Time trends of childhood food allergy in China: Three cross-sectional surveys in 1999, 2009, and 2019

Prevention of Food Allergy: Harmonizing Perspectives from the East and West

BACKGROUND

The global epidemiology of food allergies and anaphylaxis exhibits complex, heterogeneous patterns. While food allergy prevalence has stabilized in Western countries, anaphylaxis incidence continues to rise. In developing regions, data are limited, but urban centers show increasing food allergy prevalence, contrasting with lower rates in rural areas. These disparities likely stem from differences in environmental factors and urbanization levels across the globe. Furthermore, the dominant food allergens vary significantly by regions. Peanuts and tree nuts are the primary triggers in the USA and Europe, whereas eggs, milk, and shellfish are more common in Asia and Latin America.

SUMMARY

In this upcoming review, we will delve into the recommendations for preventing food allergies across Eastern and Western regions. These regional differences in allergen profiles and dietary patterns underscore the need for tailored food allergy prevention strategies. Current prevention guidelines focus on the timing and route of allergen exposure in early life. In high-prevalence regions, early oral exposure is recommended to promote oral tolerance and reduce allergy risk. Conversely, in lower-prevalence areas, non-delayed introduction of allergenic solids is preferred. Moreover, early skin exposure may increase allergy risk, and the role of early, whole-body use of specialized emollients requires further study. Proactive treatment of atopic dermatitis may reduce the incidence of food allergies in infants. Adapting prevention approaches to local contexts and continuously updating guidelines based on emerging evidence is crucial to comprehensively addressing the global burden of food allergies.

Research Progress of Oral Immune Tolerance Mechanism Induced by Whey Protein

Cow milk allergy (CMA) is prevalently observed among infants and young children, exerting adverse effects on their growth and quality of life. Oral immune tolerance (OIT) is a more effective method for the prevention and treatment of CMA. The site of OIT is mainly in the gastrointestinal tract, so this article reviews the composition and structural characteristics of intestinal immune system, the molecular mechanisms of immune tolerance by regulatory T cells (Treg), dendritic cells, and gut microbiota. In addition, this paper summarizes the research progress of T cell epitope peptides of β-lactoglobulin and α-lactalbumin in whey protein hydrolysates. The mechanism of OIT induced by whey protein hydrolysate or whey protein combined with other anti-allergic components (phenolic compounds, probiotics, etc.) is overviewed to provide new ideas for the development of hypoallergenic infant formula.

Effects of allergic diseases on social-emotional development in children at 12 months of age: A Prospective Cohort Study

OBJECTIVES

The link between allergic diseases and deficits in children's neurodevelopment has been suggested, but it remains unclear regarding the allergy-related effects on social-emotional development in early life. Our study aimed to explore the association between allergic diseases and social-emotional development during infancy using a prospective study.

METHODS

937 infants at 6 months were recruited from two community hospitals in Shanghai, of which 805 infants followed up at 12 months. The outcome was social-emotional concern, defined by Ages & Stages Questionnaire: Social-Emotional and personal social domain from Ages & Stages Questionnaire with established cutoffs. Allergic diseases were assessed using modified International Study of Asthma and Allergies in Childhood core questionnaire. Allergy patterns were classified based on time of onset and persistence as "Never", "Transient" (allergy at age of 0-6 months only or 7-12 months only), "Persistent" (allergy at age of 0-6 and 7-12 months).

RESULTS

8.45 % of 12-month infants exhibited social-emotional concerns. Infants had increased risk of social-emotional concerns at 12 months who suffered allergic diseases during 0-12 months (adjusted odd ratio [aOR], 2.22; 95 % confidence interval [CI], 1.33-3.70), 7-12 months (aOR[95%CI]: 2.07 [1.21, 3.57]) and 0-6 months (aOR[95%CI]: 1.90 [1.12, 3.21]). Additionally, infants with persistent allergy had a 161 % higher risk of social-emotional concern (aOR[95%CI]: 2.61 [1.29, 5.28], P = 0.008) compared to infants without allergy (P for trend = 0.001).

CONCLUSION

Allergic infants were more likely to experience social-emotional concerns, particularly for those with persistent allergy. To optimize social-emotional development, we highlight regular monitoring of mental health and effective management of allergy during infancy.

Dietary AGEs and food allergy: insights into the mechanisms of AGEs-induced food allergy and mitigation strategies

Food allergy (FA) is a significant public health concern, with over one billion individuals globally affected, and its prevalence continues to rise. Advanced glycation end products (AGEs) are common hazards in various diet. Recent investigations have shown that AGEs could influence the pathogenesis of FA by interacting with AGEs receptors. This paper provides a comprehensive review of recent advances on diet AGEs, summarized the mechanisms of AGEs in regulating food allergy and mitigation strategies, analyzed the limitations of current research on AGEs and prospected the future research. AGEs could combine with the receptors for AGEs (RAGE) to induce oxidative stress, inflammation and allergic signaling pathways. AGEs can affect allergen epitopes and conformation and regulate intestinal flora in a non-receptor-dependent manner, as well as affect the intestinal barrier and Th1/Th2 immune balance through receptor-dependent pathways to regulate food allergy. Currently, the approaches to reduce the AGEs-induced food allergy mainly depended on improving food processing methods (e.g., low temperature, short time, low pH and non-thermal processing methods), natural AGEs inhibitors and RAGE inhibitors. This review elucidates the influences of AGEs on food allergy and mitigation strategies, which could provide novel insights into reducing food allergy induced by diet AGEs.

Early Origins of Asthma and Allergies: Clues From Studies in China

Asthma and allergies have emerged as some of the most common chronic diseases, particularly in developed countries. Epidemiological studies have consistently demonstrated that children growing up in farming/rural environments are less likely to develop these conditions. Over the past three decades, China has experienced unprecedented economic development and urbanisation, accompanied by a rapid rise in the prevalence of allergic disorders. Despite the substantial number of affected individuals, allergy management in China remains inconsistent and often inadequate, compounded by variations in diagnostic criteria and limited healthcare access in less developed regions. Furthermore, the vast population, regional disparities, and methodological inconsistencies in data collection have hindered the acquisition of comprehensive, large-scale epidemiological data. This review examines the factors contributing to asthma and allergies from their early origins, focusing on modifiable factors from a specific perspective of China. Factors related to traditional lifestyle, such as early-life exposure to agricultural farming and poultry, diverse dietary patterns, and early introduction of allergenic foods, appear to offer protection against allergies. Conversely, exposure to open-fire cooking, incense burning, tobacco smoke, as well as early-life antibiotic use and perinatal factors like Caesarean section delivery and prematurity may represent potential risks. A clear understanding of the role of these factors would pave the way for developing effective interventions to mitigate the substantial health and socioeconomic burdens associated with asthma and allergies.

