Tolerance to extensively heated milk in children with cow's milk allergy

Impact of processing on the sensitising capacity and cross-reactivity of cow's and camel milk proteins in a Brown Norway rat study

Infant formulas based on hydrolysed cow's milk proteins are used when breastfeeding is not feasible in cow's milk allergic infants. Camel milk has been shown to be well-tolerated by the majority of children with cow's milk allergy (CMA) and may be a substitute in management of CMA. Here we aimed to evaluate the impact of processing on immunogenicity, sensitising, antibody-binding and cross-reactive capacity of cow's and camel milk. Cow's and camel milk were processed by means of enzyme hydrolysis or heat treatment. Brown Norway rats were immunised with PBS, non-processed, enzyme hydrolysed or heat-treated cow's or camel milk. In vivo tests were performed for evaluation of clinical signs. Blood and faecal samples were analysed for levels and specificity of antibody responses. Cow's and camel milk showed similar sensitising capacity. Processing decreased the sensitising capacity of cow's milk, yet only enzyme hydrolysis but not heat treatment decreased the sensitising capacity of camel milk. Processing affected the specificity of antibodies raised in the rats, though the effect differed between cow's and camel milk. The study showed a low cross-reactivity between cow's and camel milk, which was decreased with processing, suggesting that processing of camel milk may improve its usefulness in CMA management.

Development of a low allergenic product for patients with milk allergy and assessment of its specific IgE reactivity

BACKGROUND

Milk oral immunotherapy is the riskiest and most unpredictable form of oral immunotherapy. We aimed to produce a low allergenic product than conventional once baked-cake/muffin, to develop indirect in-house ELISA to check the tolerance status with milk products and evaluate IgE reactivity of patients' sera via western blotting (WB) and indirect in-house ELISA.

METHOD

A low allergenic product named biscotti-twice baked-cake was developed, and the total protein concentration was determined. The protein content was studied by SDS-PAGE and proteomics. Milk-specific IgE (sIgE) binding assays were performed by WB and indirect in-house ELISA by using patients' sera.

RESULTS

Casein band intensity was observed to be lower in the biscotti-twice baked-cake than in the once baked-cake (p = .014). Proteomics analysis and αS1-casein measurement showed that the lowest intensity of casein was found in biscotti. The low binding capacity of milk sIgE to biscotti compared with once baked-cake was shown by WB (p = .0012) and by indirect in-house ELISA (p = .0001). In the ROC analysis, the area under the curve (AUC) of the in-house ELISA IgE was comparable with Uni-CAP milk and casein sIgE. The AUC of the in-house ELISA IgE for cake (0.96) and biscotti (1) was slightly better than Uni-CAP milk sIgE (0.94; 0.97) and casein sIgE (0.96; 0.97), respectively.

CONCLUSION

The low allergenicity of the newly developed low allergenic product "biscotti-twice baked-cake" has been demonstrated by in vitro experiments. Biscotti could be a safe treatment option than once baked-cake/muffin in patients who are reactive to once baked-milk products.

Nutritional and Psychosocial Impact of Food Allergy in Pediatric Age

Treatment of IgE-mediated food allergy involves avoiding the food causing the allergic reaction. In association, an action plan for allergic reactions is indicated, sometimes including self-injectable adrenaline. In addition to these dietary and medical implications, there are two equally important ones: nutritional and psychosocial. From a nutritional point of view, it is known that children suffering from food allergy have a growth delay in height and weight compared to their non-allergic peers. Specifically, this condition is directly related to the specific food excluded from the diet, the number of foods excluded and the duration of the elimination diet. From a psychosocial point of view, the child often cannot eat the foods other guests eat. Children with food allergy may perceive an aura of parental anxiety around their mealtime and may be afraid that what they eat could have harmful consequences for their health. Furthermore, children's and their parents' quality of life appears to be affected. The need to manage the allergy and the nutritional and psychosocial problems positions the pediatric nutritionist and the child neuropsychiatrist as support figures for the pediatric allergist in managing the child with food allergy.

Precision engineering for localization, validation, and modification of allergenic epitopes

The allergen-IgE interaction is essential for the genesis of allergic responses, yet investigation of the molecular basis of these interactions is in its infancy. Precision engineering has unveiled the molecular features of allergen-antibody interactions at the atomic level. High-resolution technologies, including x-ray crystallography, nuclear magnetic resonance spectroscopy, and cryo-electron microscopy, determine allergen-antibody structures. X-ray crystallography of an allergen-antibody complex localizes in detail amino acid residues and interactions that define the epitope-paratope interface. Multiple structures involving murine IgG mAbs have recently been resolved. The number of amino acids forming the epitope broadly correlates with the epitope area. The production of human IgE mAbs from B cells of allergic subjects is an exciting recent development that has for the first time enabled an actual IgE epitope to be defined. The biologic activity of defined IgE epitopes can be validated in vivo in animal models or by measuring mediator release from engineered basophilic cell lines. Finally, gene-editing approaches using the Clustered Regularly Interspaced Short Palindromic Repeats technology to either remove allergen genes or make targeted epitope engineering at the source are on the horizon. This review presents an overview of the identification and validation of allergenic epitopes by precision engineering.

Dietary management of IgE and non-IgE-mediated food allergies in pediatric patients

Food allergies (FA) consist of both IgE and non-IgE-mediated entities, with varying phenotypes and overlapping and different considerations for each specific disease presentation. In general, all FAs place children at increased risk for inadequate nutritional intake and negative impacts on their nutritional status, as well as negative impacts on the quality of life for the entire family. To minimize these untoward effects, a multidisciplinary approach should be taken, including consultation and management with a dietitian trained in the varying presentations of FA. Families should be instructed on label reading as a first line of nutritional management. During a nutrition consultation, the age of the child, growth, and nutritional status should be considered. Food refusal should be assessed and addressed. Families should be educated on avoidance and appropriate substitutions. In the case of cow's milk allergy, a suitable specialized formula should be suggested if the infant is not breastfed or if breast milk supply is not sufficient. Other mammalian milk should be avoided and careful consideration should be given before plant-based milk is used in young children. Specific food allergies may differ in terms of advice provided on the level of avoidance required, whether precautionary advisory labels should be avoided, and if a maternal avoidance of the allergen during breastfeeding should be advised. The role of immunonutrition on overall health should be discussed.

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.

The future of cow's milk allergy - milk ladders in IgE-mediated food allergy

Cow's milk allergy (CMA) is one of the most common and complex presentations of allergy in early childhood. CMA can present as IgE and non-IgE mediated forms of food allergy. Non-IgE mediated CMA includes food protein-induced enterocolitis syndrome (FPIES), eosinophilic gastrointestinal disorders (EGIDs), and food protein-induced proctocolitis (FPIAP). There are recent guidelines addressing CMA diagnosis, management, and treatment. Each of these guidelines have their own strengths and limitations. To best manage CMA, individualized avoidance advice should be given. Cow's milk (CM) can be replaced in the diet by using hypoallergenic formulas or plant-based milk, depending on factors such as the child's age and their current food intake. Oral and epicutaneous immunotherapy is used to increase tolerance in children with CMA but is not without risk, and the long-term outcome of sustained unresponsiveness is still unclear. The allergenicity of CM proteins are affected differently by different forms of heating, leading to the use of baked milk or milk ladders in the management of CMA, most likely the most promising option for future management and treatment of CMA. Future management of children with CMA will also include discussion around the immunomodulatory potential of the child's dietary intake.

