.

CONCLUSIONS

In this trial involving children 1 to 3 years of age with peanut allergy, epicutaneous immunotherapy for 12 months was superior to placebo in desensitizing children to peanuts and increasing the peanut dose that triggered allergic symptoms. (Funded by DBV Technologies; EPITOPE ClinicalTrials.gov number, NCT03211247.).

Continuous Rather Than Solely Early Farm Exposure Protects From Hay Fever Development

BACKGROUND

An important window of opportunity for early-life exposures has been proposed for the development of atopic eczema and asthma.

OBJECTIVE

However, it is unknown whether hay fever with a peak incidence around late school age to adolescence is similarly determined very early in life.

METHODS

In the Protection against Allergy-Study in Rural Environments (PASTURE) birth cohort potentially relevant exposures such as farm milk consumption and exposure to animal sheds were assessed at multiple time points from infancy to age 10.5 years and classified by repeated measure latent class analyses (n = 769). Fecal samples at ages 2 and 12 months were sequenced by 16S rRNA. Hay fever was defined by parent-reported symptoms and/or physician's diagnosis of hay fever in the last 12 months using questionnaires at 10.5 years.

RESULTS

Farm children had half the risk of hay fever at 10.5 years (adjusted odds ratio [aOR] 0.50; 95% CI 0.31-0.79) than that of nonfarm children. Whereas early life events such as gut microbiome richness at 12 months (aOR 0.66; 95% CI 0.46-0.96) and exposure to animal sheds in the first 3 years of life (aOR 0.26; 95% CI 0.06-1.15) were determinants of hay fever, the continuous consumption of farm milk from infancy up to school age was necessary to exert the protective effect (aOR 0.35; 95% CI 0.17-0.72).

CONCLUSIONS

While early life events determine the risk of subsequent hay fever, continuous exposure is necessary to achieve protection. These findings argue against the notion that only early life exposures set long-lasting trajectories.

Global hypomethylation in childhood asthma identified by genome-wide DNA-methylation sequencing preferentially affects enhancer regions

BACKGROUND

Childhood asthma is a result of a complex interaction of genetic and environmental components causing epigenetic and immune dysregulation, airway inflammation and impaired lung function. Although different microarray based EWAS studies have been conducted, the impact of epigenetic regulation in asthma development is still widely unknown. We have therefore applied unbiased whole genome bisulfite sequencing (WGBS) to characterize global DNA-methylation profiles of asthmatic children compared to healthy controls.

METHODS

Peripheral blood samples of 40 asthmatic and 42 control children aged 5-15 years from three birth cohorts were sequenced together with paired cord blood samples. Identified differentially methylated regions (DMRs) were categorized in genotype-associated, cell-type-dependent, or prenatally primed. Network analysis and subsequent natural language processing of DMR-associated genes was complemented by targeted analysis of functional translation of epigenetic regulation on the transcriptional and protein level.

RESULTS

In total, 158 DMRs were identified in asthmatic children compared to controls of which 37% were related to the eosinophil content. A global hypomethylation was identified affecting predominantly enhancer regions and regulating key immune genes such as IL4, IL5RA, and EPX. These DMRs were confirmed in n = 267 samples and could be linked to aberrant gene expression. Out of the 158 DMRs identified in the established phenotype, 56 were perturbed already at birth and linked, at least in part, to prenatal influences such as tobacco smoke exposure or phthalate exposure.

CONCLUSION

This is the first epigenetic study based on whole genome sequencing to identify marked dysregulation of enhancer regions as a hallmark of childhood asthma.

Fatal and near-fatal anaphylaxis: The Allergy-Vigilance® Network data (2002-2020)

BACKGROUND

Having a better understanding of the risk factors of severe anaphylaxis is a crucial challenge for physicians.

METHODS

To retrospectively analyse fatal/near-fatal anaphylaxis cases recorded by the Allergy-Vigilance® Network (2002-2020) and evaluate the characteristics associated with survival, age and allergens.