The Relationship Between Dietary Patterns and the Epidemiology of Food Allergy

Food allergies are increasing globally, particularly in Asia; however, the etiologies of allergic diseases remain poorly understood despite comprehensive studies conducted across a variety of populations. Epidemiological research demonstrates that food allergy is more prevalent in Westernized or urbanized societies than in rural or developing ones. As such, comparing the distribution and patterns of food allergies as well as the environmental exposures between regions may provide insight into potential causal and protective factors of food allergy. Diet is an important exposome that has been shown to modulate the immune system both directly and indirectly via pathways involving the microbiota. Changes in dietary patterns, especially the shift to a Westernized diet with reduced dietary fiber and an abundance of processed foods, impact the gut and skin epithelial barrier and contribute to the development of chronic inflammatory diseases, such as food allergy. Although dietary intervention is believed to have tremendous potential as a strategy to promote immunological health, it is essential to recognize that diet is only one of many factors that have changed in urbanized societies. Other factors, such as pollution, microplastics, the use of medications like antibiotics, and exposure to biodiversity and animals, may also play significant roles, and further research is needed to determine which exposures are most critical for the development of food allergies.

Exploring geographical variances in component-resolved diagnosis within the Asia-Pacific region

Component-resolved diagnostics (CRD) have revolutionized allergy diagnosis, offering enhanced accuracy and insights into allergen sensitization patterns. This review explores geographical variances in CRD for food and aeroallergens across the Asia-Pacific region. We examine the varying prevalence of allergic diseases and the utility of CRD in diagnosing common food allergies, including peanut, shellfish, fish, wheat, and fruits. Notable differences in serum-specific (sp)IgE sensitization patterns and the clinical relevance of particular allergen components are observed between populations in Asian countries and those in Europe and the United States. For food allergies, the literature reports significant differences in allergen components and their diagnostic utility across various countries. Peanut allergy diagnostics, particularly Ara h 2 spIgE, show varying sensitivity and specificity between Asian and Western populations. In shellfish allergy, emerging allergens beyond tropomyosin are gaining importance in the Asia-Pacific region. Fish and wheat allergies also demonstrate unique sensitization patterns, emphasizing the need for region-specific diagnostic approaches. Regarding aeroallergens, pollen sensitization profiles vary widely across the region, influenced by local flora and climate, to influence symptoms of pollen food allergy syndrome. House dust mite allergens remain a significant concern, with high sensitization rates to major components like Der p 1, Der p 2, and the emerging Der p 23. The cross-reactivity between house dust mite and shellfish allergens is particularly relevant in this region. These findings emphasize the need for region-specific CRD approaches, considering local allergen profiles and sensitization patterns. As the prevalence of allergic diseases continues to rise in the Asia-Pacific, further research into locally relevant allergens and their components is crucial for improving diagnosis, patient management, and targeted immunotherapy strategies in this diverse region.

Oral Exposure to Clostridium difficile Toxin A Aggravates Food Allergy by Intestinal Barrier Destruction, Mast Cell Activation, and Th2-Biased Immune Responses

Food allergy is a complex disease, with multiple environmental factors involved. Considering the regulatory effect of Clostridium difficile toxin A (Tcd A) on biological processes of allergic reactions, the role of oral exposure to Tcd A on food allergy was investigated. The intestinal permeability and β-hexosaminidase were promoted by Tcd A using the in vitro Caco-2 and HT-29 cells coculture monolayer and bone marrow-derived mast cell (MCs) degranulation model. When the sensitized mice were challenged with OVA and 4 μg of Tcd A, specific IgE and MCPT-1 levels were increased. The results of flow cytometry and ELISA demonstrated that the Th1 and Treg cells were reduced and higher IL-5 was induced. The jejunum staining showed that villus injury and MC accumulation were aggravated. All of the findings demonstrated that Tcd A could aggravate food allergy, and the orally exposed risk factors aggravating food allergy warrant increasing attention.

Optimizing β-Lactoglobulin antigenicity through single enzyme hydrolysis: Exploring structural changes and effects on linear epitopes

β-lactoglobulin (β-LG) is the major allergen in dairy products, but research on the optimal conditions for antigen reduction in β-LG using different enzymes remains limited. Therefore, this study aims to investigate the antigenicity, structural characteristics, and peptide distribution of advantageous protease hydrolysates capable of eliminating the allergenic epitopes of β-LG selected via bioinformatics tools. The results showed that under optimal enzymatic hydrolysis conditions, the antigen reduction rates for the four advantageous proteases acting on β-LG were 47.37 % (pepsin), 33.54 % (chymotrypsin A), 38.71 % (papain), and 45.91 % (stem bromelain), respectively. The four proteases effectively degraded β-LG, causing shorter peptide chain formation, reduced content of highly ordered α-helix, decreased fluorescence intensity, and lower surface hydrophobicity. Furthermore, they cleaved the linear epitopes of β-LG into peptides of varying sizes, leading to different antigen reduction rates among the hydrolysates. These findings provide a theoretical basis for developing targeted enzymatic hydrolysis technologies and low-allergenicity dairy-based materials.

Oral exposure to ovalbumin alters glucose metabolism in sensitized mice: upregulation of HIF-1α-mediated glycolysis

Food allergies are pathological adverse reactions against harmless dietary proteins. While studies have shown the involvement of host metabolic changes (e.g., lipid metabolism and amino acid metabolism) in the development of food allergy (FA), the adaptive changes in glucose metabolism induced by food allergen exposure remain largely unclear. In this study, BALB/c mice were sensitized intraperitoneally with an ovalbumin (OVA)/aluminum adjuvant, followed by oral OVA challenges to induce anaphylaxis. Increased levels of serum OVA-specific IgE and MCPT-1, and Th2 response bias were also presented in FA mice. Subsequently, the intestinal untargeted metabolomic analysis revealed the signature enrichment of glycolysis, manifested by increases in glycolytic metabolites including glucose-6-phosphate, fructose-6-phosphate, 2-phosphoglycerate, and lactate in FA mice. Consistently, the serum lactate level was found to be significantly elevated in allergic mice. Oral administration of OVA also upregulated the expression of critical metabolic enzymes in glycolysis, namely hexokinase 2, phosphoglycerate mutase 1, and lactate dehydrogenase. Moreover, the hypoxia inducible factor-1 (HIF-1) signaling pathway was activated in FA mice, and the expression of HIF-1α, known as the upstream regulator of glycolysis, was increased after oral OVA challenges. In vitro inhibition of HIF-1α was found to impede mast cell inflammatory responses to allergens. In summary, this study demonstrated that OVA-induced FA exhibited a glucose metabolic feature of HIF-1α-mediated glycolysis upregulation, suggesting the potential of HIF-1α/glycolysis targeted strategies in the alleviation of FA.