An ESPGHAN Position Paper on the Diagnosis, Management, and Prevention of Cow's Milk Allergy

A previous guideline on cow's milk allergy (CMA) developed by the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) was published in 2012. This position paper provides an update on the diagnosis, treatment, and prevention of CMA with focus on gastrointestinal manifestations. All systematic reviews and meta-analyses regarding prevalence, pathophysiology, symptoms, and diagnosis of CMA published after the previous ESPGHAN document were considered. Medline was searched from inception until May 2022 for topics that were not covered in the previous document. After reaching consensus on the manuscript, statements were formulated and voted on each of them with a score between 0 and 9. A score of ≥6 was arbitrarily considered as agreement. Available evidence on the role of dietary practice in the prevention, diagnosis, and management of CMA was updated and recommendations formulated. CMA in exclusively breastfed infants exists, but is uncommon and suffers from over-diagnosis. CMA is also over-diagnosed in formula and mixed fed infants. Changes in stool characteristics, feeding aversion, or occasional spots of blood in stool are common and in general should not be considered as diagnostic of CMA, irrespective of preceding consumption of cow's milk. Over-diagnosis of CMA occurs much more frequently than under-diagnosis; both have potentially harmful consequences. Therefore, the necessity of a challenge test after a short diagnostic elimination diet of 2-4 weeks is recommended as the cornerstone of the diagnosis. This position paper contains sections on nutrition, growth, cost, and quality of life.

Standardization of food allergen ladders for optimal effectiveness and patient safety

The use of extensively heated (EH) milk and egg products, and dietary advancement therapies such as milk and egg ladders is increasingly common for the management of milk and egg allergies. Although the majority of patients with milk and egg allergies will outgrow their allergies, the ability to tolerate extensively hydrolyzed forms of these allergens is an early indicator of developing long-term tolerance. The denaturation of conformational epitopes during the heating process reduces the allergenicity of these proteins, which makes patients who are EH tolerant more likely to tolerate progressively more of these proteins.

Identification of cow milk epitopes to characterize and quantify disease-specific T cells in allergic children

BACKGROUND

Cow milk (CM) allergy is the most prevalent food allergy in young children in the United States and Great Britain. Current diagnostic tests are either unreliable (IgE test and skin prick test) or resource-intensive with risks (food challenges).

OBJECTIVE

We sought to determine whether allergen-specific T cells in CM-allergic (CMA) patients have a distinct quality and/or quantity that could potentially be used as a diagnostic marker.

METHODS

Using PBMCs from 147 food-allergic pediatric subjects, we mapped T-cell responses to a set of reactive epitopes in CM that we compiled in a peptide pool. This pool induced cytokine responses in in vitro cultured cells distinguishing subjects with CMA from subjects without CMA. We further used the pool to isolate and characterize antigen-specific CD4 memory T cells using flow cytometry and single-cell RNA/TCR sequencing assays.

RESULTS

We detected significant changes in the transcriptional program and clonality of CM antigen-specific (CM+) T cells elicited by the pool in subjects with CMA versus subjects without CMA ex vivo. CM+ T cells from subjects with CMA had increased percentages of FOXP3+ cells over FOXP3- cells. FOXP3+ cells are often equated with regulatory T cells that have suppressive activity, but CM+ FOXP3+ cells from subjects with CMA showed significant expression of interferon-responsive genes and dysregulated chemokine receptor expression compared with subjects without CMA, suggesting that these are not conventional regulatory T cells. The CM+ FOXP3+ cells were also more clonally expanded than the FOXP3- population. We were further able to use surface markers (CD25, CD127, and CCR7) in combination with our peptide pool stimulation to quantify these CM+ FOXP3+ cells by a simple flow-cytometry assay. We show increased percentages of CM+ CD127-CD25+ cells from subjects with CMA in an independent cohort, which could be used for diagnostic purposes. Looking specifically for TH2 cells normally associated with allergic diseases, we found a small population of clonally expanded CM+ cells that were significantly increased in subjects with CMA and that had high expression of TH2 cytokines and pathogenic TH2/T follicular helper markers.

CONCLUSIONS

Overall, these findings suggest that there are several differences in the phenotypes of CM+ T cells with CM allergy and that the increase in CM+ FOXP3+ cells is a potential diagnostic marker of an allergic state. Such markers have promising applications in monitoring natural disease outgrowth and/or the efficacy of immunotherapy that will need to be validated in future studies.

A review of food allergy panels and their consequences

Serum immunoglobulin E (IgE) assays to food specific IgE (s-IgE) are useful tools for the confirmation of clinical suspicion of food allergy. However, the specificity of these assays is poor given that sensitization is much more common than clinical food allergy. Therefore, the use of broad panels to assess sensitization to multiple foods often leads to overdiagnosis and unnecessary food avoidance. Unintended consequences that may occur as a result include physical harm, psychological harm, financial cost, opportunity cost, and even worsening of existing health care disparities. Although current guidelines recommend against the use of s-IgE food panel testing, these tests are widely available and frequently used. To limit the negative impacts of s-IgE food panel testing, further work is needed to effectively spread the message that these food panels may cause unintended harm to patients and families.

The Need for Culturally Appropriate Food Allergy Management Strategies: The Indian Milk Ladder

BACKGROUND

Cow's milk allergy (CMA) is one of the most common and complex food allergies affecting children worldwide and, with a few exceptions, presents in the first few months of life. Baked-milk-containing diets are well tolerated in the majority of milk-allergic children and allow dietary restrictions to be relaxed. In addition, the early introduction of tolerated forms of allergenic foods to an infant's diet in small amounts may enhance the outgrowth of their milk allergy through oral tolerance induction. The methods of milk introduction vary widely across the globe.

METHODS

We convened an expert group to develop a comprehensive milk ladder based on the calculated milk protein content of Indian foods. To validate the milk ladder, the foods chosen for the ladder were analyzed and the ladder was re-evaluated based on the cooked milk protein content.

RESULTS

Combining expert consensus and validation of milk protein content, we created the world's first milk ladder containing Indian foods. This is the first ladder that provides information on the timing and temperature of cooking, with validated milk protein content.

CONCLUSIONS

This is the first milk ladder based on the unique features of Indian food habits built by the consensus of Indian experts along with international collaboration with laboratory quantification of milk protein in each step. We believe the "The Indian Milk Ladder" will be a very helpful tool for pediatricians helping manage CMA in children as well as their parents and caregivers, not only in India, but in countries world-wide where these foods are commonly consumed.

Baked Milk and Baked Egg Survey: A Work Group Report of the AAAAI Adverse Reactions to Foods Committee

Most milk- and egg-allergic children can tolerate milk and egg in baked forms. Some allergists have extended the use of baked milk (BM) and baked egg (BE) to advocating for the stepwise introduction of small amounts of BM and BE to children who are reactive to larger amounts of BM and BE. Little is known about the practice of introducing BM and BE and existing barriers to this approach. The purpose of this study was to gather a current assessment of the implementation of BM and BE oral food challenges and diets for milk- and egg-allergic children. We conducted an electronic survey of North American Academy of Allergy, Asthma & Immunology members offering BM and BE introduction in 2021. The response rate was 10.1% of distributed surveys (72 of 711). Surveyed allergists had a similar approach to both BM and BE introduction. Demographic features of time in practice and region of practice were significantly associated with the odds of introducing BM and BE. A wide variety of tests and clinical features guided decisions. Some allergists determined BM and BE to be appropriate for home introduction and offered this for BM and BE more often than other foods. The use of BM and BE as a food for oral immunotherapy was endorsed by almost half of respondents. Less time in practice was the most significant factor associated with offering this approach. Published recipes were used and written information was widely provided to patients by most allergists. The wide practice variabilities reveal a need for more structured guidance about oral food challenges, in-office versus home procedures, and patient education.