RESULTS

Among the 3510 anaphylaxis cases documented in the network, 70 (2%) patients (males: 57%; mean age: 35.4 y) presented grade 4 (Ring-Messmer) anaphylaxis and 25 died (19 food-related); 33% had a history of asthma. The main allergens were food (60%; peanut, 20%; milks, 11%) involved in 25/26 cases in children and in 17/44 (39%) cases in adults. Non-food anaphylaxis was related to drugs/latex (24%; neuromuscular blocking agents, 10%; betalactamins, 6%), Hymenoptera (16%). Three food-related cases (one death) occurred during oral food challenge in children. Patients with a food allergy were younger (22.2 years vs. 55 years, p < .001), had more likely a history of asthma (50% vs. 7%; p < .001), a pre-existing allergy (62% vs. 18%; p < .001) compared with other allergies. A cofactor was identified in 35 cases (50%) but predominantly in adults as opposed to children (64% vs. 27%; p = .01). The patients who died were younger (25.6 vs. 40.8 years; p = .01) than the survivors and mostly presented bronchospasm (56% vs. 29%; p = .05). Gaps in the prevention and management of anaphylaxis were noted in 15 cases (21%).

CONCLUSIONS

Severe food anaphylaxis has specific features compared with other causes such as young age, asthma history and exercise. Food is also involved in severe anaphylaxis in adults that should not be underestimated.

Prevalence of Food Allergy in France up to 5.5 Years of Age: Results from the ELFE Cohort

Background: In France, updated data on food allergies (FAs) are lacking, despite the need for efficient FA management and prevention. This study aimed to evaluate the prevalence of FAs in children in France, describe the most common allergens and determine the prevalence of atopic diseases in children with FAs. Methods: The ELFE study comprises a French nationwide birth cohort, including 18,329 children born in 2011. FAs were assessed by parental reports of food avoidance based on medical advice related to FAs, provided at 2 months and 2, 3.5 and 5.5 years of age. Data regarding FAs were available for 16,400 children. Data were weighted to account for selection and attrition bias. Results: From birth to 5.5 years of age, FAs were reported for 5.94% (95% CI: 5.54–6.34) children. Milk was the most common allergen, followed by egg, peanut, exotic fruits, tree nuts, gluten and fish. Among children with FAs, 20.5% had an allergy to at least two different groups of allergens; 71% reported eczema at least once before 5.5 years of age; 24.4% reported incidence of asthma; and 42.3% reported incidence of allergic rhinitis or conjunctivitis. Conclusion: In France, the prevalence of FAs in children up to 5.5 years of age is approximately 6%. It was demonstrated that 1 in 5 children with allergies had multiple FAs.

Relevance of sensitization to legumes in peanut-allergic children

BACKGROUND

Legume consumption has increased during the two past decades. In France, legumes are responsible for 14.6% of food-related anaphylaxis in children, with peanut as the main allergen (77.5%). Few studies have demonstrated cross-reactivities between peanut and other legumes. The aim of this study was to determine prevalence and relevance of sensitization to legumes in peanut-allergic children.

METHODS

All children, aged of 1-17 years, admitted to the Pediatric Allergy Department of the University Hospital of Nancy between January 1, 2017 and February 29, 2020 with a confirmed peanut allergy (PA) and a documented consumption or sensitization to at least one other legume were included. Data were retrospectively collected regarding history of consumption, skin prick tests, specific immunoglobulin E (IgE), prior allergic reactions, and oral food challenges for each legume.

RESULTS

Among the 195 included children with PA, 122 were sensitized to at least one other legume (63.9%). Main sensitizations were for fenugreek (N = 61, 66.3%), lentil (N = 38, 42.2%), soy (N = 61, 39.9%), and lupine (N = 63, 34.2%). Among the 122 sensitized children, allergy to at least one legume was confirmed for 34 children (27.9%), including six children who had multiple legume allergies (4.9%). Lentil, lupine, and pea were the main responsible allergens. Half of allergic reactions to legumes other than peanut were severe.

CONCLUSION

The high prevalence of legume sensitization and the frequent severe reactions reported in children with PA highlight that tolerated legume consumption should be explored for each legume in the case of PA, and sensitization should be investigated if not.

OUP accepted manuscript

BACKGROUND

An increasing number of infant and follow-on formulas are enriched with probiotics and/or prebiotics; however, evidence for health effects of such enrichment in early childhood remains inconclusive.

OBJECTIVES

The present study aimed to assess whether the consumption of formula enriched with probiotics or prebiotics was associated with the risk of infection and allergic diseases in early childhood.