Food Allergy in Children in China

The prevalence of food allergies in China seems to be increasing, but there are limited studies describing the pattern of food allergies across the country. This review highlights regional variations observed across China, with data indicating a higher prevalence in the more economically developed eastern and southern coastal regions compared to inland areas. Egg and milk are the most common allergies among children under 3 years old; for children above 3 years old, specific food allergens also show regional differences, with shellfish allergies being more common in southern and eastern coastal areas, while wheat and fruit allergies are more prevalent in northern regions. Emerging peanut and tree nut allergies have also been observed in China's megacities, although the prevalence remains relatively low compared to Western countries. These geographic and environmental influences highlight the complexity of the food allergy landscape in China and the need for a more nuanced understanding of the underlying drivers. Despite the growing burden of food allergies, significant gaps exist in effectively managing these conditions in China. Lack of standardised diagnostic tools, limited access to oral food challenges and a shortage of trained allergists pose major challenges. Another critical gap is the limited availability and affordability of epinephrine autoinjectors, essential for managing life-threatening anaphylactic reactions. Addressing these systemic deficiencies in China's food allergy management infrastructure will require concerted efforts from policymakers, healthcare systems and pharmaceutical companies. Investing in the development of standardised diagnostics, expanding the allergy speciality workforce and ensuring equitable access to emergency care and treatment options are crucial steps towards improving health outcomes for the millions of individuals affected by food allergies in China.

Next-generation reference interval for total IgE in the United States: A retrospective real-world analysis

OBJECTIVE

To establish a next-generation reference interval (RI) for total IgE (tIgE) and evaluate its usefulness.

METHODS

A new allergen-specific IgE (sIgE)-based tIgE RI, including a continuous RI in children, was established using the NHANES 2005-2006 project. The usefulness of the RI was evaluated by sensitivity (Sen), specificity (Spec), positive predictive value (PPV), negative predictive value (NPV), κ coefficient and consistency.

RESULTS

The new tIgE RI showed better performance in identifying allergic sensitization (Sen 0.53, Spec 0.90, PPV 0.83, NPV 0.68, κ 0.44, consistency 0.72) than allergic diseases (Sen 0.37, Spec 0.75, PPV 0.55, NPV 0.60, κ 0.13, consistency 0.59). The 2014 U.S. tIgE RI was more effective in identifying allergic diseases (consistency 0.63 vs. 0.54, P<0.001) but less accurate in identifying allergic sensitization (consistency 0.59 vs. 0.67, P<0.001) in children than in adults. The new RI improved the accuracy of identifying allergic sensitization in children to a level similar to that in adults (consistency 0.72 vs 0.73, P=0.37) and maintained its advantage in identifying allergic diseases in children (consistency 0.64 vs 0.55, P<0.001).

CONCLUSIONS

The established next-generation tIgE RI is useful for identifying allergic sensitization, especially in children.

Food allergy in a changing dietary landscape: A focus on the Asia Pacific region

Recent studies have provided compelling evidence to suggest that various environmental factors play a significant role in the development of food allergies. As our society experiences rapid economic growth, increased urbanization, and a shift towards a more Westernized diet, the incidence of food allergies is also on the rise and the pattern is gradually evolving. This review will delve into the changes in the epidemiology of food allergies within the Asia-Pacific region and the various dietary practices and factors that are postulated to play a role in the rise in food allergies over the years. Although there have been important advancements in the field of food allergies, there are still numerous uncertainties regarding the intricate relationship between diet and food allergies. Specifically, the role of epigenetic factors in influencing the susceptibility to food allergies, as evidenced by studies that assessed the impact of migration and rural-urban dynamics, is not fully understood. Addressing this knowledge gap presents an opportunity to develop more effective prevention and treatment strategies that could greatly benefit individuals living with food allergies.

The correlation of asparaginase enzyme activity levels after PEG-asparaginase administration with clinical characteristics and adverse effects in Chinese paediatric patients with acute lymphoblastic leukaemia

Studies on asparaginase enzyme activity (AEA) monitoring in Chinese patients receiving PEG-asparaginase remain limited. We monitored AEA in paediatric patients diagnosed with acute lymphoblastic leukaemia (ALL) and treated according to the Chinese Children's Cancer Group study protocols, CCCG-ALL-2015/CCCG-ALL-2020 protocols. We measured the AEA at days 7 ± 1 and 14 ± 1 and analysed their association with patient characteristics and PEG-asparaginase-related adverse effects (AEs). We measured 2147 samples from 329 patients. Mean AEA levels (interquartile range) were 931 iu/L (654-1174 iu/L) at day 7 ± 1 and 664 iu/L (463-860 iu/L) at day 14 ± 1. The AEA levels were higher in younger children and increased with the cumulative dose numbers. PEG-asparaginase inactivation rate was 19.1%, and the silent inactivation (SI) rate was 12.5%. Nine patients were identified with allergic-like reactions. Hypofibrinogenaemia, hypertriglyceridaemia, pancreatitis and thrombosis were associated with older age, whereas hypoglycaemia was associated with younger age. The risk of hypertriglyceridaemia and hypoglycaemia increased with cumulative dose numbers of PEG-asparaginase. Except for hypofibrinogenaemia, elevated AEA levels did not increase the risk of PEG-asparaginase-related AEs. Drug monitoring can be utilized as guidance for treatment decision-making. Individualizing asparaginase doses do not reduce toxicities. The treatment target of PEG-asparaginase remains to achieve sustained and adequate activity.