Recent advances in selective allergies to mammalian milk proteins not associated with Cow's Milk Proteins Allergy

Cow's milk proteins allergy (CMA) is an atypical immune system response to cow's milk and dairy products. It's one of the most common food allergies in children affecting 8% of the total pediatric population pediatric population. This comprehensive review examines recent studies in CMA, especially regarding mammalian milk allergies such as goat's, sheep's, buffalo's, camel's, mare's and donkey's milk allergies in order to increase awareness of these selective allergies and to reduce allergy risks for those who have them. The consumption of other mammalian milk types is not recommended because of the significant homology between milk proteins from cow, sheep, goat and buffalo resulting in clinical cross-reactivity. However, camel's, mare's or donkey's milk may be tolerated by some allergic patients. Selective mammalian milk allergies are unusual and rare disorders characterized by severe symptoms including angio-oedema, urticaria, respiratory manifestations and anaphylaxis. Based on the reported allergic cases, cheese products including Ricotta, Romano, Pecorino and Mozzarella, are considered as the most common source of allergens especially in goat's, sheep's and buffalo's milk allergies, while the major allergens in donkey's and mare's milk seems to be whey proteins including lysozyme, α-lactalbumin and β-lactogloblin due to the low casein/whey proteins ratio in equine's milk.

World Allergy Organization (WAO) Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guideline update - VII - Milk elimination and reintroduction in the diagnostic process of cow's milk allergy

The diagnosis of cow's milk allergy (CMA) in infants and young children remains a challenge because many of the presenting symptoms are similar to those experienced in other diagnoses. Both over- and under-diagnosis occur frequently. Misdiagnosis carries allergic and nutritional risks, including acute reactions, growth faltering, micronutrient deficiencies and a diminished quality of life for infants and caregivers. An inappropriate diagnosis may also add a financial burden on families and on the healthcare system. Elimination and reintroduction of cow's milk (CM) and its derivatives is essential for diagnosing CMA as well as inducing tolerance to CM. In non-IgE mediated CMA, the diagnostic elimination diet typically requires 2-4 weeks before reintroduction, while for IgE mediated allergy the time window may be shorter (1-2 weeks). An oral food challenge (OFC) under medical supervision remains the most reliable diagnostic method for IgE mediated and more severe types of non-IgE mediated CMA such as food protein induced enterocolitis syndrome (FPIES). Conversely, for other forms of non-IgE mediated CMA, reintroduction can be performed at home. The OFC cannot be replaced by the milk ladder after a diagnostic elimination diet. The duration of the therapeutic elimination diet, once a diagnosis was confirmed, can only be established through testing changes in sensitization status, OFCs or home reintroduction, which are directed by local protocols and services' availability. Prior non-evidence-based recommendations suggest that the first therapeutic elimination diet should last for at least 6 months or up to the age of 9-12 months, whichever is reached first. After a therapeutic elimination diet, a milk-ladder approach can be used for non-IgE mediated allergies to determine tolerance. Whilst some centers use the milk ladder also for IgE mediated allergies, there are concerns about the risk of having immediate-type reactions at home. Milk ladders have been adapted to local dietary habits, and typically start with small amounts of baked milk which then step up in the ladder to less heated and fermented foods, increasing the allergenicity. This publication aims to narratively review the risks associated with under- and over-diagnosis of CMA, therefore stressing the necessity of an appropriate diagnosis and management.

Molecular Mechanism and Clinical Effects of Probiotics in the Management of Cow's Milk Protein Allergy

Cow's milk protein allergy (CMPA) is the most common food allergy (FA) in infancy, affecting approximately 2% of children under 4 years of age. According to recent studies, the increasing prevalence of FAs can be associated with changes in composition and function of gut microbiota or "dysbiosis". Gut microbiota regulation, mediated by probiotics, may modulate the systemic inflammatory and immune responses, influencing the development of allergies, with possible clinical benefits. This narrative review collects the actual evidence of probiotics' efficacy in the management of pediatric CMPA, with a specific focus on the molecular mechanisms of action. Most studies included in this review have shown a beneficial effect of probiotics in CMPA patients, especially in terms of achieving tolerance and improving symptoms.

IgE-mediated cow's milk allergy in Brazilian children: Outcomes of oral food challenge

Background

Oral food challenge (OFC) is useful for diagnosing food allergies and assessing tolerance, but severe reactions may occur during the procedure.

Objective

To characterize the frequency and severity of reactions during cow's milk (CM) OFCs.

Methods

A cross-sectional study was conducted to analyze the outcome of cow's milk oral food challenges (CMOFCs) performed to confirm IgE-mediated CM allergy or to assess food tolerance. CM was given first as baked milk (BM), followed by whole CM if there was no prior reaction to BM. An OFC was considered positive if IgE-mediated symptoms developed up to 2 h after ingestion. Symptoms were described and variables including age at OFC, prior anaphylaxis, other atopic diseases, and skin test results were compared according to the OFC outcomes.

Results

A total of 266 CMOFCs were performed, including 159 patients with a median age of 6.3 years old. One hundred thirty-six tests were positive and 62 resulted in anaphylaxis. Thirty-nine anaphylactic reactions were observed up to 30 min after the first dose. Severe anaphylaxis (cardiovascular and/or neurological involvement) was reported in 5 tests. A second dose of epinephrine was required in 3 tests, and 1 presented a biphasic response. Younger patients had a higher risk of anaphylaxis during baked milk oral food challenge (BMOFC) (p = 0.009). The frequency of anaphylaxis was higher in patients submitted to BM (p = 0.009).

Conclusions

Anaphylaxis is a known complication of CMOFCs even when there is no prior anaphylaxis or when conducted with baked products. This study reinforces the importance of conducting OFC in appropriate settings with a well-trained team.

‘Early Introduction’ of Cow’s Milk for Children with IgE-Mediated Cow’s Milk Protein Allergy: A Review of Current and Emerging Approaches for CMPA Management

IgE-mediated cow’s milk protein allergy (CMPA) is one of the most prevalent food allergies in early childhood. Though the cornerstone of management involves the strict avoidance of milk products while awaiting natural tolerance, research increasingly shows that the rates of resolution are slowing down. Therefore, there is a need to explore alternative pathways to promote tolerance to cow’s milk in pediatric populations. This review aims to combine and appraise the scientific literature regarding the three CMPA management methods: avoidance, the milk ladder, and oral immunotherapy (OIT) and their outcomes in terms of efficacy, safety, and immunological effects. Cow’s milk (CM) avoidance virtually protects against allergic reaction until natural tolerance occurs, with hypoallergenic substitutes available in the market, but accidental ingestion represents the main issue for this strategy. Introduction to baked milk using the milk ladder was designed, with most CMPA patients successfully completing the ladder. Similar to baked milk treatment, many OIT protocols also demonstrated decreased IgE and increased IgG4 levels post protocol, as well as a reduction in wheal size diameter. Though these strategies are shown to be safe and effective in CMPA, future clinical trials should compare the safety and effectiveness of these three management strategies.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Tolerance Induction in Cow's Milk Allergic Children by Heated Cow's Milk Protein: The iAGE Follow-Up Study

Accelerating the induction of tolerance to cow's milk (CM) reduces the burden of cow's milk allergy (CMA). In this randomised controlled intervention study, we aimed to investigate the tolerance induction of a novel heated cow milk protein, the iAGE product, in 18 children with CMA (diagnosed by a paedriatric allergist). Children who tolerated the iAGE product were included. The treatment group (TG: n = 11; mean age 12.8 months, SD = 4.7) consumed the iAGE product daily with their own diet, and the control group (CG: n = 7; mean age 17.6 months, SD = 3.2) used an eHF without any milk consumption. In each group, 2 children had multiple food allergies. The follow-up procedures consisted of a double-blind placebo-controlled food challenge (DBPCFC) with CM t = 0, t = 1 (8 months), t = 2 (16 months), and t = 3 (24 months). At t = 1, eight (73%) of 11 children in the TG had a negative DBPCFC, versus four out of seven (57%) in the CG (BayesFactor = 0.61). At t = 3, nine of the 11 (82%) children in the TG and five of seven (71%) in the CG were tolerant (BayesFactor = 0.51). SIgE for CM reduced from a mean of 3.41 kU/L (SD = 5.63) in the TG to 1.24 kU/L (SD = 2.08) at the end of intervention, respectively a mean of 2.58 (SD = 3.32) in the CG to 0.63 kU/L (SD = 1.06). Product-related AEs were not reported. CM was successfully introduced in all children with negative DBPCFC. We found a standardised, well-defined heated CM protein powder that is safe for daily OIT treatment in a selected group of children with CMA. However, the benefits of inducing tolerance were not observed.

