The US population-level burden of cow's milk allergy

Food-triggered anaphylaxis in adults

PURPOSE OF REVIEW

Adult food allergy, either unresolved from childhood, or new-onset in adult-life, is known to be increasingly prevalent. Although much of the reported anaphylaxis in adults is due to drug reactions, foods are becoming an increasingly important trigger, affecting adults of all ages, with a wide variation in food triggers which are often quite different to those reported in children.

RECENT FINDINGS

Peanuts are well known to cause anaphylaxis in some adult populations, but other legumes such as soy may be more relevant in others. Reactions to natto, fermented soybeans, are currently mainly reported in Japan, but changing dietary practices and an increase in plant-based eating mean natto, other forms of soy and other legumes are increasingly linked to anaphylaxis in Western countries. Anaphylaxis to red meat, caused by sensitization to galactose-α-1,3-galactose and first reported in North America, is now a more world-wide concern. Co-factor induced anaphylaxis is increasingly associated with both wheat allergy and lipid transfer protein allergy.

SUMMARY

More research is urgently needed to characterize adult food allergy, its triggers and symptom severity. Unusual food triggers and potential co-factors should be considered, so that anaphylaxis in adults can be correctly managed, not merely labelled as idiopathic.

Varying Doses of Epicutaneous Immunotherapy With Viaskin Milk vs Placebo in Children With Cow's Milk Allergy: A Randomized Clinical Trial

Importance

No approved treatment exists for allergen-specific immunoglobulin E (IgE)-mediated cow's milk allergy (CMA), a common childhood food allergy.

Objective

To assess dose, efficacy, and safety of epicutaneous immunotherapy with Viaskin milk in children with IgE-mediated CMA.

Design, Setting, and Participants

A phase 1/2, 2-part, randomized, double-blind, placebo-controlled dose-ranging clinical trial in children aged 2 to 17 years with IgE-mediated CMA was conducted between November 2014 through December 2017. It took place at 17 trial sites in the US and Canada. Current CMA was confirmed by double-blind, placebo-controlled food challenge at study entry. Part A assessed the short-term safety of 150 μg, 300 μg, or 500 μg of Viaskin milk; part B evaluated the efficacy and safety of the 3 doses vs placebo over 12 months of treatment. Of the 308 screened participants with physician-diagnosed CMA, 198 met eligibility criteria (including an eliciting dose 300 mg or less) and were randomized.

Intervention

Safety of Viaskin milk (150-μg, 300-μg, or 500-μg doses) was evaluated over a 3-week period (part A). In part B, 180 additional participants were randomized to receive Viaskin milk at doses of 150 μg, 300 μg, or 500 μg or placebo (1:1:1:1) for 12 months.

Main Outcomes and Measures

The primary outcome was the proportion of treatment responders, defined as a 10-fold or more increase in the cumulative reactive dose of cow's milk protein (reaching at least 144 mg) or a cumulative reactive dose of cow's milk protein at 1444 mg or more at the month 12 double-blind, placebo-controlled food challenge.

Results

A total of 95.5% of the randomized participants (mean [SD] age, 8 [4.17] years; 124 of 198 were male [62.6%]) completed treatment. The highest response rate was observed in participants who received Viaskin milk at the 300-μg dose with 24 of 49 responders (49.0%) overall vs 16 of 53 responders (30.2%) in the placebo group (odds ratio, 2.19; 95% CI, 0.91-5.41; P = .09), highest in the 2 to 11 years age group (22 of 38 [57.9%] vs 13 of 40 [32.5%]; P = .04). Most treatment-emergent adverse events were mild or moderate application-site reactions. One participant in the 500-μg Viaskin milk dose group experienced treatment-related anaphylaxis.

Conclusions and Relevance

In this randomized clinical trial, 12 months of daily epicutaneous immunotherapy with a dose of Viaskin milk at 300 μg was associated with a statistically significant treatment response in 2- to 11-year-old children with IgE-mediated CMA. Treatment-related anaphylaxis and treatment-related discontinuation rates were low. Further research is needed to explore Viaskin milk as a viable treatment option for children with IgE-mediated CMA.

Trial Registration

ClinicalTrials.gov Identifier: NCT02223182.