A review of common influencing factors and possible mechanisms associated with allergic diseases complicating tic disorders in children

Over the past few decades, the incidence of childhood allergic diseases has increased globally, and their impact on the affected child extends beyond the allergy itself. There is evidence of an association between childhood allergic diseases and the development of neurological disorders. Several studies have shown a correlation between allergic diseases and tic disorders (TD), and allergic diseases may be an important risk factor for TD. Possible factors influencing the development of these disorders include neurotransmitter imbalance, maternal anxiety or depression, gut microbial disorders, sleep disturbances, maternal allergic status, exposure to tobacco, and environmental factors. Moreover, gut microbial disturbances, altered immunological profiles, and DNA methylation in patients with allergic diseases may be potential mechanisms contributing to the development of TD. An in-depth investigation of the relationship between allergic diseases and TD in children will be important for preventing and treating TD.

The pathogenesis of food allergy and protection offered by dietary compounds from the perspective of epigenetics

Food allergy is a global food safety concern, with an increasing prevalence in recent decades. However, the immunological and cellular mechanisms involved in allergic reactions remain incompletely understood, which impedes the development of effective prevention and treatment strategies. Current evidence supports those epigenetic modifications regulate the activation of immune cells, and their dysregulation can contribute to the development of food allergies. Patients with food allergy show epigenetic alterations that lead to the onset, duration and recovery of allergic disease. Moreover, many preclinical studies have shown that certain dietary components exert nutriepigenetic effects in changing the course of food allergies. In this review, we provide an up-to-date overview of DNA methylation, noncoding RNA and histone modification, with a focus on their connections to food allergies. Following this, we discuss the epigenetic mechanisms that regulate the activation and differentiation of innate and adapted immune cell in the context of food allergies. Subsequently, this study specifically focuses on the multidimensional epigenetic effects of dietary components in modulating the immune response, which holds promise for preventing food allergies in the future.

Combined transcriptomics and TMT-proteomics reveal abnormal complement and coagulation cascades in cow's milk protein allergy

Cow's milk protein allergy (CMPA) is primarily due to the inability of the intestinal mucosa to establish typical immunological tolerance to proteins found in cow's milk, and the specific molecular mechanism is still unclear. In order to investigate molecular alterations in intestinal tissues during CMPA occurrence, this study analyzed the jejunal tissue of β-lactoglobulin (BLG)-sensitized mice through transcriptomics and quantitative tandem mass tag (TMT)-labeled proteomics. A total of 475 differentially expressed genes (256 up-regulated, 219 down-regulated) and 94 differentially expressed proteins (65 up-regulated, 29 down-regulated) were identified. Comparing the KEGG pathways of the two groups, it was found that both were markedly enriched in the signaling pathways of complement and coagulation cascade. Among these, kallikrein B1 (KLKB1) in this pathway is speculated to be pivotal in CMPA. It may potentially enhance the release of bradykinin by activating the kallikrein-kinin system, leading to pro-inflammatory effects and exacerbating intestinal mucosal damage. This study suggests that the pathways of complement and coagulation cascades could be significant in the context of intestinal immunity in CMPA, and KLKB1 may be its potential therapeutic target.

The Natural History and Risk Factors for the Development of Food Allergies in Children and Adults

PURPOSE OF REVIEW

This narrative review explores food allergy prevalence and natural history stratified by life stages, especially in context of evolving knowledge over the last few decades.

RECENT FINDINGS

The prevalence of food allergy remains highest in early childhood with common food triggers being cow's milk, soy, hen's egg, wheat, peanut, tree nuts, sesame, fish, and shellfish. This correlates with certain risk factors especially pertinent in the postnatal period which appear to predispose an individual to developing a food allergy. Some allergies (such as milk and egg) were previously thought to be easily outgrown in early life; however, recent studies suggest increasing rates of persistence of these allergies into young adulthood; the reason behind this is unknown. Despite this, there is also evidence demonstrating that food allergies can be outgrown in adolescents and adults. An understanding of the paradigm shifts in the natural history of food allergy allows clinicians to provide updated, age-appropriate, and tailored advice for patients on the management and prognosis of food allergy.

Comparison of cow's milk allergy models highlighted higher humoral and Th2 immune responses in BALB/c than C3H/HeNCrl mice

Cow's milk allergy (CMA) is common in early childhood and the incidence is increasing. However, its mechanisms of action are still not fully understood due to the range of different clinical symptoms. So far, the development of different mouse models has been the best choice to study the molecular mechanisms triggering allergy. However, the selection of suitable strains for the establishment of animal models truly representative of associated human pathologies is still a challenge. Hence, we focused on both C3H/HeNCrl and BALB/c mice to characterize their susceptibility to CMA. After intraperitoneal sensitization, BALB/c and C3H/HeNCrl strains were challenged with β-lactoglobulin (BLG), and compared in allergic symptoms and active immune response, which assessed by specific antibody production and cytokine release. At first, both groups exhibited anaphylaxis, showed specific BLG-related IgE, Th2 response and seemed both suitable for the development of CMA models. However, a detailed analysis revealed that BALB/c had both stronger humoral and Th2 immune responses, producing more antibodies (IgE and IgG/IgG1/IgG2a), and releasing higher levels of Th2-associated cytokines (IL-4, IL-5, IL-13) compared to C3H/HeNCrl mice. Therefore, BALB/c strain would represent a preferential choice in the establishment of CMA models. This study highlights the subtle differences and major outcomes in the selection of mouse strains for the development of suitable food allergy models.

Modification of Food Allergy on the Associations between Early Life Exposure to Size-Specific Particulate Matter and Childhood Allergic Rhinitis

Previous studies have reported the association between particulate matter (PM) and childhood allergic rhinitis (AR). However, it is unclear whether food allergy (FA) modifies the PM-AR association. We aimed at evaluating the effect of the modification of FA on PM-AR association in preschool children. We adopted a cross-sectional study and conducted a questionnaire survey among preschool children aged 3-6 years in 7 cities in China from June 2019 to June 2020 to collect information on AR and FA. We used a combination of multilevel logistic regression and restricted cubic spline functions to quantitatively assess whether FA modifies the associations between size-specific PM exposure (1 × 1 km) and the risk of AR. The adjusted odds ratios (ORs) for AR among the children with FA as per a 10 μg/m3 increase in early life PM1, PM2.5, and PM10 were significantly higher than the corresponding ORs among the children without FA [e.g., OR: 1.58, 95% CI: (1.32, 1.90) vs 1.29, 95% CI: (1.18, 1.41), per 10 μg/m3 increase in PM1]. The interactions between FA and size-specific PM exposure and their effects on AR were statistically significant (all p-int < 0.001). FA, as an important part of the allergic disease progression, may modify the PM-AR association in preschool children.