Allergic March in Children: The Significance of Precision Allergy Molecular Diagnosis (PAMD@) in Predicting Atopy Development and Planning Allergen-Specific Immunotherapy

The allergic march is a progression of naturally occurring symptoms whose nature changes with age. The classic allergic march typically begins in infancy and manifests in the form of atopic dermatitis and food allergy. As immune tolerance develops over time, these conditions may resolve by the age of 3-5 years; however, they may evolve into allergic rhinitis and bronchial asthma. Traditional diagnostic assessments, such as skin prick testing or serum allergen-specific immunoglobulin E (sIgE) level testing, are conducted to introduce effective treatment. Recent years saw the emergence of precision allergy molecular diagnosis (PAMD@), which assesses sIgE against allergenic molecules. This new technology helps more accurately evaluate the patient's allergy profile, which helps create more precise dietary specifications and personalize allergen-specific immunotherapy. This review presents possible predictions regarding the allergic march and the means of controlling it based on PAMD@ results.

Retail Food Equivalents for Post-Oral Immunotherapy Dosing in the Omalizumab as Monotherapy and as Adjunct Therapy to Multi-Allergen Oral Immunotherapy in Food-Allergic Children and Adults (OUtMATCH) Clinical Trial

BACKGROUND

Patients with food allergy may be advised to introduce specific foods into their diets, both to increase tolerance gradually and as next steps after completing oral immunotherapy or other therapeutic interventions. However, the safe use of retail foods depends on the ability to establish the specific allergen protein content of these foods.

OBJECTIVE

To develop a systematic approach to estimate the protein content of peanut, milk, egg, wheat, cashew, hazelnut, and walnut in a variety of retail food equivalents for each allergen and associated patient education materials.

METHOD

We created an algorithm that used a multistep process with information from product food labels, nutrient databases, independent weighing and measuring of foods, and information provided by manufacturers, including certificates of analysis, and e-mail communication to estimate the allergen protein content of multiple retail foods for each of seven allergens. Once a variety of retail food equivalents for each allergen and allergen serving size was determined, we developed participant education handouts, which were reviewed by study teams at 10 food allergy centers, the National Institute of Allergy and Infectious Diseases, and the Consortium for Food Allergy Research coordinating center. After 1 year of use, multiple queries were addressed and the retail food equivalents and educational materials were reviewed and edited.

RESULTS

We identified a variety of retail food equivalents for seven allergens at six serving sizes, and created 48 unique patient education materials.

CONCLUSION

Our results provide extensive guidance on a variety of retail equivalents for seven foods, and a method to estimate retail food protein equivalents systematically with ongoing reassessment.

Precautionary Allergen Labeling: What Advice Is Available for Health Care Professionals, Allergists, and Allergic Consumers?

In most countries, the use of precautionary allergen labeling (PAL) is not governed by regulation. PAL was initially identified as a judicious risk management measure to address instances of "unavoidable" cross-contact with priority food allergens during food processing. However, PAL has gradually been devalued in part due to overuse and inconsistent application by the food industry. Currently, most food products do not contain detectable allergen residue or contain only low concentrations of residue of the allergens declared using PAL; however, occasionally, high concentrations of allergen residue are reported, rendering it an ineffective risk communication tool for allergic consumers. In this context, several reasons exist that make the consumption of products bearing a PAL statement not advisable for people with food allergies. The main reason is that the risk is generally not correlated with the statement used by manufacturers. Because of the increased use of PAL on prepackaged food products, and to maximize food choices for allergic individuals, health care professionals increasingly advise some patients considered to be "not highly allergic" to consume products bearing a PAL statement. This article explains why the consumption of products with PAL is not advisable without having a full clinical evaluation and knowledge that an allergen risk assessment has been conducted. It also discusses the perspectives for a better use of PAL on the basis of the recent Food and Agricultural Organization/World Health Organization recommendations on food allergens.

Molecular allergy diagnostics in predicting oral cow's milk challenge outcome in Finnish children

Background: Oral food challenges (OFC) are required to diagnose food allergies but are resource-intensive. Objective: To reduce the need for OFCs, we sought to determine serum specific immunoglobulin E (sIgE) cutoff levels for cow's milk and its major allergens predicting oral milk challenge outcomes in children with suspected cow's milk allergy. Methods: A total of 135 Finnish children (median age, 1.8 years [range, 1.0-14.1 years]) with suspected cow's milk allergy underwent open OFC with unheated cow's milk. The sIgE levels to milk (f2), casein (Bos d 8), alpha-lactalbumin (Bos d 4), beta-lactoglobulin (Bos d 5), and bovine serum albumin (BSA) (Bos d 6) were measured and compared with the challenge outcomes. Results: Of the 135 OFCs, 5 were excluded from the study due to purely subjective symptoms. Of the 130 remaining OFCs, 98 results (75%) were positive. In a receiver operating characteristic analysis with 1-2-year-old children, no individual allergen sIgE had a better area under the curve than milk sIgE (0.824). A milk sIgE level > 6.30 kU/L gave 94% specificity and 33% sensitivity for positive OFCs. In 3-14-year-old children, a cutoff value >13.9 kU/L predicted a positive OFC result with 93% specificity and 25% sensitivity. Children with moderate-to-severe reactions had higher sIgE levels to milk, alpha-lactalbumin, and BSA than did children with mild reactions. Conclusion: Molecular allergy diagnostics did not improve the predictive performance compared with milk sIgE. The milk sIgE value that exceeds the cutoff for 95% specificity in combination with the clinical history may help to reduce the need for OFCs. The severity of an allergic reaction cannot reliably be predicted from sIgE measurements.

Management of IgE-mediated food allergy in the 21st century

The 21st century has seen the propulsion of research in the field of food allergy, which has driven real changes in the clinical approach. Allergen immunotherapy has been recommended for the active management of food allergy. Data have shown promising additional methods of treatment, including biologics. Efforts have been devoted to the risk stratification of food allergy and the standardization of the assessment of food-allergic severity. Alternative routes of administration of epinephrine are under investigation to minimize any mechanical issue and the fear of injections. Evidence-based guidelines have been published by the main international societies in the field of anaphylaxis and food allergy management and new updates are in preparation. In the coming years, treatment options that are currently in pre-clinical or early clinical evaluation will hopefully lead to safe and effective disease-modifying therapies for food allergy in clinical practice. The identification of reliable biomarkers and the standardization of definitions and measurement approaches, alongside a shared decision-making with patients and families, will be key for the development of personalized care and to help minimize the substantial burden of food allergy.

CD4+CD25+CD127loFOXP3+ cell in food allergy: Does it predict anaphylaxis?

BACKGROUND

Food allergy (FA), hence the incidence of food anaphylaxis, is a public health problem that has increased in recent years. There are still no biomarkers for patients with FA to predict severe allergic reactions such as anaphylaxis.