Baked milk and egg diets revisited

Most children with milk and egg allergy are nonreactive to modified forms of milk and egg in bakery products such as muffins because of conformational changes in proteins. These baked milk (BM) and baked egg (BE) diets have become commonplace in the management of milk and egg allergy, respectively. Current laboratory- and skin test-based diagnostic approaches remain limited in their ability to predict BM/BE tolerance, resulting in various approaches to introduce these foods. One approach to introduce BM/BE is to offer a medically supervised oral food challenge and then advise dietary introduction of baked products for children who have tolerance. Another approach is adapted from a home-based protocol of graded ingestion of BM or BE originally intended for non-IgE mediated allergy, often referred to as a "ladder." The ladder advises home ingestion of increasing amounts of BM or BE. For children who have allergy to BM or BE, the ladder is essentially oral immunotherapy, although not always labeled or recognized as such. Risk assessment and education of patients suitable for home introduction are essential. A home approach that may be called a ladder can also be used to escalate diets after demonstrated tolerance of baked forms by introducing lesser cooked forms of milk or egg after tolerating BM or BE. A randomized controlled trial provided clear evidence that baked diets can hasten the resolution of IgE-mediated milk allergy. Moreover, BM/BE foods have an emerging role in the treatment of non-IgE-mediated allergy. There is tangential evidence for BM and BE diets in the prevention of IgE-mediated allergy.

Evaluation of ELISA Test Kits for Detection of Milk Protein in Frying Oil Treated at Different Temperatures

Milk is a common ingredient in fried foods. Allergen cross-contact can occur through the reuse of frying oil. To enable assessment of the allergy risk of reused oil, methods for quantification of milk protein in oil are needed. This study evaluated four commercial ELISA test kits in comparison with the 660 nm total protein assay for the detection of milk protein in oil after frying. Corn oil spiked with nonfat or whole milk powder were fried at 150 °C or 180 °C for 3 min and were analyzed by ELISA kits either directly or after preextraction with phosphate-buffered saline containing 0.05% Tween (PBST). All four ELISA kits performed well in quantifying milk protein in unheated oil, achieving normalized recoveries of 72.1-115.9% compared with that determined in reference solutions (PBST spiked with nonfat or whole milk powder, 100%). Frying lowered the amount of protein detected, but the extent of reduction differed between test kits. In nonfat milk powder-spiked oil fried at 150 °C, normalized recoveries determined by Veratox Total Milk and BioKits BLG Assay (49.9% and 43.6%, respectively) were higher than that determined by the 660 nm assay (25.4%). Normalized recoveries determined by ELISA Systems Casein and Beta-Lactoglobulin (BLG) kits were substantially lower (9.7% and 2.4%, respectively). In samples fried under typical frying temperature (180 °C), very little protein (0.1-7.4%) was detected. Inclusion of PBST preextraction improved the detection of the two test kits targeting BLG but lowered the level of protein detected by Veratox and ELISA Systems Casein in fried samples. Overall, the ELISA kits evaluated could effectively quantify milk protein in unheated oil without the need to remove the oil phase prior to analysis. Heat treatment was the key factor negatively affecting protein quantitation. Such impact needs to be considered when ELISA test results are used for assessing the allergy risk of reused frying oil.

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.

Adult-onset IgE-mediated cow's milk allergy-a rare phenotype

Cow's milk allergy has been studied extensively in infants and young children and has public health importance around the globe. We describe the clinical and demographic characteristics of 3 cases of a rare presentation of adult-onset IgE-mediated cows' milk allergy.

Allergen Stability in Food Allergy: A Clinician's Perspective

PURPOSE OF REVIEW

The globally rising food allergy prevalence is associated with the urgent need for new disease prevention methods, efficient treatment, and reliable risk assessment methods for characterization of food allergens. Due to inter-individual variations in the digestive system, food allergens are degraded to a different extent in each person. Food processing also influences allergen digestion.

RECENT FINDINGS

In this review, we provide an overview of the digestive system with focus on relevance for food allergy. Main food proteins causing allergic reactions are evaluated, and the combined role of food processing and digestion for allergen stability is highlighted. Finally, clinical implications of this knowledge are discussed. Recent literature shows that allergen digestibility is dependent on food processing, digestive conditions, and food matrix. Digestion affects proteins allergenicity. It is currently not possible to predict the immunogenicity of allergens solely based on protein stability.