METHODS

Analyses involved data for 8389 formula-fed children from the Etude Longitudinale Française depuis l'Enfance (ELFE) cohort. Enrichment of the formula with probiotics or prebiotics that was consumed from the age of 2-10 mo was identified by the formula ingredient list. Lower respiratory tract infection (LRTI), upper respiratory tract infection (URTI), gastrointestinal infection, wheezing, asthma, food allergy, and itchy rash were prospectively reported by parents up to the age of 5.5 y. Adjusted logistic regression models were used to assess associations between the consumption of enriched formula and risk of infection and allergic diseases.

RESULTS

Aged 2 mo, more than half of formula-fed infants consumed the probiotic-enriched formula and only 1 in 10 consumed the prebiotic-enriched formula. Consumption of the Bifidobacterium lactis-enriched formula at 2 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.84 (0.73-0.96)]. Consumption of the Bifidobacterium breve-enriched formula up to 6 mo was associated with a higher risk of LRTI [OR (95% CI) = 1.75 (1.29-2.38)] and asthma [OR (95% CI) = 1.95 (1.28-2.97)], whereas its consumption from 6 to 10 mo was associated with a lower risk of LRTI [OR (95% CI) = 0.64 (0.48-0.86)] and asthma [OR (95% CI) = 0.59 (0.40-0.88)]. Moreover, the consumption of Streptococcus thermophilus from 6 to 10 mo was associated with a higher risk of asthma [OR (95% CI) = 1.84 (1.29-2.63)]. No significant association was found for gastrointestinal infection, food allergy, and itchy rash. Overall, the consumption of prebiotic-enriched formula was not significantly associated with infection and allergy risk.

CONCLUSIONS

Associations between the consumption of probiotic-enriched formula and risk of respiratory symptoms differ according to the strain considered and consumption period. Further well-designed studies are needed to confirm these results.

Primary prevention of food allergy in 2021: Update and proposals of French-speaking pediatric allergists

During the past years, there has been an alarming increase in cases of food allergy and anaphylaxis in ever-younger children. Often, these children have multiple food allergies and food sensitizations, involving allergens with high anaphylactic potential, such as peanuts and nuts, which have a major influence on their quality of life and future. After reviewing the current epidemiological data, we discuss the main causes of the increase in food allergies. We analyze data from studies on the skin barrier and its fundamental role in the development of sensitization and food allergies, data on the tolerogenic digestive tract applied in particular to hen eggs and peanuts, as well as data on the prevention of allergy to cow milk proteins. In light of these studies, we propose a practical guide of recommendations focused on infants and the introduction of cow milk, the management of eczema, and early and broad dietary diversification including high-risk food allergens, such as peanut and nuts while taking into account the food consumption habits of the family.

Immune Responsiveness to LPS Determines Risk of Childhood Wheeze and Asthma in 17q21 Risk Allele Carriers

BACKGROUND

In murine models microbial exposures induce protection from experimental allergic asthma through innate immunity. Our aim was to assess the association of early life innate immunity with the development of asthma in children at risk.

METHODS

In the PASTURE farm birth cohort innate, Th2, Th1 and Th17 cytokine expression at age 1 year was measured after stimulation of PBMCs with lipopolysaccharide (LPS) in N=445 children. Children at risk of asthma were defined based on single-nucleotide polymorphisms at the 17q21 asthma gene locus. Specifically, we used the SNP rs7216389 in the GSDMB gene. Wheeze in the 1st year of life was assessed by weekly diaries and asthma by questionnaire at age 6 years.

RESULTS

Not all cytokines were detectable in all children after LPS-stimulation. When classifying detectability of cytokines by latent class analysis, carrying the 17q21 risk allele rs7216389 was associated with risk of wheeze only in the class with the lowest level of LPS-induced activation, odds ratio (OR)=1.89, 95%-CI 1.13-3.16, p=0.015. In contrast, in children with high cytokine activation after LPS-stimulation no association of the 17q21 risk allele with wheeze (OR=0.63, 95%-CI 0.29-1.40, p=0.258, p=0.034 for interaction) or school age asthma was observed. In these children consumption of unprocessed cow's milk was associated with higher cytokine activation (OR=3.37, 95%-CI 1.56-7.30, p=0.002), which was in part mediated by the gut microbiome.

CONCLUSIONS

These findings suggest that within the 17q21 genotype asthma risk can be mitigated by activated immune responses after innate stimulation, which is partly mediated by a gut-immune axis.