OBJECTIVE

There is limited information on whether regulatory T (Treg) cell levels are a biomarker that predicts clinical severity in cases presenting with FA, and which patients are at a greater risk for anaphylaxis.

METHODS

A total of 70 children were included in the study: 25 who had IgE-mediated cow's milk protein allergy (CMPA) and presented with non-anaphylactic symptoms (FA/A-), 16 who had IgE-mediated CMPA and presented with anaphylaxis (FA/A+) (a total of 41 FA cases), and a control group consisting of 29 children without FA. The study was conducted by performing CD4+CD25+CD127^loFOXP3+ cell flow cytometric analysis during resting at least 2 weeks after the elimination diet to FA subjects.

RESULTS

When the FA group was compared with healthy control subjects, CD4+CD25+CD127_loFOXP3+ cell rates were found to be significantly lower in the FA group (p < 0.001). When the FA/A- and FA/A+ groups and the control group were compared in terms of CD4+CD25+CD127^loFOXP3+ cell ratios, they were significantly lower in the FA/A- and FA/A+ groups compared to the control group (p < 0.001).

CONCLUSIONS

Although there was no significant difference between the FA/A+ group and the FA/A- group in terms of CD4+CD25+CD127^loFOXP3+ cells, our study is important, as it is the first pediatric study we know to investigate whether CD4+CD25+CD127^loFOXP3+ cells in FA predict anaphylaxis.

Nutritional Management of Children with Food Allergies

Purpose of the Review

The purpose of the review is to review the evidence for the nutritional management of paediatric food allergy and provide a practical approach for healthcare professionals working in this area.

Recent Findings

Dietary elimination remains the mainstay for management of food allergies in children. However, the elimination of food allergens increases the risk for growth faltering, micronutrient deficiencies and feeding difficulties. Breastmilk remains the ideal source of nutrition for infants, but when not available, the vast majority will tolerate an extensively hydrolysed formula, and rice hydrolysate has also been suggested as a suitable alternative. Only in severe cases, including anaphylaxis, eosinophilic oesophagitis and growth faltering, is an amino acid formula indicated. The early introduction of peanut and egg and avoiding the delay in the introduction of other allergens, when not already allergic, has been highlighted by recent studies.

Summary

Whilst the elimination of allergens increases the risk of developing poor growth, micronutrient deficiencies and feeding difficulties, optimal, early dietary input, including advice on active introduction of allergens and alternative feeds, ideally from a registered dietitian/nutritionist, may be prevent and improve outcomes.

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.

Four clinical phenotypes of cow’s milk protein allergy based on dairy product specific IgE antibody types in North China

Background

Cow’s milk protein allergy (CMPA) is a common allergy. Immunoglobulin E (IgE)-mediated cow’s milk allergy is associated with a high mortality risk and poor prognosis. The study aims to investigate whether there are different clinically CMPA phenotypes in China and to explore the association between CMPA phenotypes and specific IgE (sIgE) antibodies against different dairy products.

Methods

Serum sIgE against different animal milk and cow’s milk products and different milk components was measured by an allergen array. Four CMPA classifications were identified by the presence of serum sIgE: boiled milk-positive, yogurt-positive, buttermilk-positive, and raw milk-positive.

Results

Among the 234 participants included in the study, 9 were boiled milk sIgE-positive, 50 were yogurt sIgE-positive, 17 were buttermilk sIgE-positive, and 158 were only raw milk sIgE-positive. The boiled milk-positive group had the highest levels of raw milk sIgE and casein sIgE antibodies, followed sequentially by the yogurt-positive, buttermilk-positive, and raw milk-positive groups. The boiled milk group observed the highest levels of sIgE against raw milk, casein, α-lactalbumin, and β-lactoglobulin. These levels differed significantly from those in the other three groups. Allergic symptoms were distributed differently among the four study groups. The percentages of allergic patients with gastrointestinal tract symptoms in the above mentioned four groups ranged from high to low, and the percentages of patients with skin symptoms in the four groups ranged from low to high, respectively.

Conclusion

Based on dairy product sIgE antibody levels associated with different milk components and various clinical allergic symptom tendencies, we could distinguish four CMPA phenotypes.

Biomarkers in oral immunotherapy

Food allergy (FA) is a global health problem that affects a large population, and thus effective treatment is highly desirable. Oral immunotherapy (OIT) has been showing reasonable efficacy and favorable safety in most FA subjects. Dependable biomarkers are needed for treatment assessment and outcome prediction during OIT. Several immunological indicators have been used as biomarkers in OIT, such as skin prick tests, basophil and mast cell reactivity, T cell and B cell responses, allergen-specific antibody levels, and cytokines. Other novel indicators also could be potential biomarkers. In this review, we discuss and assess the application of various immunological indicators as biomarkers for OIT.

Risk factors for severe reactions in food allergy: Rapid evidence review with meta-analysis

This rapid review summarizes the most up to date evidence about the risk factors for severe food-induced allergic reactions. We searched three bibliographic databases for studies published between January 2010 and August 2021. We included 88 studies and synthesized the evidence narratively, undertaking meta-analysis where appropriate. Significant uncertainties remain with respect to the prediction of severe reactions, both anaphylaxis and/or severe anaphylaxis refractory to treatment. Prior anaphylaxis, an asthma diagnosis, IgE sensitization or basophil activation tests are not good predictors. Some molecular allergology markers may be helpful. Hospital presentations for anaphylaxis are highest in young children, yet this age group appears at lower risk of severe outcomes. Risk of severe outcomes is greatest in adolescence and young adulthood, but the contribution of risk taking behaviour in contributing to severe outcomes is unclear. Evidence for an impact of cofactors on severity is lacking, although food-dependent exercise-induced anaphylaxis may be an exception. Some medications such as beta-blockers or ACE inhibitors may increase severity, but appear less important than age as a factor in life-threatening reactions. The relationship between dose of exposure and severity is unclear. Delays in symptom recognition and anaphylaxis treatment have been associated with more severe outcomes. An absence of prior anaphylaxis does not exclude its future risk.

Tolerance to sterilised cow's milk in patients with eosinophilic oesophagitis triggered by milk

BACKGROUND

Cow's milk protein is the main food trigger for eosinophilic oesophagitis (EoE) in children and adults and should be continuously avoided once identified as such.

AIMS

To evaluate tolerance of sterilised cow's milk (boiled instead of UHT processing) with regard to maintenance of EoE remission, health-related quality of life (HRQoL), nutritional intake and allergic sensitisation in patients of all ages with milk-triggered EoE METHODS: We prospectively recruited patients in whom cow's milk was demonstrated to trigger EoE after an empirical food elimination diet-based study. They were given 200 ml of sterilised cow's milk twice daily for 8 weeks. Endoscopic assessment, peak eosinophil counts, oesophageal-related symptoms, HRQoL, blood eosinophils, eosinophil cationic protein (ECP), skin prick test and serum total and specific immunoglobulin E (IgE) to major milk proteins were monitored before and after sterilised milk intake.

RESULTS

Eighteen patients (13 male) in EoE remission underwent a sterilised milk challenge. Twelve maintained EoE remission (<15 eos/hpf) while EoE recurred in the remainder. Endoscopic appearances deteriorated in non-tolerant patients. HRQoL scored well at baseline and was maintained among patients tolerant to sterilised milk, but deteriorated in reactive ones. No significant changes in blood eosinophil count, ECP, tryptase or total and milk-specific IgE serum levels were observed from baseline. However, cow's milk-specific IgE increased slightly in non-tolerant patients. Clinical and histological remission were maintained in patients who regularly consumed sterilised milk for 1 year.

CONCLUSION

Sterilised milk did not trigger EoE in two-thirds of patients with documented milk-induced EoE, in either the short or long term.