Pilot Study of the Applicability, Usability, and Accuracy of the Nutricate© Online Application, a New Dietary Intake Assessment Tool for Managing Infant Cow's Milk Allergy

BACKGROUND/OBJECTIVES

The mainstay treatment of cow's milk allergy (CMA) is to remove cow's milk proteins from children's dietary intake. In this context, dietary intake of children with CMA should be particularly checked and monitored. The objective of this study was to assess the applicability, usability, and accuracy of a new dietary intake (DI) assessment online tool (Nutricate© online application) for managing CMA in children.

SUBJECTS/METHODS

This study used a pre-existing database of DI from the Nutricate© online application. DIs from 30 CMA children were used to compare micro/macronutrients (energy, protein, calcium, and iron intakes) calculated by Nutricate© and NutriLog© as the reference method. Comparisons were performed using the Pearson correlation analysis and the Bland-Altman plot. The Nutricate© tool usability was assessed via a System Usability Scale questionnaire (SUSq).

RESULTS

Correlation coefficient between the levels of micro/macronutrients obtained by Nutrilog© and Nutricate© software were highly significant (p = 0.0001) and were well-correlated (R coefficient > 0.6), indicating a very good concordance between the two methods. This observation was reinforced by the Bland-Altman plot, indicating the absence of proportional or fixed bias for energy, protein, calcium, and iron intakes. The mean SUSq score obtained was 81 ± 14, which is considered to be an excellent score.

CONCLUSIONS

Nutricate© online application is a reliable method to assess micro/macronutrient (energy, protein, calcium, and iron intakes) intake in CMA children. Applicability and usability of this new dietary intake assessment online tool is excellent.

Social disparities in early childhood prevention and management of food allergy

Food allergy (FA) affects 8% of US children. Navigating and managing FA permeates across multiple facets of childhood. In this article, we review research on social disparities in feeding practices, managing meals, and selecting childcare and schools. Key highlights include the following: (1) although preference for breast-feeding or formula feeding does not reduce FA risk, there are disparities in access to formula that may affect children with FA; (2) disparities likely exist in the early introduction to allergenic foods, though additional research is needed to identify barriers to following the most recent consensus guidelines on early introduction; (3) families with limited income face challenges in providing safe meals for their children; (4) disparities exist in early childcare options for preschool-age children, though there is a lack of research on FA practices in these settings; and (5) there is evidence that schools with different student demographics implement different types of FA policies. Further research is needed to better understand and characterize social disparities in FA prevention and management in early childhood and to develop evidence-based strategies to reduce them.

Oral Immunotherapy for Children with Cow's Milk Allergy: A Practical Approach

Cow milk allergy (CMA) is a prevalent disease in childhood. Natural history is usually favorable as CMA can disappear by school age in many subjects. Diagnosis corresponds to treatment, as an elimination diet is a solution. However, cow's milk (CM) is real food, hardly replaceable. Thus, CM reintroduction represents a demanding challenge in clinical practice. The induction of CM tolerance could be achievable using oral immunotherapy (OIT), such as the administration of increasing milk quantities until reaching tolerance. However, the OIT schedule and procedure need to be better standardized, and performance may vary widely. Therefore, the present study reports the practical experience of a third-level pediatric allergy center in managing children with CMA and submitting them to OIT. OFC and OIT are relatively safe procedures as the reaction rate is low. Almost two-thirds of the OIT subjects tolerated CM. Reactions were associated with high IgE levels. Therefore, the present experience, developed by a qualified center, may suggest and propose a practical approach for managing children with CMA. After the initial workup, including a thorough history, physical examination, and laboratory tests, OFC and, when indicated, OIT could be performed in most children with CMA.

Alteration of the allergenicity of cow's milk proteins using different food processing modifications

Milk is an essential source of protein for infants and young children. At the same time, cow's milk is also one of the most common allergenic foods causing food allergies in children. Recently, cow's milk allergy (CMA) has become a common public health issue worldwide. Modern food processing technologies have been developed to reduce the allergenicity of milk proteins and improve the quality of life of patients with CMA. In this review, we summarize the main allergens in cow's milk, and introduce the recent findings on CMA responses. Moreover, the reduced effects and underlying mechanisms of different food processing techniques (such as heating, high pressure, γ-ray irradiation, ultrasound irradiation, hydrolysis, glycosylation, etc.) on the allergenicity of cow's milk proteins, and the application of processed cow's milk in clinical studies, are discussed. In addition, we describe the changes of nutritional value in cow's milk treated by different food processing technologies. This review provides an in-depth understanding of the allergenicity reduction of cow's milk proteins by various food processing techniques.