Organic Food Consumption During the Complementary Feeding Period and Respiratory or Allergic Diseases Up to Age 5.5 Years in the ELFE Cohort

Objectives: To assess (1) whether a history of allergy is associated with feeding with organic foods (OFs) during the complementary feeding period and (2) whether OF consumption in infancy is related to the incidence of respiratory and allergic diseases up to age 5.5 years.

Study Design: Analyses involved more than 8,000 children from the nationwide Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort. Associations between family or infant history of allergy and frequency of OF consumption during the complementary feeding period were assessed with multinomial logistic regression. Associations between OF consumption in infancy and respiratory or allergic diseases between age 1 and 5.5 years were assessed with logistic regression.

Results: A family history of allergy or cow's milk protein allergy at age 2 months was strongly and positively related to feeding with OF during the complementary feeding period. Feeding with OF during the complementary feeding period was not related to respiratory diseases or eczema up to age 5.5 years. Compared to infrequent consumption of both organic and commercial complementary foods, frequent OF consumption without commercial complementary foods was associated with a higher risk of food allergy, whereas frequent commercial complementary food consumption without OF use was associated with a lower risk of food allergy.

Conclusions: This study suggests that a history of allergy strongly affects feeding with OF during the complementary feeding period. However, OF consumption was not associated with reduced odds of food allergy later in childhood but could be associated with increased odds, which should be examined more deeply.

Inverse associations between food diversity in the second year of life and allergic diseases

BACKGROUND

The influence of diet in early childhood on later allergic diseases is currently a highly debated research topic. We and others have suggested that an increased diet diversity in the first year of life has a protective effect on the development of allergic diseases.

OBJECTIVE

This follow-up study aimed to investigate associations between diet in the second year of life and later allergic diseases.

METHODS

A total of 1014 children from rural areas in 5 European countries (the Protection against Allergy: Study in Rural Environments or PASTURE birth cohort) were included. Information on feeding practices in their second year of life and allergic diseases were collected up to age 6 years. Multivariate logistic regressions were performed with different models considering reverse causality, such as excluding children with a positive sensitization to egg and those with a positive sensitization to cow's milk at the age of 1 year.

RESULTS

An increased food diversity score during the second year of life was negatively associated with the development of asthma. Consumption of dairy products and eggs in the second year of life found an inverse association with reported allergic outcomes. Consumption of butter was strongly associated with protection against asthma and food sensitization. Egg was inversely associated with atopic dermatitis (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.04-0.77). Yogurt and cow's milk were inversely associated with food allergy (OR for yogurt, 0.05; 95% CI, 0.01-0.55; OR for cow's milk, 0.31; 95% CI, 0.11-0.89).

CONCLUSION

Increased food diversity in the second year of life is inversely associated with the development of asthma, and consumption of dairy products might have a protective effect on allergic diseases.

Excessive Unbalanced Meat Consumption in the First Year of Life Increases Asthma Risk in the PASTURE and LUKAS2 Birth Cohorts

A higher diversity of food items introduced in the first year of life has been inversely related to subsequent development of asthma. In the current analysis, we applied latent class analysis (LCA) to systematically assess feeding patterns and to relate them to asthma risk at school age. PASTURE (N=1133) and LUKAS2 (N=228) are prospective birth cohort studies designed to evaluate protective and risk factors for atopic diseases, including dietary patterns. Feeding practices were reported by parents in monthly diaries between the 4^th and 12^th month of life. For 17 common food items parents indicated frequency of feeding during the last 4 weeks in 4 categories. The resulting 153 ordinal variables were entered in a LCA. The intestinal microbiome was assessed at the age of 12 months by 16S rRNA sequencing. Data on feeding practice with at least one reported time point was available in 1042 of the 1133 recruited children. Best LCA model fit was achieved by the 4-class solution. One class showed an elevated risk of asthma at age 6 as compared to the other classes (adjusted odds ratio (aOR): 8.47, 95% CI 2.52–28.56, p = 0.001) and was characterized by daily meat consumption and rare consumption of milk and yoghurt. A refined LCA restricted to meat, milk, and yoghurt confirmed the asthma risk effect of a particular class in PASTURE and independently in LUKAS2, which we thus termed unbalanced meat consumption (UMC). The effect of UMC was particularly strong for non-atopic asthma and asthma irrespectively of early bronchitis (aOR: 17.0, 95% CI 5.2–56.1, p < 0.001). UMC fostered growth of iron scavenging bacteria such as Acinetobacter (aOR: 1.28, 95% CI 1.00-1.63, p = 0.048), which was also related to asthma (aOR: 1.55, 95% CI 1.18-2.03, p = 0.001). When reconstructing bacterial metabolic pathways from 16S rRNA sequencing data, biosynthesis of siderophore group nonribosomal peptides emerged as top hit (aOR: 1.58, 95% CI 1.13-2.19, p = 0.007). By a data-driven approach we found a pattern of overly meat consumption at the expense of other protein sources to confer risk of asthma. Microbiome analysis of fecal samples pointed towards overgrowth of iron-dependent bacteria and bacterial iron metabolism as a potential explanation.