Effect of thermal processing on the antigenicity of allergenic milk, egg and soy proteins

The detection of allergenic proteins and the influence of processing on the structure and antigenicity of these proteins are relevant topics. Using commercial enzyme-linked immunosorbent assay kits, this study aimed to evaluate the degradation profiles of milk, egg and soy proteins during the processing of semisweet biscuits. The formulations were baked under different conditions according to a complete factorial experiment that included a three-level temperature factor and a six-level time factor. β-lactoglobulin and egg white proteins were severely degraded, the degradation of casein was intermediate, and soy proteins were the most stable. Complete allergen protein degradation was found under only the extreme baking conditions, which resulted in products that were not sensorily acceptable. Residual levels of the proteins were detected after baking, indicating that this thermal processing reduced but did not eliminate the antigenicity of these proteins; thus, baking cannot be considered a strategy to protect allergic consumers.

Prospective evaluation of tolerance to unheated milk-boiled egg after baked milk-egg tolerance under 2 years

BACKGROUND

The time to acquisition of tolerance to unheated milk and regular egg after achievement of tolerance to baked goods is not known.

OBJECTIVE

To determine the time to acquisition of unheated-milk-regular-egg tolerance, after the tolerance of the baked forms, in children younger than 2 years.

METHODS

An initial oral food challenge with baked milk (BM) and baked egg (BE) was performed on patients who were reactive to unheated milk-regular egg, respectively. Patients who were BM-BE tolerant were offered unheated-milk-regular-egg challenges, and patients who were BM-BE reactive were offered BM-BE challenges at an average of 3-month intervals. Food-induced atopic dermatitis was included.

RESULTS

Thirty-six children with unheated-milk allergy (median age, 7.3 months [interquartile range (IQR), 6.0-13.5]) and 65 with regular-egg allergy (median age, 7 months [IQR, 5.8-11.0]) were included. Seven of 13 children who were BM tolerant acquired unheated-milk tolerance after a median 4.0 months (IQR, 2.0-7.0). Twelve of 23 children who were BM reactive acquired unheated-milk tolerance after a median 5.0 months (IQR, 3.0-8.0) after BM tolerance. Twenty-one of 29 children who were BE tolerant acquired regular-egg tolerance after a median 3.0 months (IQR, 1.0-6.0). Sixteen of 36 children who were BE reactive acquired regular-egg tolerance after a median 4.0 months (IQR, 2.0-6.8) after BE tolerance.

CONCLUSION

Different tolerance rates were determined for baked products at different time points in the first 2 years of life. Unheated-milk-regular-egg allergy resolved in up to 65.5% and 75.5% of cases, respectively, in an average 4 to 5 months after acquisition of BM-BE tolerance. Baked-milk-baked-egg tolerance may be regarded as a precursor of tolerance.

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

Background

Cow's milk is a food allergen of public health importance both in the United States and globally. Its natural history and epidemiology have been most studied among infants and young children, but the public health burden it places on adults and older pediatric populations remains unclear. This study comprehensively characterizes the US population-level burden of cow's milk allergy (CMA), including its prevalence, severity, health care utilization, psychosocial impact, natural history, and other associated factors-including ability to tolerate extensively heated milk products-within a large, nationally-representative survey sample of US households.

Methods

A cross-sectional survey was administered via web and telephone. Population level inference was based on data collected from participants recruited from National Opinion Research Center (NORC) at the University of Chicago's probability-based AmeriSpeak panel. Established dual-sample complex survey calibration methods were used to augment this sample with additional participants recruited through Survey Sampling International to increase the precision of the resulting estimates. In total, surveys were administered to a nationally representative sample of 51 819 US households from October 1, 2015, through September 31, 2016. Self-report responses from 40 453 adults and parent-proxy report for 38 408 children were analyzed.

Results

Analyzing survey responses from 78 851 individuals, an estimated 4.7% (95% CI, 4.4%-4.9%) of the US population reported current CMA, whereas 1.9% (95% CI, 1.8%-2.1%) met symptom-report criteria for convincing IgE-mediated allergy. An estimated 0.9% (95% CI, 0.8%-1.0%) had CMA that met convincing symptom-report criteria and was physician diagnosed. Female and White respondents were more likely to report outgrowing CMA relative to males and those reporting other races and ethnicities. Individuals with CMA who reported tolerance to baked milk products were less likely to report severe reaction histories (33.5% vs 42.7%; p = .03), a lifetime history of food allergy-related emergency department visits (43.4% vs. 55.8%; p = .005), and treating a milk-allergic reaction with epinephrine (10.6 vs. 18.9%; p = .003). These individuals also exhibited less psychosocial burden on the validated Food Allergy Independent Measure (FAIM) than their counterparts with CMA who were allergic to baked forms of milk.

Conclusion

These data indicate a discrepancy in reported rates of allergy to cow's milk among the US general population ranging from approximately 1 in 20 with reported CMA to fewer than 1 in 50 with physician-confirmed CMA. However, they suggest a substantial population-level burden of CMA, including substantial healthcare utilization, psychosocial burden and nutritional impacts-particularly among the approximately 30% of individuals with CMA who cannot tolerate baked forms of milk.

A solid-state electrochemiluminescence aptasensor for β-lactoglobulin using Ru-AuNP/GNP/Naf nanocomposite-modified printed sensor

An electrochemiluminescence (ECL) aptasensor for the detection of the milk protein allergen β-lactoglobulin (β-LG) using nanocomposite as luminophore was fabricated. The Ru-AuNPs/GNP/Naf complex was formed by combining the Rubpy₃²⁺-AuNPs complex (Ru-AuNPs), prepared by modifying the negatively charged surface of gold nanoparticles (AuNPs) with positively charged Rubpy₃²⁺ through electrostatic interactions and the graphene nanoplatelets-Nafion (GNP/Naf) at a ratio of 2:1. The nanocomposite was coated on the surface of the screen-printed electrode (SPCE) through the film-forming properties of Nafion. A layer of chitosan (CS) was coated onto this modified electrode, and later amine-terminated β-LG aptamers were covalently attached to the CS/Ru-AuNP/GNP/Naf via glutaraldehyde (GLUT) cross-linking. When β-LG was incubated with the aptasensor, a subsequent decrease in ECL intensity was recorded. Under the optimal conditions, the ECL intensity of the aptasensor changed linearly with the logarithmic concentration of β-LG, in the range 0.1 to 1000 pg/ml, and the detection limit was 0.02 pg/mL (3σ/m). The constructed aptasensor displayed simple and fast determination of β-LG with excellent reproducibility, stability, and high specificity. Additionally, the proposed ECL aptasensor displayed high recoveries (92.5-112%) and low coefficients of variation (1.6-7.8%), when β-LG fortified samples were analyzed. Integrating Ru-AuNPs/GNP/Naf nanocomposite in the ECL aptasensor paves the way towards a cost-effective and sensitive detection of the milk allergen β-LG.