Allergen immunotherapy in China

Allergen immunotherapy (AIT) is an etiological treatment strategy that involves administering escalating doses of clinically relevant allergens to desensitize the immune system. It has shown encouraging results in reducing allergy symptoms and enhancing patients' quality of life. In this review, we offer a thorough overview of AIT in China, examining its efficacy, safety, current practices, and prospects. We further underscore the progress made in AIT research and clinical applications, as well as the distinct challenges and opportunities that China faces in this area.

Effect of lactic acid bacteria fermentation on cow milk allergenicity and antigenicity: A review

Cow milk is a major allergenic food. The potential prevention and treatment effects of lactic acid bacteria (LAB)-fermented dairy products on allergic symptoms have garnered considerable attention. Cow milk allergy (CMA) is mainly attributed to extracellular and/or cell envelope proteolytic enzymes with hydrolysis specificity. Numerous studies have demonstrated that LAB prevents the risk of allergies by modulating the development and regulation of the host immune system. Specifically, LAB and its effectors can enhance intestinal barrier function and affect immune cells by interfering with humoral and cellular immunity. Fermentation hydrolysis of allergenic epitopes is considered the main mechanism of reducing CMA. This article reviews the linear epitopes of allergens in cow milk and the effect of LAB on these allergens and provides insight into the means of predicting allergenic epitopes by conventional laboratory analysis methods combined with molecular simulation. Although LAB can reduce CMA in several ways, the mechanism of action remains partially clarified. Therefore, this review additionally attempts to summarize the main mechanism of LAB fermentation to provide guidance for establishing an effective preventive and treatment method for CMA and serve as a reference for the screening, research, and application of LAB-based intervention.

Molecular characterization of Clostridium perfringens isolates from a tertiary children's hospital in Guangzhou, China, establishing an association between bacterial colonization and food allergies in infants

BACKGROUND

Cow's milk protein allergy (CMPA) is one of the most common types of food allergy in infants. Faecal pathogen cultures showed that the positive rate of Clostridium perfringens was more than 30%, which was significantly higher than that for other bacteria. Therefore, it is speculated that Clostridium perfringens colonization may be one of the pathogenetic factors for CMPA in infants. We conducted a real-world evidence study. Infants aged 0-6 months with diarrhoea and mucoid and/or bloody stools were recruited from a large tertiary hospital in China. Faecal pathogen cultures for the detection of Clostridium perfringens were confirmed by flight mass spectrometry, and potential toxin genes were identified using PCR. After 12 months of follow-up, the diagnoses of CMPA and food allergy were recorded. The correlation was assessed by Pearson correlation analysis.

RESULTS

In this study, 358 infants aged 0-6 months with gastrointestinal symptoms and faecal pathogen cultures were recruited. A total of 270 (44.07% girls; mean age, 2.78 ± 2.84 months) infants were followed up for 12 months. Overall, the rate of positivity for Clostridium perfringens in faecal pathogen cultures was 35.75% (128/358) in infants aged ≤ 6 months. The earliest Clostridium perfringens colonization was detected within 2 days after birth. The majority of Clostridium perfringens isolates were classified as type C in 85 stool samples. In the Clostridium perfringens-positive group, 48.21% (54/112) of infants were clinically diagnosed with food allergies after 12 months, including 37.5% (42/112) with CMPA, which was significantly higher than that of the negative group, with 7.59% (12/158) exhibiting food allergies and 5.06% (8/158) presenting CMPA (P < 0.0001). Faecal Clostridium perfringens positivity was significantly correlated with CMPA, food allergy, faecal occult blood, faecal white blood cells, antibiotic use, increased peripheral blood platelet counts, and decreased haemoglobin levels (P < 0.0001).

CONCLUSIONS

This study demonstrates that intestinal colonization by Clostridium perfringens is common in infants. The majority of Clostridium perfringens isolates are classified as type C. Colonization of the intestine by Clostridium perfringens is associated with the development of CMPA and food allergy in infants.

Prevalence of self-reported food allergy in Tunisia: General trends and probabilistic modeling

Background

Food allergy (FA) has become a major public health concern affecting millions of children and adults worldwide. In Tunisia, published data on FA are scarce.

Methods

This study, was intended to fill the gap and estimate the frequency of allergy to different foods in the Sfax region, Tunisia, within self-reported FA. One hundred twenty-five (125) children (56% males, 1-17 years old), and 306 adults (17% males, 18-70 years old) were interviewed using a bilingual questionnaire.

Results

The number of self-reported food allergens in this sample was 105; allergens were clustered in 8 foods: fruits, seafood, eggs, milk and dairy, cereals, nuts, vegetables, and peanuts. Cutaneous reactions were the most frequent symptoms, in both children and adults. About 40% of children and 30% of adults had a family history of FA. About 81% of adults and 38% of children are allergic to at least 1 non-food allergen. The most prevalent food allergen was the fruit group in both adults and children, followed by seafood. Most food allergies were mutually exclusive and 90% of individuals have a single FA. The relationship between self-declared FA was modeled using a Bayesian network graphical model in order to estimate conditional probabilities of each FA when other FA is present.

Conclusions

Our findings suggest that the prevalence of self-reported FA in Tunisia depends on dietary habits and food availability since the most frequent allergens are from foods that are highly consumed by the Tunisian population.

Development of a Two-Step Hydrolysis Hypoallergenic Cow's Milk Formula and Evaluation of Residue Allergenicity by Peptidomics and Immunoreactivity Analysis

Cow's milk allergy (CMA) is an abnormal immune response that severely affects the nutritional supplementation of allergic infants. Currently, only a limited number of hypoallergenic formulas are available on the market, and these are only categorized according to their degree of hydrolysis, which still poses an allergy risk and cannot be consumed by CMA patients, especially infants. To address this issue, we developed a two-step hydrolysis hypoallergenic formula targeting destruction of allergen epitope from whey protein. Then, a comprehensive evaluation system was constructed, including peptidomics analysis, in vivo and in vitro allergenicity assessments, revealing allergic changes in the product from the epitope structure level to the immunological level. The results showed that 97.14% of hydrolyzed peptides from α-lactalbumin and β-lactoglobulin did not contain allergenic epitopes after treatment with trypsin and flavourzyme. In vitro and in vivo allergenicity assessment results confirmed that the two-step hydrolysis method effectively reduced the allergenicity of whey protein. Compared with the common milk powder, the hypoallergenic formula induced lower levels of basophil degranulation and relieved the body's anaphylactic symptoms caused by cow milk. This study provides a promising solution to the limited hypoallergenic formula problem and may benefit allergic infants who require nutritional supplements.