Predictive factors of allergy to pistachio in children allergic to cashew nut

BACKGROUND

Cashew nut (CN) allergy prevalence has increased over the last few years. In children allergic to CN, complete avoidance of pistachio is usually recommended, but recent study showed that only one third of children allergic to CN were also allergic to pistachio. The aim of our study was to identify predictive factors of allergy to pistachio in children allergic to CN.

METHODS

All children who had a positive oral food challenge (OFC) to CN between November 2013 and October 2017 in the Paediatric Allergy Department of the University Hospital of Nancy were included. Logistic regression models were used to predict the probability of allergy to pistachio.

RESULTS

Among the 147 children included, tolerance or allergy to pistachio was known for 51. Out of these, 40 were allergic to pistachio (78.4%). Children allergic to pistachio had a larger weal size of skin prick test to CN (P = .01) and pistachio (P = .0007) and a lower reaction dose to CN (P < .0001). In multivariate analysis, only the reaction dose to CN was significantly associated with allergy to pistachio. Children with a low reaction dose to CN were significantly more at risk to have an allergy to pistachio (P = .01).

CONCLUSION

A low reaction dose to CN seems to be a predictive factor of allergy to pistachio in children allergic to CN. In order to limit unnecessary food eviction, a pistachio OFC should be performed in children having high reaction dose whatever the importance of the skin or the specific IgE sensitization to pistachio.

[Diagnosis of allergy in asthma]

Allergy is a hypersensitivity reaction induced by immunological mechanisms. In asthma, allergy has a complex role and is usually IgE mediated. Allergy must be evaluated during the work up but evidence of IgE sensitivity does not mean that allergens play a role in the pathophysiology of the disease. The clinical relevance of the sensitivity has to be considered. This paper describes current available tools to screen for IgE sensitivity, allergen exposure and their role in asthma.

Parents know it best: Prediction of asthma and lung function by parental perception of early wheezing episodes

BACKGROUND

Childhood asthma is often preceded by early wheeze. Usually, wheezing episodes are recorded retrospectively, which may induce recall bias.

AIMS AND OBJECTIVES

The aim of this study was to investigate true-positive recall of parent-reported wheeze at 1 year of age, its determinants, and its implications for asthma and lung function at 6 years of age.

METHODS

The PASTURE (Protection Against Allergy-Study in Rural Environments) study followed 880 children from rural areas in 5 European countries from birth to age 6 years. Wheeze symptoms in the first year were asked weekly. At age 6, parent-reported asthma diagnosis was ascertained and lung function measurements were conducted. Correct parental recall of wheeze episodes at the end of the first year was assessed for associations with lung function, asthma, and the asthma risk locus on chromosome 17q21.

RESULTS

Parents correctly recalled wheeze after the first year in 54% of wheezers. This true-positive recall was determined by number of episodes, timing of the last wheeze episode, and parental asthma. Independently from these determinants, true-positive recall predicted asthma at age 6 years (odds ratio 4.54, 95% confidence interval (CI) [1.75-14.16]) and impaired lung function (β = -0.62, 95% CI [-1.12; -0.13], P-value = .02). Associations were stronger in children with asthma risk SNPs on chromosome 17q21.

CONCLUSION

Correct parental recall of wheezing episodes may reflect clinical relevance of early wheeze and its impact on subsequent asthma and lung function impairment. Questions tailored to parental perception of wheezing episodes may further enhance asthma prediction.

Use of partially hydrolysed formula in infancy and incidence of eczema, respiratory symptoms or food allergies in toddlers from the ELFE cohort

BACKGROUND AND OBJECTIVES

Partially hydrolyzed formulas (pHF) are recommended in non-breastfed infants with familial history of allergy to prevent allergy development. However, recent meta-analysis does not provide strong support for their protective effect. The present work assesses the links between 2-month infant formula use and the incidence of eczema, respiratory symptoms, or food allergies (FA) up to 2 years of age.