Introduction of Heated Cow's Milk Protein in Challenge-Proven Cow's Milk Allergic Children: The iAGE Study

The introduction of baked milk products in cow’s milk (CM) allergic children has previously been shown to accelerate induction tolerance in a selected group of children. However, there is no standardized baked milk product on the market. Recently, a new standardized, heated and glycated cow’s milk protein (HP) product was developed. The aim of this study was to measure safety and tolerability of a new, well characterized heated CM protein (HP) product in cow’s milk allergic (CMA) children between the age of 3 and 36 months. The children were recruited from seven clinics throughout The Netherlands. The HP product was introduced in six incremental doses under clinical supervision. Symptoms were registered after introduction of the HP product. Several questionnaires were filled out by parents of the children. Skin prick tests were performed with CM and HP product, sIgE to CM and α-lactalbumin (Bos d4), β-lactoglobulin (Bos d5), serum albumin (Bos d 6), lactoferrin (Bos d7) and casein (Bos d8). Whereas 72% percent (18 out of 25) of the children tolerated the HP product, seven children experienced adverse events. Risk factors for intolerance to the HP product were higher skin prick test (SPT) histamine equivalent index (HEP) results with CM and the HP product, higher specific IgE levels against Bos d4 and Bos d8 levels and Bos d5 levels. In conclusion, the HP product was tolerated by 72% of the CM allergic children. Outcomes of SPT with CM and the HP product, as well as values of sIgE against caseins, α-lactalbumin, and β-lactoglobulin may predict the tolerability of the HP product. Larger studies are needed to confirm these conclusions.

Precision medicine in the allergy clinic: the application of component resolved diagnosis

INTRODUCTION

A precise diagnosis is key for the optimal management of allergic diseases and asthma. In vivo or in vitro diagnostic methods that use allergen extracts often fail to identify the molecules eliciting the allergic reactions.

AREAS COVERED

Component-resolved diagnosis (CRD) has solved most of the limitations of extract-based diagnostic procedures and is currently valuable tool for the precision diagnosis in the allergy clinic, for venom and food allergy, asthma, allergic rhinitis, and atopic dermatitis. Its implementation in daily practice facilitates: a) the distinction between genuine multiple sensitizations and cross-reactive sensitization in polysensitized patients; b) the prediction of a severe, systemic reaction in food or insect venom allergy; c) the optimal selection of allergen immunotherapy based on the patient sensitization profile. This paper describes its main advantages and disadvantages, cost-effectiveness and future perspectives.

EXPERT OPINION

The diagnostic strategy based on CRD is part of the new concept of precision immunology, which aims to improve the management of allergic diseases.

Predictive Factors for Oral Immune Modulation in Cow Milk Allergy

Aim: The present study analyzed clinical and biological factors that might predict achievement of tolerance in patients with IgE-mediated cow milk allergy (CMA). Method: Seventy patients with IgE-mediated CMA (44.24 ± 24.16 months) were included in the study. The patients were evaluated clinically through skin prick test and sIgE to whole milk, casein, beta-lactoglobulin and alpha-lactalbumin. An eviction diet of 6 months was established, followed by oral food challenge test (OFC) and oral immunotherapy (OIT) with baked milk for 6 months. The tolerance was assessed after 2 years follow up. Results: Thirty percent of patients presented anaphylaxis of different degrees of severity as first manifestation of CMA. Sixty-two patients followed OIT or an accelerated reintroduction of milk. Ten patients (14.28%) did not obtain tolerance to milk within 2 years. A larger wheal in SPT and higher sIgE to milk, casein and betalactoglobulin were noted in patients with positive OFC. A basal level of <2.5 kU/l for sIgE to milk and <11.73 kU/l for sIgE to caseins predicted the occurrence of tolerance in patients with all types of clinical manifestations, including anaphylaxis. Conclusion: Basal levels of sIgE to milk and casein may help to identify patients that could become tolerant to milk.

Food allergen ladders: A need for standardization

INTRODUCTION

The process of gradually reintroducing food allergens into an individual's diet is referred to as food allergen "ladders". There remain many questions regarding the foods chosen, structure and composition of the ladder, and medical and safety considerations. The COVID-19 pandemic has propelled us into an era where medicine is increasingly practiced via online platforms, highlighting the need for standardized food allergen ladder approaches for successful and safe introduction of food allergens.

METHODS

We performed a search of currently published food allergen ladders and obtained published information and clinical expertise to summarize current knowledge and suggest future standardized approaches for using food allergen ladders.

RESULTS

There are currently a limited number of published milk, egg, wheat, and soy ladders. We suggest the following points should be considered when developing food ladders: (1) Food allergen: dose, time, and temperature of heating of the food allergen, simplicity of the ladder and recipes, the possible role of the wheat matrix, and testing for allergenic protein levels to standardize doses; (2) Nutritional factors: health and nutritional value of the foods in the ladder, taste, texture, and cultural appropriateness of foods should be considered; and (3) Medical aspects: consideration of which patients are safe to undergo ladders outside of the clinical setting, other safety aspects and risk factors for severe reactions, number of days suggested per steps, and availability and provision of rescue medication. Written instructions and recipes should be provided to families who wish to use food allergen ladders.

DISCUSSION

Food allergen ladders used for gradual reintroduction of food allergens into a food allergic individual's diet are increasingly being used internationally. Standardization regarding the foods included in the ladder and medical considerations are required to practice patient-centered care, best assist patients and families, and ensure safety.

Threshold of Reactivity and Tolerance to Precautionary Allergen-Labelled Biscuits of Baked Milk- and Egg-Allergic Children

Extremely sensitive food-allergic patients may react to very small amounts of allergenic foods. Precautionary allergen labelling (PAL) warns from possible allergenic contaminations. We evaluated by oral food challenge the reactivity to a brand of PAL-labelled milk- and egg-free biscuits of children with severe milk and egg allergy. We explored the ability of proteomic methods to identify minute amounts of milk/egg allergens in such biscuits. Traces of milk and/or egg allergens in biscuits were measured by two different liquid-chromatography-mass spectrometry methods. The binding of patient’s serum with egg/milk proteins was assessed using immunoblotting. None of the patients reacted to biscuits. Egg and milk proteins were undetectable with a limit of detection of 0.6 µg/g for milk and egg (method A), and of 0.1 and 0.3 µg /g for milk and egg, respectively (method B). The immunoblots did not show milk/egg proteins in the studied biscuits. Milk/egg content of the biscuits is far lower than 4 µg of milk or egg protein per gram of product, the minimal doses considered theoretically capable of causing reactions. With high sensitivity, proteomic assessments predict the harmlessness of very small amount of allergens in foods, and can be used to help avoiding unnecessary PAL.

Elevated Cow's Milk-Specific IgE Levels Prior to Oral Immunotherapy Decrease the Likelihood of Reaching the Maintenance Dose

BACKGROUND

Food desensitization via oral immunotherapy (OIT) is gaining acceptance in clinical practice. Owing to adverse reactions, the duration of the buildup phase until a maintenance dose is achieved may be prolonged, and in a minority of cases, OIT is stopped.

OBJECTIVE

We aimed to assess factors associated with the probability of reaching the maintenance dose in cow's milk (CM) OIT.

METHODS

We collected data from patients undergoing CM OIT at the Montreal Children's Hospital, BC Children's Hospital, and Hospital for Sick Children. We compared univariable and multivariable Cox regressions to evaluate sociodemographic factors, comorbidities, clinical characteristics, and biomarkers at study entry associated with the likelihood of reaching a maintenance dose of 200 mL of CM.

RESULTS

Among 69 children who reached 4 mL of milk, the median age was 12 years (interquartile range, 9-15 years); 59% were male. Median duration of buildup phase from 4 to 200 mL was 24.0 weeks (interquartile range, 17.7-33.4 weeks). After adjusting for age and sex, higher baseline levels of specific IgE antibodies for α-lactalbumin (hazard ratio [HR] = 0.80; 95% confidence interval [CI], 0.67-0.95), β-lactoglobulin (HR = 0.86; 95% CI, 0.76-0.98), casein (HR = 0.82; 95% CI, 0.72-0.94), and total CM (HR = 0.79; 95% CI, 0.65-0.97) were associated with a decreased probability of reaching maintenance. In addition, for every 10-mL increase in CM tolerated at entry challenge, the probability of reaching maintenance increased by 10%.

