Early-life predictors and risk factors of peanut allergy, and its association with asthma in later-life: Population-based birth cohort study

Trajectories of egg sensitization in childhood: Two birth cohorts in Asia and Europe

BACKGROUND

Hen's egg exposure through impaired skin barrier is considered a major mechanism of sensitization to eggs. However, the impact of filaggrin (FLG) gene loss-of-function mutations on the natural history of egg sensitization lacks consensus among studies.

OBJECTIVE

To evaluate the association between the natural course of egg sensitization and FLG mutations.

METHODS

We used Japanese and the UK birth cohorts (CHIBA and MAAS) to identify the longitudinal patterns of egg sensitization until mid-school age and examined the relationship between the identified patterns and FLG mutations. Sensitization was assessed using egg white-specific IgE levels or skin prick tests (SPTs). Egg allergy was confirmed by parental reports and sensitization. Latent class growth analysis identified longitudinal patterns.

RESULTS

Three similar patterns of egg sensitization (persistent, early-onset remitting, and no/low grade classes) were identified in both cohorts, with differing prevalence estimates. The proportion of children with egg allergy in the persistent class at 7 or 8 years of age was 23% (CHIBA) and 20% (MAAS). Consistently in both cohorts, FLG mutations were significantly associated only with the persistent class. Children with FLG mutations had an approximately four-fold increased risk of being in the persistent sensitization class (RRRs: 4.3, 95%C.I. (1.2-16.0), p = .03 in CHIBA; 4.3 (1.3-14.7), p = .02 in MAAS).

CONCLUSION

FLG loss-of-function mutations are associated with persistent egg sensitization in both Japanese and European ethnicities, and the mutations might be a potential biomarker for identifying the risk of persistent egg sensitization/allergy in early infancy. Future studies should incorporate oral food challenges to confirm this relationship.

Health Promotion of Early and Sustained Allergenic Food Introduction for the Prevention of Food Allergy

Observational studies and landmark randomized control trials support early and sustained allergenic food introduction in infancy as an effective preventive strategy against food allergy development. Despite a consensus regarding the intended goals of early and sustained allergenic food introduction, there have been myriad policy recommendations among health authorities in how to achieve both individual and population-level health outcomes for food allergy prevention. This clinical management review provides an overview on the data that informs early and sustained allergenic food introduction strategies, suggestions on how to advise allergenic food introduction, principles of prevention programs as they relate to food allergy prevention, and health promotion and systems-level challenges that impede achievement of food allergy prevention goals.

Understanding the heterogeneity of childhood allergic sensitization and its relationship with asthma

PURPOSE OF REVIEW

To review the current state of knowledge on the relationship between allergic sensitization and asthma; to lay out a roadmap for the development of IgE biomarkers that differentiate, in individual sensitized patients, whether their sensitization is important for current or future asthma symptoms, or has little or no relevance to the disease.

RECENT FINDINGS

The evidence on the relationship between sensitization and asthma suggests that some subtypes of allergic sensitization are not associated with asthma symptoms, whilst others are pathologic. Interaction patterns between IgE antibodies to individual allergenic molecules on component-resolved diagnostics (CRD) multiplex arrays might be hallmarks by which different sensitization subtypes relevant to asthma can be distinguished. These different subtypes of sensitization are associated amongst sensitized individuals at all ages, with different clinical presentations (no disease, asthma as a single disease, and allergic multimorbidity); amongst sensitized preschool children with and without lower airway symptoms, with different risk of subsequent asthma development; and amongst sensitized patients with asthma, with differing levels of asthma severity.

SUMMARY

The use of machine learning-based methodologies on complex CRD data can help us to design better diagnostic tools to help practising physicians differentiate between benign and clinically important sensitization.

Peanut Allergy and Component-Resolved Diagnostics Possibilities-What Are the Benefits?

Peanut allergy is a widespread and potentially life-threatening condition that affects both children and adults, with a growing incidence worldwide. It is estimated to affect around 1-2% of the population in several developed countries. Component-resolved diagnostics is a modern approach to allergy diagnosis that focuses on identifying specific allergenic proteins to provide precise diagnoses and personalized treatment plans. It is a technique that enables the analysis of specific IgE antibodies against tightly defined molecules (components) that constitute the allergen. Component-resolved diagnostics is particularly valuable in peanut allergy diagnosis, helping to determine allergen components associated with severe reactions. It also aids in predicting the course of the allergy and enables the development of personalized immunotherapy plans; however, the full application of it for these purposes still requires more precise studies. In this paper, we present the current knowledge about peanut allergy and component-resolved diagnostics possibilities. We discuss the possibilities of using molecular diagnostics in the diagnosis of peanut allergy. We focus on examining and predicting the development of peanut allergy, including the risk of anaphylaxis, and describe the latest data related to desensitization to peanuts.

