Allergy to goat's and sheep's milk in a population of cow's milk-allergic children treated with oral immunotherapy

Higher Potential Sensitization of Cow αS1-Casein over Goat αS1-Casein in a Mouse Model due to Enhanced Dendritic Cell Uptake and Activation

Cow's milk allergy is a common food allergy, with the milk protein αS1-casein being a major allergen. This study aimed to investigate differences in sensitization between cow and goat αS1-CN. Cow and goat αS1-CN were labeled with fluorescent dyes and given to mice sensitized with cholera toxin adjuvant. Both proteins reached immune organs, suggesting no major difference in digestion. However, compared with goat αS1-CN, cow αS1-CN is more readily taken up by dendritic cells, inducing dendritic cell maturation. Furthermore, cow αS1-CN can more effectively induce the generation of Th2 cells, leading to a higher production of specific IgE. In a Caco-2/RBL-2H3 cell model, cow αS1-CN caused more mast cell degranulation and loss of epithelial barrier integrity than goat αS1-CN. In summary, this study found differences in immune responses between cow and goat milk αS1-CN. Cow αS1-CN elicited stronger dendritic cell and Th2 responses, leading to increased mast cell degranulation.

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.

Cross-reactive epitopes and their role in food allergy

Allergenic cross-reactivity among food allergens complicates the diagnosis and management of food allergy. This can result in many patients being sensitized (having allergen-specific IgE) to foods without exhibiting clinical reactivity. Some food groups such as shellfish, fish, tree nuts, and peanuts have very high rates of cross-reactivity. In contrast, relatively low rates are noted for grains and milk, whereas many other food families have variable rates of cross-reactivity or are not well studied. Although classical cross-reactive carbohydrate determinants are clinically not relevant, α-Gal in red meat through tick bites can lead to severe reactions. Multiple sensitizations to tree nuts complicate the diagnosis and management of patients allergic to peanut and tree nut. This review discusses cross-reactive allergens and cross-reactive carbohydrate determinants in the major food groups, and where available, describes their B-cell and T-cell epitopes. The clinical relevance of these cross-reactive B-cell and T-cell epitopes is highlighted and their possible impact on allergen-specific immunotherapy for food allergy is discussed.

Safe food through better labelling; a robust method for the rapid determination of caprine and bovine milk allergens

Accidental milk cross-contamination is one of the most common causes for costly food recalls. Yet, quantifying trace-levels of allergen is time-consuming and current methods are not adapted for routine analyses making quality control for trace-level allergen content impractical. This perpetuates voluntary "may-contain" statements that are unhelpful for people suffering from food allergies. Here, we developed a rapid LC-MS method enabling milk allergen quantification by comparing all tryptic-peptides of major milk allergens. The bovine-specific αS-2 casein peptide and allergen-epitope NAVPITPTLNR provided excellent performance in sensitivity (LOD 1 mg.kg^-1; LOQ 2 mg.kg^-1) across various dairy products, good recovery rates in baked croissants (77% with a 10% inter-day RSD) and a linear range of 2-2,000 mg.kg^-1. The method can be used for routine determination of trace-contamination with bovine milk allergen and the adulteration of high-value caprine dairy products with lower-value bovine milk products, protecting consumer trust and the growing population suffering from food allergies.

Camel Milk Cannot Prevent the Development of Cow's Milk Allergy-A Study in Brown Norway Rats

SCOPE

Currently there are no specific recommendations for the use of any particular infant formula in the prevention of cow's milk allergy (CMA). Recently, there has been an increasing interest in alternative infant formulas based on milk proteins from other sources than the cow, including milk from other mammalians such as goat, sheep, donkey, horse, and camel. Whereas these have been studied for their usability in CMA management, there are no studies of their CMA preventive capacity. Thus, the aim of this study is to evaluate whether camel milk can prevent CMA and vice versa.

METHODS AND RESULTS

The capacity of camel milk in preventing CMA and vice versa is evaluated in a well-established prophylactic Brown Norway rat model. IgG1, IgE, and IgA responses, allergy elicitation, intestinal and mLN gene expression, and protein uptake are analyzed. The study demonstrates that camel and cow's milk in general has an insignificant cross-preventive capacity. Yet, whereas cow's milk is shown to have a low transient capacity to prevent sensitization and clinically active camel milk allergy, camel milk does not show this effect for CMA.

CONCLUSIONS

This study suggests that due to lack of cross-tolerance camel milk cannot be used for CMA prevention.

Alternatives to Cow’s Milk-Based Infant Formulas in the Prevention and Management of Cow’s Milk Allergy

Cow’s milk-based infant formulas are the most common substitute to mother’s milk in infancy when breastfeeding is impossible or insufficient, as cow’s milk is a globally available source of mammalian proteins with high nutritional value. However, cow’s milk allergy (CMA) is the most prevalent type of food allergy among infants, affecting up to 3.8% of small children. Hypoallergenic infant formulas based on hydrolysed cow’s milk proteins are commercially available for the management of CMA. Yet, there is a growing demand for more options for infant feeding, both in general but especially for the prevention and management of CMA. Milk from other mammalian sources than the cow, such as goat, sheep, camel, donkey, and horse, has received some attention in the last decade due to the different protein composition profile and protein amino acid sequences, resulting in a potentially low cross-reactivity with cow’s milk proteins. Recently, proteins from plant sources, such as potato, lentil, chickpeas, quinoa, in addition to soy and rice, have gained increased interest due to their climate friendly and vegan status as well as potential lower allergenicity. In this review, we provide an overview of current and potential future infant formulas and their relevance in CMA prevention and management.

