Natural course of IgE-mediated food allergy in children

Scientific developments in understanding food allergy prevention, diagnosis, and treatment

Food allergies (FAs) are adverse immune reactions to normally innocuous foods. Their prevalence has been increasing in recent decades. They can be IgE-mediated, non-IgE mediated, or mixed. Of these, the mechanisms underlying IgE-mediated FA are the best understood and this has assisted in the development of therapeutics. Currently there are two approved drugs for the treatment of FA, Palforzia and Omalizumab. Palfornia is a characterized peanut product used as immunotherapy for peanut allergy. Immunotherapy, involves exposure of the patient to small but increasing doses of the allergen and slowly builds immune tolerance to the allergen and increases a patient's allergic threshold. Omalizumab, a biologic, is an anti-IgE antibody which binds to IgE and prevents release of proinflammatory allergenic mediators on exposure to allergen. Other biologics, investigational vaccines, nanoparticles, Janus Kinase and Bruton's tyrosine kinase inhibitors, or DARPins are also being evaluated as potential therapeutics. Oral food challenges (OFC) are the gold standard for the diagnosis for FA. However, they are time-consuming and involve risk of anaphylaxis; therefore, alternative diagnostic methods are being evaluated. This review will discuss how the immune system mediates an allergic response to specific foods, as well as FA risk factors, diagnosis, prevention, and treatments for FA.

The utility of casein skin prick test and IgE values in predicting anaphylaxis and reactivity to baked milk

BACKGROUND

Most children with milk allergy can tolerate baked milk (BM); however, a small percent still react to it. Identifying indicators that might forecast potential reactions to baked goods is essential.

OBJECTIVE

To determine the predictive factors and some decision points for estimation of BM reactivity and severe reactions.

METHODS

A cross-sectional study was performed. Participants who were reactive to unheated milk underwent an oral food challenge with BM. The reactive group was classified into anaphylactic and non-anaphylactic reaction categories. The IgE and skin prick test (SPT) levels of milk and its components were compared among these groups.

RESULTS

The study was conducted with 110 patients. The median age of participants was 16 (IQR: 12-31) months. BM reactivity was observed in 41% (n = 46/110) of the patients. The optimal cutoff point for BM reactivity was 4.68 kIU/L for casein specific IgE (sIgE) (84% specificity, 75% sensitivity, area under the curve [AUC]: 0.827) and 7 mm for casein SPT (87.2% specificity, 51.1% sensitivity, AUC: 0.721) (P < .001, P < .001). The positive decision point for anaphylaxis for casein sIgE was 34 kIU/L (95% specificity, 47.6% sensitivity, AUC: 0.707). In the group younger than 24 months old, the cutoff values for casein sIgE were found to be 5.4 kIU/L (95% specificity, 66.6% sensitivity, AUC: 0.844) and casein SPT at 7 mm (91% specificity, 37% sensitivity, AUC: 0.708) (P < .001, P = .002).

CONCLUSION

Our investigation revealed that the most accurate indicator for BM reactivity was casein sIgE and SPT. Although we established a threshold for severe reaction with BM in our study population, we consider that our findings require validation before therapeutic implementation.

"When I became older, I started having to manage that more myself"-Experiences of adolescents with food allergies: A qualitative study

BACKGROUND

It's often caregivers or healthcare professionals' experiences that are studied in the field of allergy, but the adolescents' perspective is crucial to develop interventions that support them in areas they find most challenging. This study aims to explore adolescents' experience of managing food allergies, particularly how they navigate the transition from parental management to self-management.

METHODS

This is an interpretive descriptive qualitative study. Semi-structured interviews were conducted with ten adolescents with food allergies aged 12-16 years. Reflexive thematic analysis was conducted. The Reflexive Thematic Analysis Reporting Guidelines were used.

RESULTS

Four themes were generated, (1) belonging-seeing me, (2) not knowing (3) taking responsibility-"So I guess when I became older, I started having to manage that more myself" and (4) variation in coping strategies. These describe adolescents need for belonging, that their peers acknowledge their food allergies without making them feel like a burden. Adolescents understanding of essential food allergy information was lacking, with some unaware of this lack of knowledge. Adolescents were conscious of the need to take over responsibility from their parents, although this could be difficult. Finally, how adolescents coped with all these aspects of their food allergy could be seen as avoidant due to high anxiety, minimizing of risk, or adaptive, where adolescents are aware of and mitigate risks appropriately, without avoiding life experiences.

CONCLUSION

Adolescents find the transition of responsibility from their parents difficult. A trusted source of allergy information is required, aimed at adolescents, covering both physical allergy management and psychosocial content.

Buckwheat Allergy in Asia

PURPOSE OF REVIEW

Buckwheat (BW) allergy is a significant issue in Asia. This review delves into three types of BW allergy: immediate food allergy; food-dependent, exercise-induced anaphylaxis (FDEIA) as a subset of immediate food allergy; and food protein-induced enterocolitis syndrome (FPIES); by comparing data from Asian and non-Asian countries.

RECENT FINDINGS

Most studies on BW have been published in Japan and Korea, and only a few studies on the topic have been done outside Asia. To date, seven components of common BW (Fagopyrum esculentum) and four components of Tartary BW (Fagopyrum tartaricum) have been implicated in BW allergy. Although BW-sIgE has limited utility for evaluating immediate BW allergy, Fag e 3-specific IgE, one of the components of common BW, and the skin prick test are diagnostically useful. The present review aims to shed light on the current state of knowledge, highlight research gaps, and suggest future directions in the management and understanding of BW allergy.