Development of peanut, sesame and tree nut allergy in Polish children at high risk of food allergy: a protocol for a cross-sectional study

INTRODUCTION

Peanut allergies cause serious health problems worldwide. A strong finding has shown that the early introduction of peanuts into the diet of infants at high risk of food allergy reduces the prevalence of peanut allergy. Allergies to peanuts, sesame and tree nuts have been shown to coexist in 60% of cases and vary according to geographical location and dietary habits. Insights into the prevalence of nut and seed allergies in societies with varying consumption levels are essential for developing population-specific weaning guidelines. Understanding the age at which peanut allergy develops is paramount for successful early introduction strategies.

METHODS AND ANALYSIS

We will perform a cross-sectional study at two tertiary allergy centres in Warsaw and Bydgoszcz. Two hundred forty children aged 4-36 months with eczema or egg allergy will undergo an extensive assessment of their peanut, sesame and tree nut allergy status through skin testing, specific IgE measurements and oral food challenges. The primary outcome is the prevalence of peanut, sesame and tree nut allergies in Polish children at high risk of food allergy. Additionally, the timing of the development of peanut, sesame and tree nut allergies in the first 3 years of life in a high-risk population will be assessed.

ETHICS AND DISSEMINATION

The Ethics Committee of the Medical University of Warsaw, Poland approved this protocol (KB/86/2021). The results of this study will be submitted to a peer-reviewed journal no later than 1 year after data collection. The abstract will be presented at relevant national and international conferences.Although the authors may be able to commit to journal submission no later than 1 year after data collection, publication dates remain beyond their control.

TRIAL REGISTRATION NUMBER

NCT05662800.

Infant food allergy phenotypes and association with lung function deficits and asthma at age 6 years: a population-based, prospective cohort study in Australia

BACKGROUND

Food allergy is considered a precursor to asthma in the context of the atopic march, but the relationship between infant food allergy phenotypes and lung function and asthma in childhood is unclear. We aimed to examine the association between food sensitisation and challenge-confirmed food allergy in infancy, as well as persistent and resolved food allergy up to age 6 years, and the risk of lung function deficits and asthma at age 6 years.

METHODS

The longitudinal, population-based HealthNuts cohort study in Melbourne, VIC, Australia, recruited 5276 infants children aged 1 year who attended council-run immunisation sessions between Sept 28, 2007, and Aug 5, 2011. At age 1 year, all children completed skin prick testing to four food allergens (egg, peanut, sesame, and either shrimp or cow's milk) and an oral food challenge (egg, peanut, and sesame) at the Royal Children's Hospital in Melbourne. Parents completed questionnaires about their infant's allergy history, demographic characteristics, and environmental exposures. At age 6 years, children were invited for a health assessment that included skin prick testing for ten foods (milk, egg, peanut, wheat, sesame, soy, shrimp, cashew, almond, and hazelnut) and eight aeroallergens (alternaria, cladasporum, house dust mite, cat hair, dog hair, bermuda grass, rye grass, and birch mix), oral food challenges, and lung function testing by spirometry. Questionnaires completed by parents (different to those completed at age 1 year) captured the child's allergy and respiratory history and demographics. We investigated associations between food allergy phenotypes (food-sensitised tolerance or food allergy; and ever, transient, persistent, or late-onset food allergy), lung function spirometry measures (forced expiratory volume in 1 sec [FEV1] and forced vital capacity [FVC] z-scores, FEV1/FVC ratio, forced expiratory flow at 25% and 75% of the pulmonary volume [FEF25-75%], and bronchodilator responsiveness), and asthma using regression methods. Only children with complete data on the exposure, outcome, and confounders were included in models. Infants without food sensitisation or food allergy at age 1 year and 6 years served as the reference group.