Positive rate of wheat allergens in the Chinese allergic population: a systematic review and meta-analysis

In recent years, the prevalence of allergic diseases has increased significantly, causing great concern, and wheat, as one of the top 8 food allergens, is a common allergy trigger. Nevertheless, reliable estimates of the positivity rate of wheat allergens in the allergic population in China are still lacking. The systematic review and meta-analysis aims to evaluate the positive detection rate of wheat allergens in the Chinese allergic population and further provide a reference for the prevention of allergy. CNKI, CQVIP, WAN-FANG DATA, Sino Med, PubMed, Web of Science, Cochrane Library, and Embase databases were retrieved. Related research and case reports about the positive rate of wheat allergen in the Chinese allergic population published from inception to June 30, 2022, were searched, and meta-analysis was performed using Stata software. The pooled positive rate of wheat allergens and 95% confidence interval were calculated by random effect models, and the publication bias was evaluated using Egger's test. A total of 13 articles were included for the final meta-analysis, in which wheat allergen detection methods involved only serum sIgE testing and SPT assessment. The results showed that the wheat allergen positivity detection rate in Chinese allergic patients was 7.30% (95% CI 5.68-8.92%). Subgroup analysis showed that the positivity rate of wheat allergens was influenced by region, but hardly by age and assessment method. The positive rates of wheat allergy in the population with allergic diseases were 2.74% (95% CI 0.90-4.58%) and 11.47% (95% CI 7.08-15.87%) in southern and northern China, respectively. In particular, the positive rates of wheat allergens were greater than 10% in Shaanxi, Henan and Nei Mongol, all of which belong to the northern region. These results suggest that wheat allergens are an important cause of sensitization in allergic populations from northern China, and therefore attention should be paid to early prevention in high-risk populations.

Immune regulation by fermented milk products: the role of the proteolytic system of lactic acid bacteria in the release of immunomodulatory peptides

Food allergies have emerged as a pressing health concern in recent years, largely due to food resources and environmental changes. Dairy products fermented by lactic acid bacteria play an essential role in mitigating allergic diseases. Lactic acid bacteria have been found to possess a distinctive proteolytic system comprising a cell envelope protease (CEP), transporter system, and intracellular peptidase. Studying the impact of different Lactobacillus proteolytic systems on the destruction of milk allergen epitopes and their potential to alleviate allergy symptoms by releasing peptides containing immune regulatory properties is a valuable and auspicious research approach. This paper summarizes the proteolytic systems of different species of lactic acid bacteria, especially the correlation between CEPs and the epitopes from milk allergens. Furthermore, the mechanism of immunomodulatory peptide release was also concluded. Finally, further research on the proteolytic system of lactic acid bacteria will provide additional clinical evidence for the possible treatment and/or prevention of allergic diseases with specific fermented milk/dairy products in the future.

Changes in risk factors for food sensitization in early life: Analysis over a period of 10 years

Background

Although epidemiological trends of childhood food sensitization (FS) in IgE-mediated food allergy were reported in China, few studies have examined at changes in its risk factors.

Objective

To investigate the change in early-life risk factors associated with childhood food sensitization during 2009–2019 in China.

Methods

Data from two cross-sectional surveys conducted in 2009 and 2019 (401 and 513 children, respectively) were analyzed. The results of skin prick tests and information on food sensitization-related risk factors in children were summarized, including family history of atopic disease (FHA), demographic characteristics, method of delivery, feeding patterns, sibship size, pet ownership, and vitamin D supplementation. Binary logistic regression was used to calculate the odds ratio and the regression coefficient β-value of risk factors in the 2009 and 2019 surveys separately. Then, coefficient β-value differences between the two surveys were analyzed by the bdiff command in STATA to describe the change in risk factors over 10 years.

Results

The 2009 survey revealed that FHA, age, only child, and feeding patterns were associated with food sensitization. The 2019 survey showed that food sensitization was affected by age, sex, and feeding patterns. However, from 2009 to 2019, the probability of food sensitization in the only-child group significantly increased by 226.0% (β-value difference = 0.81, P = 0.024) and decreased by 65.0% in female children (β-value difference = −1.06, P = 0.008). The effect of age on food sensitization decreased by 50.0% (β-value difference = −0.69, P &lt; 0.001) over 10 years.

Conclusion

The effect of FHA and common lifestyle factors on food sensitization did not significantly change during 2009−2019. However, the influence of demographic characteristics on food sensitization has changed since 2009; that is, older age, male gender, and only child are more likely to develop food sensitization, which needs to be considered in future epidemiological surveys.

Clinical Trial Registration

http://www.chictr.org.cn/, identifier ChiCTR1900024338.

Prevalence of parent-reported food allergy among children in China: A population-based cross-sectional survey

Objective

The prevalence of food allergy (FA) has been increasing in recent years and has become an important public health, food safety, and clinical nutrition problem. However, population-based studies on the prevalence of FA are very limited in China. This study aims to determine the prevalence and pattern of parent-reported FA among school children in Jiangxi Province, China.

Methods

A multicenter cross-sectional study on FA was conducted on primary school children aged 6-11 years old using random cluster sampling with a questionnaire survey. Parent-reported FA was used and defined as individual-reported FA by parent or guardian through a questionnaire in this study.

Result

Among the total of 8,856 (96.36%) complete questionnaires received, 727 (8.2%) children had adverse reactions to food (ARF). The prevalence rates of parent-reported FA and doctor-diagnosed FA were 6.2% and 3.3%, respectively. Animal-derived foods were the main causative source of FA, and the three leading allergenic foods were shrimp, mango, and mollusks. Skin reactions were the most common clinical manifestations of FA, accounting for 63.7%, and 45.32% of the subjects with parent-reported FA experienced severe allergic reactions. There was a significant difference in parent-reported FA between different survey centers, and FA risk increased significantly in children with other allergic diseases (P<0.001) and small family size (P=0.026). The FA prevalence was significantly higher among children aged 8-11 years than those aged 6-7 years (P=0.020).