CONCLUSIONS

The data suggest that higher levels of CM-specific IgE decreased the likelihood of reaching maintenance, whereas an increased cumulative CM dose at entry challenge increased the likelihood. Assessing these factors before therapy may assist in predicting the success of CM OIT.

Efficacy and Safety of Baked Milk Oral Immunotherapy in Children with Severe Milk Allergy: A Randomized, Double-blind, Placebo-controlled Phase 2 Trial

BACKGROUND

Cow's milk allergy is the most common food allergy in young children and has no current treatment. Oral immunotherapy studies to date have shown efficacy but high rates of adverse reactions.

OBJECTIVE

We sought to evaluate the safety and efficacy of baked milk oral immunotherapy (BMOIT) in baked milk allergic children.

METHODS

Participants (3-18 years) were randomized to receive BMOIT or placebo for 12 months. Efficacy was assessed by double-blind placebo-controlled food challenge after 12 months of treatment. Safety, quality of life, and mechanistic parameters were also evaluated.

RESULTS

11/15 (73%) of the BMOIT participants reached the primary endpoint, tolerating 4044 mg of baked milk protein after 12 months of OIT, compared to 0/15 (0%) on placebo. The median maximal tolerated dose (MTD) and median change from baseline was significantly higher in the BMOIT group compared to placebo (median MTD 4044mg vs 144mg; p=0.001; median change in MTD of 3900mg vs 0mg, p=0.0001). Dose-related reactions were common but >95% in both groups were mild. There was no significant change in CM- or beta lactoglobulin-IgE from baseline for either group. CM-sIgG4 did significantly increase and casein IgE decreased in the BMOIT group. For proxy-reported food allergy quality of life, there was a significant difference in the emotional impact domain only with more improving while on placebo compared BMOIT. The majority of children and adolescents in the BMOIT group directly reported improvement in at least one domain.

CONCLUSION

BMOIT was well tolerated and induced a substantial level of desensitization after 12 months of treatment.

Oral Immunotherapy for Food-Allergic Children: A Pro-Con Debate

The prevalence of food allergy has increased in recent years, especially in children. Allergen avoidance, and drugs in case of an allergic reaction, remains the standard of care in food allergy. Nevertheless, increasing attention has been given to the possibility to treat food allergy, through immunotherapy, particularly oral immunotherapy (OIT). Several OIT protocols and clinical trials have been published. Most of them focus on children allergic to milk, egg, or peanut, although recent studies developed protocols for other foods, such as wheat and different nuts. OIT efficacy in randomized controlled trials is usually evaluated as the possibility for patients to achieve desensitization through the consumption of an increasing amount of a food allergen, while the issue of a possible long-term sustained unresponsiveness has not been completely addressed. Here, we evaluated current pediatric OIT knowledge, focusing on the results of clinical trials and current guidelines. Specifically, we wanted to highlight what is known in terms of OIT efficacy and effectiveness, safety, and impact on quality of life. For each aspect, we reported the pros and the cons, inferable from published literature. In conclusion, even though many protocols, reviews and meta-analysis have been published on this topic, pediatric OIT remains a controversial therapy and no definitive generalized conclusion may be drawn so far. It should be an option provided by specialized teams, when both patients and their families are prone to adhere to the proposed protocol. Efficacy, long-term effectiveness, possible role of adjuvant therapies, risk of severe reactions including anaphylaxis or eosinophilic esophagitis, and impact on the quality of life of both children and caregivers are all aspects that should be discussed before starting OIT. Future studies are needed to provide firm clinical and scientific evidence, which should also consider patient reported outcomes.

Oral Immunotherapy for Children with Cow's Milk Allergy

Cow's milk allergy (CMA) is one of the most common IgE-dependent food allergies in children. Some children develop severe and persistent CMA, with near-fatal reactions after exposure to trace amounts of cow's milk (CM). Because milk and dairy products are included in various processed food products, it is difficult to completely remove milk, which negatively affects the quality of life of children with CMA. Oral immunotherapy (OIT) can alleviate food allergen-induced anaphylaxis under continuous ingestion of a little of the causative food. Children with severe CMA may benefit from OIT, but the treatment requires a long time and poses a risk of anaphylaxis. Moreover, in recent years, new therapies, including omalizumab, sublingual immunotherapy, and epicutaneous immunotherapy, have played the role of optional OIT. In this review, we present the current methods of and other attempts at OIT, and discuss OIT for safely treating CMA.

Factors associated with outcome of egg allergy 1 year after oral food challenge: A good baseline quality of life may be beneficial

BACKGROUND

Safely liberalizing the diet to include an allergenic food may accelerate resolution of food allergy. The outcome of liberalization, however, varies among patients.

METHODS

We conducted a prospective observational study to identify factors associated with outcome for egg allergy 1 year after oral food challenge (OFC). We enrolled children <72 months old who had egg allergy and underwent OFC for determination of the safe intake quantity of egg allergen. Each child's baseline clinical background was recorded. Caregivers used the Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF) to assess their children's QoL. Dietary advice based on the OFC result was provided to support safe egg consumption. At 1 year after OFC, the quantity of egg each child safely consumed in daily life was surveyed. We classified the outcome as Successful (Group S) if the quantity increased during the 1 year, or as Unsuccessful (Group U) if it did not. Factors associated with the outcome were investigated by multivariate logistic regression analysis.

RESULTS

A total of 93 children were enrolled, and after 1 year, 57 finished in Group S and 36 in Group U. The mean FAQLQ-PF score at baseline was significantly lower (ie, a better QoL) in Group S than in Group U. Multivariate logistic regression analysis identified a good QoL and absence of comorbid asthma or atopic dermatitis as factors predicting a favorable outcome.

CONCLUSION

QoL may affect food allergy outcome. Intervention focusing on the QoL may promote outgrowing of food allergies.

The Challenge of Home Allergen Re-introductions Using the Ladder Approach in Children With Non-IgE Mediated Gastrointestinal Food Allergy

Background: Oral food challenges remain the most reliable method for allergy confirmation. Although consensus guidelines have been published to unify Immunoglobulin E (IgE)-mediated challenges, this does not exist for non-IgE mediated gastrointestinal allergies outside of Food Protein Induced Enterocolitis Syndrome. We therefore set out to establish the use of home introduction protocols (HIP) for confirmation of food allergy for milk, soya, egg and wheat using a ladder approach in children with non-IgE mediated allergy.

Materials and Methods: Patients with suspected non-IgE mediated gastrointestinal allergies (0–16 years) were recruited following symptom improvement on an elimination diet. All children had skin prick or specific IgE tests to rule out IgE-mediated allergies prior to suggestion the HIP. Number of trials and outcome was documented. HIPs were developed using a published ladder approach for cow's milk as baseline and final dose was calculated based on guidelines for food protein induced enterocolitis syndrome and portions for age from the National Diet and Nutrition Survey. First foods were baked/highly processed and every 4th day patients moved to a more unprocessed/unheated food.

Results: From 131 recruited patients, 117 (89.3%) followed the HIP for food allergens. No adverse events were documented. In more than 50% of cases one attempt at the HIP was sufficient to establish allergy status, but many required 2–5 attempts before the outcome was clear. About half of the children were fully tolerant to foods they initially eliminated: 36, 26 and 30% were partially tolerant to milk, soya, and egg and only 15% achieved partial tolerance to wheat. Wheat was the allergen introduced earliest, followed by soya, cow's milk and egg.

Conclusions: This study indicates that home HIPs are safe in non-IgE mediated gastrointestinal food allergy and that the ladder approach may be useful in re-introducing allergens in children at home with non-IgE mediated gastrointestinal allergies. From this study we can also conclude that tolerance to processed/baked allergens was observed in many children. Further studies should be performed on the HIP and ideally reintroduction should occur pre-defined time intervals.