FINDINGS

Of 5276 participants, 3233 completed the health assessment at age 6 years and were included in this analysis. Food allergy, but not food-sensitised tolerance, at age 1 year was associated with reduced FEV1 and FVC (aβ -0·19 [95% CI -0·32 to -0·06] and -0·17 [-0·31 to -0·04], respectively) at age 6 years. Transient egg allergy was associated with reduced FEV1 and FVC compared with never having egg allergy (-0·18 [95% CI -0·33 to -0·03] and -0·15 [-0·31 to 0·00], respectively), whereas persistent egg allergy was not (FEV1 -0·09 [-0·48 to 0·31]; FVC -0·20 [-0·62 to 0·21]). Transient peanut allergy was associated with reduced FEV1 and FVC (FEV1 aβ -0·37 [-0·79 to 0·04] and FVC aβ -0·55 [-0·98 to -0·12]), in addition to persistent peanut allergy (FEV1 aβ -0·30 [-0·54 to -0·06] and FVC aβ-0·30 [-0·55 to -0·05]), and late-onset peanut allergy (FEV1 aβ -0·62 [-1·06 to -0·18] and FVC aβ-0·49 [-0·96 to -0·03]). Estimates suggested that food-sensitised tolerance and food allergy were associated with reduced FEF25-75%, although some estimates were imprecise. Food allergy phenotypes were not associated with an FEV1/FVC ratio. Late-onset peanut allergy was the only allergy phenotype that was possibly associated with increased risk of bronchodilator responsiveness (2·95 [95% CI 0·77 to 11·38]). 430 (13·7%) of 3135 children were diagnosed with asthma before age 6 years (95% CI 12·5-15·0). Both food-sensitised tolerance and food allergy at age 1 year were associated with increased asthma risk at age 6 years (adjusted odds ratio 1·97 [95% CI 1·23 to 3·15] and 3·69 [2·81 to 4·85], respectively). Persistent and late-onset peanut allergy were associated with higher asthma risk (3·87 [2·39 to 6·26] and 5·06 [2·15 to 11·90], respectively).

INTERPRETATION

Food allergy in infancy, whether it resolves or not, is associated with lung function deficits and asthma at age 6 years. Follow-up studies of interventions to prevent food allergy present an opportunity to examine whether preventing these food allergies improves respiratory health.

FUNDING

National Health & Medical Research Council of Australia, Ilhan Food Allergy Foundation, AnaphylaxiStop, the Charles and Sylvia Viertel Medical Research Foundation, the Victorian Government's Operational Infrastructure Support Program.

Risk Factors for Anaphylaxis in Children Allergic to Peanuts

Background and Objectives: A peanut allergy is the most common single cause of anaphylaxis in children. The risk factors for anaphylaxis in children with a peanut allergy are not well defined. Therefore, we aimed to identify epidemiological, clinical, and laboratory characteristics of children with a peanut allergy that may predict the severity of the allergic reaction and anaphylaxis. Materials and Methods: We conducted a cross-sectional study and included 94 children with a peanut allergy. Allergy testing was performed, including skin prick testing and the determination of specific IgE levels to peanuts and their Ara h2 component. In case of discordance between patient history and allergy testing, an oral food challenge with peanuts was performed. Results: Anaphylaxis and moderate and mild reactions to peanuts occurred in 33 (35.1%), 30 (31.9%), and 31 (33.0%) patients, respectively. The severity of the allergic reaction was only weakly correlated (p = 0.04) with the amount of peanuts consumed. The median number of allergic reactions to peanuts was 2 in children with anaphylaxis compared to 1 in other patients (p = 0.04). The median level of specific IgE to Ara h2 was 5.3 IU/mL in children with anaphylaxis compared to 0.6 IU/mL and 10.3 IU/mL in children with mild and moderate peanut allergies (p = 0.06). The optimal cutoff for distinguishing between anaphylaxis and a less severe allergic reaction to peanuts was a specific IgE Ara h2 level of 0.92 IU/mL with 90% sensitivity and 47.5% specificity for predicting anaphylaxis (p = 0.04). Conclusions: Epidemiological and clinical characteristics of the patient cannot predict the severity of the allergic reaction to peanuts in children. Even standard allergy testing, including component diagnostics, is a relatively poor predictor of the severity of an allergic reaction to peanuts. Therefore, more accurate predictive models, including new diagnostic tools, are needed to reduce the need for oral food challenge in most patients.

Vegan diets from an allergy point of view - Position paper of the DGAKI working group on food allergy

Vegan diets are currently attracting a great deal of attention. However, avoiding animal-based foods restricts the diet and is associated with risks, the extent and medical implications of which are at present not sufficiently understood. Elimination diets represent the usual therapeutic long-term management in the presence of food allergy. In order to understand the risks of vegan diets and to discuss these critically from the perspective of food allergies, the expertise of a nutritionist/dietitian with expertise in this area is indispensable. This position paper deals with the incentives behind and the benefits of a plant-based diet. The knowledge required to cover macro- and micronutrient dietary requirements is presented. Using the avoidance of cow's milk as an example, the challenges of adequately meeting nutritional needs are identified and (so-called) milk alternatives are evaluated from an allergy and nutritional point of view. Finally, other plant-based (substitute) products are evaluated from the same perspective, as significant protein sources in vegan diets (e.g., legumes, nuts, and seeds) are at the same time potential and potent triggers of allergic reactions. However, the allergic potential of many substitute products cannot be fully assessed at present due to gaps in research. Wheat as the most important trigger for anaphylaxis in adults is also evaluated. Finally, the increase in ultra-processed products in the (vegan) food sector and their potential consequences for the immune system are discussed.