Risk Factors for Severe Seafood Allergy Among Adults in an Urban City in Vietnam

Purpose

Increasing seafood consumption is associated with more frequent reports of food allergy. Little is known about seafood allergy (SFA) among adults in Vietnam. We investigated the characteristics of individuals with SFA and the risk factors for severe SFA.

Patients and methods

A cross-sectional, web-based survey was conducted among individuals aged ≥ 18 years from universities in Ho Chi Minh City (Vietnam) between December 2021 and July 2022. The survey was based on a structured, validated questionnaire related to FA. Strict definitions of "convincing allergy" were used. Multivariate analysis was used to estimate the risk factors for severe SFA after adjusting for covariates. Data were analyzed using JASP (v.0.16.3) and SPSS (v.22.0).

Results

Totally, 1038 out of 2137 (48.57%) individuals completed the questionnaire, of whom 285 (27.46%) had reported SFA. Convincing SFA accounted for 20.13% (209/1038) of the cases, with convincing shellfish allergy being more common than fish allergy. Participants with comorbid shellfish and fish allergy had higher prevalence of atopic dermatitis, peanut/nut allergy, other food allergy, and cutaneous and upper airway symptoms compared to participants with shellfish allergy (p < 0.05). The spectrum of reactive seafood was diverse and characterized by local species. The age of symptom onset was most commonly during late childhood and adolescence, with most reactions persisting into adulthood. A history of anaphylaxis, comorbid peanut, and tree nut allergy, and ≥3 allergens were associated with severe SFA.

Conclusion

Features of causative, coexisting seafood allergy, and risk factors for severe SFA were demonstrated, which can provide a reference for future studies.

The Role of Regulatory T Cells in Allergic Diseases: Collegium Internationale Allergologicum (CIA) Update 2024

BACKGROUND

Allergy represents a major health problem of increasing prevalence worldwide with a high socioeconomic impact. Our knowledge on the molecular mechanisms underlying allergic diseases and their treatments has significantly improved over the last years. The generation of allergen-specific regulatory T cells (Tregs) is crucial in the induction of healthy immune responses to allergens, preventing the development and worsening of allergic diseases.

SUMMARY

In the last decades, intensive research has focused on the study of the molecular mechanisms involved in Treg development and Treg-mediated suppression. These mechanisms are essential for the induction of sustained tolerance by allergen-specific immunotherapy (AIT) after treatment discontinuation. Compelling experimental evidence demonstrated altered suppressive capacity of Tregs in patients suffering from allergic rhinitis, allergic asthma, food allergy, or atopic dermatitis, as well as the restoration of their numbers and functionality after successful AIT.

KEY MESSAGE

The better understanding of the molecular mechanisms involved in Treg generation during allergen tolerance induction might well contribute to the development of novel strategies for the prevention and treatment of allergic diseases.

Variation in the Allergenicity of Scrambled, Boiled, Short-Baked and Long-Baked Egg White Proteins

BACKGROUND

Hen's egg white (HEW) is the most common cause of food allergy in children which induces mild to fatal reactions. The consultation for a proper restriction is important in HEW allergy. We aimed to identify the changes in HEW allergenicity using diverse cooking methods commonly used in Korean dishes.

METHODS

Crude extract of raw and 4 types of cooked HEW extracts were produced and used for sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), enzyme-linked immunosorbent assay (ELISA), and ELISA inhibition assays using 45 serum samples from HEW allergic and tolerant children. Extracts were prepared; scrambled without oil for 20-30 seconds in frying pan without oil, boiled at 100°C for 15 minutes, short-baked at 180°C for 20 minutes, and long-baked at 45°C for 12 hours with a gradual increase in temperature up to 110°C for additional 12 hours, respectively.

RESULTS

In SDS-PAGE, the intensity of bands of 50-54 kDa decreased by boiling and baking. All bands almost disappeared in long-baked eggs. The intensity of the ovalbumin (OVA) immunoglobulin E (IgE) bands did not change after scrambling; however, an evident decrease was observed in boiled egg white (EW). In contrast, ovomucoid (OM) IgE bands were darker and wider after scrambling and boiling. The IgE binding reactivity to all EW allergens were weakened in short-baked EW and considerably diminished in long-baked EW. In individual ELISA analysis using OVA+OM+ serum samples, the median of specific IgE optical density values was 0.435 in raw EW, 0.476 in scrambled EW, and 0.487 in boiled EW. Conversely, it was significantly decreased in short-baked (0.406) and long-baked EW (0.012). Significant inhibition was observed by four inhibitors such as raw, scrambled, boiled and short-baked HEW, but there was no significant inhibition by long-baked HEW (IC50 > 100 mg/mL).

CONCLUSION

We identified minimally reduced allergenicity in scrambled EW and extensively decreased allergenicity in long-baked EW comparing to boiled and short-baked EW as well as raw EW. By applying the results of this study, we would be able to provide safer dietary guidence with higher quality to egg allergic children.

Probiotics in Infancy and Childhood for Food Allergy Prevention and Treatment

Food allergy represents a failure of oral tolerance mechanisms to dietary antigens. Over the past few years, food allergies have become a growing public health problem worldwide. Gut microbiota is believed to have a significant impact on oral tolerance to food antigens and in initiation and maintenance of food allergies. Therefore, probiotics have also been proposed in this field as a possible strategy for modulating both the gut microbiota and the immune system. In recent years, results from preclinical and clinical studies suggest a promising role for probiotics in food allergy prevention and treatment. However, future studies are needed to better understand the mechanisms of action of probiotics in food allergies and to design comparable study protocols using specific probiotic strains, defined doses and exposure times, and longer follow-up periods.