Conclusions

A high prevalence of parent-reported FA was observed among children in general primary schools in Jiangxi Province, China. Shrimp, mango, and mollusks were the most common causative foods. The main common symptoms of FA were adverse reactions relating to the skin system. The rate of severe allergic reactions was also high in Jiangxi Children with reported FA. Local standards and policies for the prevention and management of FA need to be adjusted on a timely basis according to actual local conditions.

Multi-Perspective Observation on the Prevalence of Food Allergy in the General Chinese Population: A Meta-Analysis

Reliable estimates of the prevalence of food allergy (FA) among the general Chinese population have remained unclear. This meta-analysis aims to provide an accurate estimate of FA prevalence in China with comprehensive data. A systematic literature search was conducted in eight electronic databases, i.e., China National Knowledge Infrastructure, Wanfang, Weipu, China Biology Medicine, Web of Science, PubMed, Cochrane, and Embase. A random-effects model was used to analyze the pooled prevalence of FA for four different assessment methods. A total of 46 eligible articles were included in the narrative synthesis, and 41 articles were ultimately included in the meta-analysis. Overall, the pooled prevalence of self-reported FA, self-reported physician-diagnosed FA, SPT (specific skin prick test)-positive FA, and OFC (open food challenge)-positive FA were 11.5% (95% CI: 9.8-13.5%), 5.3% (95% CI: 4.2-6.5%), 11.6% (95% CI: 9.6-14.1%), and 6.2% (95% CI: 4.4-8.7%), respectively. Subgroup analyses suggested that the prevalence of FA was affected by age, year of data collection, region, and sample size, but not by gender. This meta-analysis indicated that FA is common among Chinese people, with an increasing trend in prevalence during the past two decades. Given the high heterogenicity between these studies, a national survey with a large sample size based on standardized diagnosis is urgently needed to gain a more scientific understanding of the actual situation of food allergy in China.

Quality and consistency of clinical practice guidelines on the prevention of food allergy and atopic dermatitis: Systematic review protocol

Background and aims

Allergy prevention strategies have gained significant traction as a means to attenuate the growing burden of allergic diseases over the past decade. As the evidence base for primary prevention of food allergy (FA) and atopic dermatitis (AD) is constantly advancing, clinical practice guideline (CPG) recommendations on interventions for FA and AD prevention vary in quality and consistency among professional organizations. We present a protocol for a systematic review of CPGs on primary prevention of FA and AD.

Methods

We will systematically review and appraise all CPGs addressing primary prevention of FA and AD and report our findings according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases and manual website searches from January 2011 to March 2021 without language or geographical restrictions, and supplemented by author contact, will generate the list of potentially relevant CPGs to screen. Evaluation of the methodological quality, consistency, and global applicability of shortlisted CPGs will be performed by members of the Allergy Prevention Work Group of the World Allergy Organization (WAO) using the Appraisal of Guidelines for Research and Evaluation (AGREE) II and AGREE-REX (Recommendations EXcellence). instruments. Guideline contents, consistency, and quality of the recommendations will be summarised in tabular and narrative formats. We aim to present consolidated recommendations from international guidelines of the highest methodological quality and applicability, as determined by AGREE II and AGREE-REX.

Dissemination

This systematic review will provide a succinct overview of the quality and consistency of recommendations across all existing CPGs for FA and AD prevention, as well as crucial perspectives on applicability of individual recommendations in different geographical contexts. Results from this systematic review will be reported in a peer-reviewed journal. It will also inform a position statement by WAO to provide a practical framework to guide the development of future guidelines for allergy prevention worldwide.

Prospero registration number

CRD42021265689.

Investigation of the Mechanism of 60Co Gamma-Ray Irradiation-Stimulated Oxidation Enhancing the Antigenicity of Ovalbumin by High-Resolution Mass Spectrometry

⁶⁰Co gamma-ray irradiation-induced antigenicity changes in ovalbumin (OVA) were investigated, and the molecular mechanism was analyzed. Irradiation treatment at 0-100 kGy could significantly enhance the IgG/IgE binding ability of OVA in a dose-dependent paradigm by concomitant oxidative modification, which exhibited color browning and an increase in carbonyl content caused by high-penetrable rays. More allergenic epitopes of OVA were exposed after irradiation treatment reflected by structural changes including the unfolding of tertiary structure, the conversion of α-helix structures to β-sheet and random coil structures, and the cleavage of several peptide bonds. Meanwhile, three oxidation sites of K46, T49, and N260 located in key linear epitopes were observed, which might increase the allergenic ability of OVA via the disaggregation of noncovalent bonds and the unwinding of α-helix structures. Conclusively, irradiation may enhance the potential allergenicity of OVA by oxidative modification, which provides theoretical guidance for effectively controlling the oxidation of proteins in the irradiation process.

Trends in use of specialised formula for managing cow's milk allergy in young children

BACKGROUND

Excessive use of specialised formula for cow's milk allergy was reported in England, but complete analysis has not been undertaken and trends in other countries are unknown. Some specialised formula products, especially amino-acid formula, have high free sugars content. We evaluated specialised formula trends in countries with public databases documenting national prescription rates.

METHODS

Cross-sectional analysis of national prescription databases in United Kingdom, Norway and Australia. Outcomes were volume and cost of specialised formula, and proportion of infants prescribed specialised formula. Expected volumes assumed 1% cow's milk allergy incidence and similar formula feeding rates between infants with and without milk allergy.

RESULTS

Prescribed volumes of specialised formula for infants rose 2.8-fold in England from 2007-2018, with similar trends in other regions of the United Kingdom. Volumes rose 2.2-fold in Norway from 2009-2020 and 3.2-fold in Australia from 2001-2012. In 2020, total volumes were 9.7 to 12.6-fold greater than expected in England, 8.3 to 15.6-fold greater than expected in Norway and 3.3 to 4.5-fold greater than expected in Australia, where prescribing restrictions were introduced in 2012. In Norway the proportion of infants prescribed specialised formula increased from 2.2% in 2009 to 6.9% in 2020, or 11.2 to 13.3-fold greater than expected. In 2020, specialised formula for infants cost US$117 (103 euro) per birth in England, US$93 (82 euro) in Norway and US$27 (23 euro) in Australia. Soya formula prescriptions exceeded expected volumes 5.5 to 6.4-fold in England in 1994 and subsequently declined, co-incident with public health concerns regarding soya formula safety. In 2020, 30-50% of prescribed specialised formula across the three countries was amino-acid formula.