Oral immunotherapy using boiled peanuts for treating peanut allergy: An open-label, single-arm trial

BACKGROUND

Peanut allergy affects 1%-3% of children in Western countries. Boiling peanuts has been demonstrated to result in a hypoallergenic product that may provide a safer way of inducing desensitization in peanut-allergic patients by first inducing tolerance to boiled peanut. We aimed to assess the efficacy and safety of oral immunotherapy (OIT) using sequential doses of boiled peanuts followed by roasted peanuts for treating peanut allergy in children.

METHODS

In this open-label, phase 2, single-arm clinical trial, children aged 6-18 years with a positive history of peanut allergy and positive peanut skin prick test ≥ 8 mm and/or peanut-specific IgE ≥ 15 kU/L at screening underwent OIT involving sequential up-dosing with 12-hour boiled peanut for 12 weeks, 2-hour boiled peanut for 20 weeks and roasted peanut for 20 weeks, to a target maintenance dose of 12 roasted peanuts daily.

PRIMARY OUTCOME

proportion of children passing open-label oral food challenge involving cumulative administration of 12 roasted peanuts (12 g peanuts; approximately 3000 mg peanut protein) 6-8 weeks after reaching the target maintenance dose. Secondary outcomes included treatment-related adverse events and use of medications for treating allergy symptoms.

RESULTS

Between 1 July 2017 and 22 June 2018, 70 participants were enrolled and commenced OIT. Desensitization was successfully induced in 56 of 70 (80%) participants. Withdrawal due to treatment-related adverse events was infrequent (n = 3). Treatment-related adverse events were reported in 43 (61%) participants, corresponding to a rate of 6.58 per 1000 OIT doses. Medication use associated with treatment-related adverse events was infrequent, with rescue epinephrine use reported by three (4%) participants (0.05 per 1000 doses).

CONCLUSION

Oral immunotherapy using boiled followed by roasted peanuts represents a pragmatic approach that appears effective in inducing desensitization and is associated with a favourable safety profile.

Effects of regular soy formula intake between 1 and 2 months of age on food sensitization in infancy

BACKGROUND

The effects of regular soy formula (SF) intake on the development of food sensitization in infancy remain unclear. This study aimed to assess the effects of regular SF intake between 1 and 2 months of age on food sensitization development by 6 months of age.

METHODS

Using data from a randomized controlled trial of a birth cohort from four Japanese hospitals that assessed cow's milk allergy development, we performed a retrospective cohort study of 235 infants who avoided cow's milk formula and supplemented breastfeeding with SF as required between 1 and 2 months of age. Regular SF intake was defined as SF consumption of ≥14 days per month and ≥1350 ml per month. Food sensitization was defined as positive skin prick test reactions to hen's egg, cow's milk, wheat, and/or soy. Using multivariable logistic regression models that adjusted for parental, perinatal, and environmental factors, we calculated the adjusted odds ratios of regular SF intake for food, hen's egg, and cow's milk sensitization by 6 months of age.

RESULTS

From the 235 participants, 114 (48.5%) had regular SF intake. The adjusted odds ratios of regular SF intake for food, hen's egg, and cow's milk sensitization were 0.32 (95% confidence interval: 0.16-0.62, p = .0007), 0.42 (0.20-0.88, p = .02), and 0.33 (0.14-0.81, p = .02), respectively.

CONCLUSION

Regular SF intake between 1 and 2 months of age in infants avoiding cow's milk formula was significantly associated with a reduced risk of food sensitization in infancy.

Preventing allergies through the skin

OBJECTIVE

To inform readers of the current and forthcoming skin barrier interventions that have clinically relevant implications in the prevention of allergic sensitization and atopic diseases.

DATA SOURCES

Peer-reviewed journal articles indexed on PubMed and clinical trials referenced on clinicaltrials.gov were analyzed.

STUDY SELECTIONS

Literature searches from PubMed and clinicaltrials.gov were performed using combinations of the following search terms: prevention, allergy, atopy, skin, cutaneous, microbiome, microbiota, Staphylococcus aureus, atopic dermatitis, eczema, food allergy, and asthma.

RESULTS

The skin barrier represents an entry point for allergic sensitization and T_H2-mediated allergic disorders. Results from clinical trials designed to improve microbiome complexity and reduce S aureus colonization, provide skin barrier enhancement, and deliver epicutaneous immunotherapy are summarized and discussed in the context of primary, secondary, and tertiary prevention of allergic disease.

CONCLUSION

The skin barrier is a promising target for prevention of allergic disease, though clinical trial results thus far have been mixed, at best.