METHODS

The nationwide ELFE birth cohort is a population-based study from mainland France. Infant feeding (breast milk only, partially hydrolyzed formula with [pHF-HA] or without a hypoallergenic label [pHF-non-HA], and non-hydrolyzed formula [Nhf]) was reported at 2 months. Eczema, FA, and respiratory symptoms such as wheezing and asthma were reported at 2 months, 1 year, and 2 years. Infants with prior FA at 2 months were excluded from analyses.

RESULTS

Among 11 720 infants, those who received only breast milk at 2 months were at lower risk of eczema at 1 year than those who received nHF (OR[95% CI] = 0.78[0.65-0.94] in non-at-risk infants; 0.86[0.75-0.98] in at-risk infants). The use of pHF-HA, compared with nHF, at 2 months was related to higher risk of wheezing at 1 year in at-risk infants (1.68[1.24-2.28]) and higher risk of FA at 2 years both in non-at-risk infants (3.78[1.52-9.41]) and in at-risk infants (2.31[1.36-3.94]).

CONCLUSIONS

In this nationwide study, pHF-HA use was not associated with a lower risk of any of the studied outcomes. Quite the reverse, it was associated with a higher risk of wheezing and FA. This should be confirmed in further studies.

Breastfeeding Status and Duration and Infections, Hospitalizations for Infections, and Antibiotic Use in the First Two Years of Life in the ELFE Cohort

In low- and middle-income countries, the protective effect of breastfeeding against infections is well established, but in high-income countries, the effect could be weakened by higher hygienic conditions. We aimed to examine the association between breastfeeding and infections in the first 2 years of life, in a high-income country with relatively short breastfeeding duration. Among 10,349 young children from the nationwide Etude Longitudinale Française depuis l’Enfance (ELFE) birth cohort, breastfeeding and parent-reported hospitalizations, bronchiolitis and otitis events, and antibiotic use were prospectively collected up to 2 years. Never-breastfed infants were used as reference group. Any breastfeeding for <3 months was associated with higher risks of hospitalizations from gastrointestinal infections or fever. Predominant breastfeeding for <1 month was associated with higher risk of a single hospital admission while predominant breastfeeding for ≥3 months was associated with a lower risk of long duration (≥4 nights) of hospitalization. Ever breastfeeding was associated with lower risk of antibiotic use. This study confirmed the well-known associations between breastfeeding and hospitalizations but also highlighted a strong inverse association between breastfeeding and antibiotic use. Although we cannot infer causality from this observational study, this finding is worth highlighting in a context of rising concern regarding antibiotic resistance.

Association between antibiotic treatment during pregnancy and infancy and the development of allergic diseases

BACKGROUND

Allergies are a serious public health issue, and prevalences are rising worldwide. The role of antibiotics in the development of allergies has repeatedly been discussed, as results remain inconsistent. The aim of this study was to investigate the association between pre- and post-natal antibiotic exposure and subsequent development of allergies (atopic dermatitis, food allergy, asthma, atopic sensitization and allergic rhinitis).

METHODS

A total of 1080 children who participated in a European birth cohort study (PASTURE) were included in this analysis. Data on antibiotic exposure during pregnancy and/or first year of life and allergic diseases were collected by questionnaires from pregnancy up to 6 years of age and analysed by performing logistic regressions. To take into account reverse causation, we included models, where children with diagnosis or symptoms of the respective disease in the first year of life were excluded.

RESULTS

Antibiotic exposure in utero was significantly and positively associated with atopic dermatitis and food allergy. The strongest effect was on diseases with onset within the first year of life (for atopic dermatitis: aOR 1.66, 95% CI 1.11-2.48 and for food allergy: aOR 3.01, 95% CI 1.22-7.47). Antibiotics in the first year of life were positively associated with atopic dermatitis up to 4 years (aOR 2.73, 95% CI 1.66-4.49) and also suggested a dose-response relationship. A tendency was observed with asthma between 3 and 6 years (aOR 1.65, 95% CI 0.95-2.86).

CONCLUSIONS

Our findings show positive associations between exposure to antibiotics and allergies, mainly atopic dermatitis and food allergy within the first year of life, after prenatal exposure, and atopic dermatitis and asthma after post-natal exposure to antibiotics in children born in rural settings.