CONCLUSIONS

In England, Norway and Australia, specialised formula prescriptions increased in the early 21^st century and exceeded expected levels. Unnecessary specialised formula use may make a significant contribution to free sugars consumption in young children.

IgE-Mediated food allergy: Current diagnostic modalities and novel biomarkers with robust potential

Food allergy (FA) is a serious public health issue afflicting millions of people globally, with an estimated prevalence ranging from 1-10%. Management of FA is challenging due to overly restrictive diets and the lack of diagnostic approaches with high accuracy and prediction. Although measurement of serum-specific antibodies combined with patient medical history and skin prick test is a useful diagnostic tool, it is still an imprecise predictor of clinical reactivity with a high false-positive rate. The double-blind placebo-controlled food challenge represents the gold standard for FA diagnosis; however, it requires large healthcare and involves the risk of acute onset of allergic reactions. Improvement in our understanding of the molecular mechanism underlying allergic disease pathology, development of omics-based methods, and advances in bioinformatics have boosted the generation of a number of robust diagnostic biomarkers of FA. In this review, we discuss how traditional diagnostic modalities guide appropriate diagnosis and management of FA in clinical practice, as well as uncover the potential of the latest biomarkers for the diagnosis, monitoring, and prediction of FA. We also raise perspectives for precise and targeted medical intervention to fill the gap in the diagnosis of FA.

Trends in the contributions of atopic family history to pediatric food sensitization and allergy

OBJECTIVE

Family history of atopic diseases (FHA) contributes to food allergy (FA). But little is known whether FHA primarily increases IgE-mediated, non-IgE-mediated FA, or both. And the trends in the contributions of FHA to food sensitization (FS) and FA remain unclear. We aim to clarify the associations among FHA, FS and FA and to understand the trends in the contributions of FHA to FS and FA.

METHODS

We used chi-square test and mediating effect model to analyze the associations among FHA, FS and FA through comparisons between two cross-sectional investigations on FA in children under 2 years old in 2009 and 2019.

RESULTS

In 2009 and 2019, the positive FHA proportion tended to be increasing without significance (28.9% to 31.6%, P = 0.39). Subgroup analysis showed the FS rate in FA group decreased significantly (37/39 to 44/62, P = 0.003). In 2009, the FS rate and FA prevalence were higher in FHA (+) group than in FHA (-) group (26% vs. 14.7%, P = 0.008 and 15% vs. 7.7%, P = 0.03), and FS had a complete mediating effect on the association between FHA and FA (Z = 2.54, P = 0.011), but the results lost significance in 2019.

CONCLUSIONS

The association between FHA and FA was completely mediated by FS, which means FHA mainly increases IgE-mediated FA. And the contributions of FHA to FS and FA tended to be stabilized or even diminished, which means FHA alone could no longer be enough to screen high-risk children.

The prevalence and temporal trends of food allergy among preschool children in Northern Thailand between 2010 and 2019

Background

Although recent studies suggest that the prevalence of food allergy (FA) has not changed, the data from developing countries are limited. This study aimed to investigate time trends in the prevalence of FA among preschool children in 2010 and 2019 in Northern Thailand.

Methods

Two cross-sectional studies were performed, 9 years apart (2010 and 2019), using the same methods, in children aged 3–7 years living in Chiang Mai, Thailand. Parent-reporting questionnaire surveys were conducted. Families with children reporting FA were invited to undergo further investigations with skin prick testing, serum specific IgE, and oral food challenge (OFC). The prevalence of parent-reported FA, food sensitization, and OFC-confirmed FA were compared between the 2 periods.

Results

A total of 1013 out of 1146 questionnaires (452/546 in 2010 and 561/600 in 2019) were returned. The response rate was 88.4%. The prevalence of parent-reported food allergy in 2019 was significantly lower than that in 2010 (5.5% vs 9.3%; p = 0.02). However, there was no significant change in the prevalence of OFC-confirmed FA (0.9% vs 1.1%; p = 0.75). Three leading causative foods of parent-reported FA were cow's milk, shrimp, and eggs. Shrimp was still the most common OFC-confirmed food allergen. Atopic dermatitis was the most significantly parent reported factor associated with FA.

Conclusion

The overall prevalence of FA among preschool children in Northern Thailand had not increased during the past decade. There was no significant difference in the prevalence of OFC-confirmed FA between 2010 and 2019.

Natural immunomodulating substances used for alleviating food allergy

Food allergy is a serious health problem affecting more than 10% of the human population worldwide. Medical treatments for food allergy remain limited because immune therapy is risky and costly, and anti-allergic drugs have many harmful side effects and can cause drug dependence. In this paper, we review natural bioactive substances capable of alleviating food allergy. The sources of the anti-allergic substances reviewed include plants, animals, and microbes, and the types of substances include polysaccharides, oligosaccharides, polyphenols, phycocyanin, polyunsaturated fatty acids, flavonoids, terpenoids, quinones, alkaloids, phenylpropanoids, and probiotics. We describe five mechanisms involved in anti-allergic activities, including binding with epitopes located in allergens, affecting the gut microbiota, influencing intestinal epithelial cells, altering antigen presentation and T cell differentiation, and inhibiting the degranulation of effector cells. In the discussion, we present the limitations of existing researches as well as promising advances in the development of anti-allergic foods and/or immunomodulating food ingredients that can effectively prevent or alleviate food allergy. This review provides a reference for further research on anti-allergic materials and their hyposensitizing mechanisms.

Processes for reducing egg allergenicity: Advances and different approaches

Egg is a versatile ingredient and ubiquitous food. Nevertheless, egg proteins are a common cause of allergy mainly in childhood. Until now, egg eviction has been the best way to prevent this disorder, however, processed food can contribute to mitigate allergies and to guarantee life quality of allergic individuals. This review focuses on discussing and highlighting recent advances in processes to reduce egg allergenicity as well as new approaches to egg allergy management. In recent times, different methods have been developed to reduce egg allergies, by hiding the epitopes or changing the native or conformational structure of the proteins. Despite processing food has not yet been a solution to completely remove the allergenic potential of egg proteins, innovative strategies, such as addition of phenolic compounds, have been developed with promising results.