Massive hematemesis and melena stool: A case report of unusual manifestation of Cow's milk protein intolerance

Cow’s milk protein intolerance (CMPI) is a common condition that causes gastrointestinal bleeding in the first year of life. It is the most common cause of chronic blood loss and anemia; however, severe massive hematemesis is an uncommon condition. Herein, we present a case of severe massive hematemesis with melena stool in a six-month-old boy with cow’s milk protein intolerance. In this case, we described management used in poor developing countries.

Allergen Risk Assessment for Specific Allergy to Small Ruminant's Milk: Development of Sensitive Immunoassays to Detect Goat's and Sheep's Milk Contaminations in Dairy Food Matrices

Despite a high level of sequence identity between cow's, goat's, and sheep's milk (CM, GM, and SM, respectively) proteins, some patients tolerant to CM are allergic to GM and SM. In most cases, this specificity is due to the presence of IgE antibodies that bind only to caprine and ovine caseins. The patients may then develop severe allergic reactions after ingestion of CM products contaminated with low amounts of GM or SM. We thus aimed to develop an assay able to detect traces of caprine/ovine β-caseins in different food matrices, irrespective of the presence of the bovine homolog. We produced monoclonal antibodies (mAbs) specific to caprine caseins in mice tolerized to the bovine whole casein then sensitized to the caprine whole casein. In order to develop a two-site immunometric assay, we selected mAbs that could discriminate the caprine β-casein from its bovine homolog. Characteristics and performances of two tests were determined with various dairy products. Results were analyzed in relation with the IgE-immunoreactivity of the food matrices, thanks to sera from CM, GM/SM allergic patients. Our two-site immunometric assays demonstrated a high sensitivity with a detection limit of 1.6–3.2 ng/mL of caprine and ovine β-caseins. The tests were able to detect contaminations of GM in CM at the ppm level. Heat-treatment, ripening and coagulation processes, usually applied to dairy products that exhibit a very high IgE-immunoreactivity, did not impair the test sensitivity. These quantitative assays could then be useful for the risk assessment of food products potentially contaminated with GM and SM in order to prevent adverse reactions in patients specifically allergic to these milks.

Clinical Relevance of Cross-Reactivity in Food Allergy

The diagnosis and management of food allergy is complicated by an abundance of homologous, cross-reactive proteins in edible foods and aeroallergens. This results in patients having allergic sensitization (positive tests) to many biologically related foods. However, many are sensitized to foods without exhibiting clinical reactivity. Although molecular diagnostics have improved our ability to identify clinically relevant cross-reactivity, the optimal approach to patients requires an understanding of the epidemiology of clinically relevant cross-reactivity, as well as the food-specific (degree of homology, protein stability, abundance) and patient-specific factors (immune response, augmentation factors) that determine clinical relevance. Examples of food families with high rates of cross-reactivity include mammalian milks, eggs, fish, and shellfish. Low rates are noted for grains (wheat, barley, rye), and rates of cross-reactivity are variable for most other foods. This review discusses clinically relevant cross-reactivity related to the aforementioned food groups as well as seeds, legumes (including peanut, soy, chickpea, lentil, and others), tree nuts, meats, fruits and vegetables (including the lipid transfer protein syndrome), and latex. The complicating factor of addressing co-allergy, for example, the risks of allergy to both peanut and tree nuts among atopic patients, is also discussed. Considerations for an approach to individual patient care are highlighted.

Consensus statement on the epidemiology, diagnosis, prevention, and management of cow's milk protein allergy in the Middle East: a modified Delphi-based study

BACKGROUND

This study aimed to develop an expert consensus regarding the epidemiology, diagnosis, and management of cow's milk protein allergy (CMPA) in the Middle East.

METHODS

A three-step modified Delphi method was utilized to develop the consensus. Fifteen specialized pediatricians participated in the development of this consensus. Each statement was considered a consensus if it achieved an agreement level of ≥ 80%.

RESULTS

The experts agreed that the double-blind placebo-controlled oral challenge test (OCT) should be performed for 2-4 weeks using an amino acid formula (AAF) in formula-fed infants or children with suspected CMPA. Formula-fed infants with confirmed CMPA should be offered a therapeutic formula. The panel stated that an extensively hydrolyzed formula (eHF) is indicated in the absence of red flag signs. At the same time, the AAF is offered for infants with red flag signs, such as severe anaphylactic reactions. The panel agreed that infants on an eHF with resolved symptoms within 2-4 weeks should continue the eHF with particular attention to the growth and nutritional status. On the other hand, an AAF should be considered for infants with persistent symptoms; the AAF should be continued if the symptoms resolve within 2-4 weeks, with particular attention to the growth and nutritional status. In cases with no symptomatic improvements after the introduction of an AAF, other measures should be followed. The panel developed a management algorithm, which achieved an agreement level of 90.9%.

CONCLUSION

This consensus document combined the best available evidence and clinical experience to optimize the management of CMPA in the Middle East.

Anaphylaxis to goat/sheep's milk in a 4-year-old boy tolerant to cow's milk

Immune-mediated reactions to dairy products may vary depending on the mammalian source. We present a case of anaphylaxis to goat/sheep's milk with tolerance to cow's milk. A 4-year-old boy of Eastern European descent presented with gastrointestinal and respiratory symptoms within minutes after eating a goat/sheep's milk-derived food product. The tryptase level measured 1 hour post initial symptoms and 1 month after the allergic reaction were 14.6 µg/L and 5.1 µg/L, respectively (norm: 0.0-13.5 µg/L), confirming the diagnosis of anaphylaxis. A skin prick test performed 1 month after the reaction was highly positive for goat/sheep's milk, but negative for cow's milk. Skin prick tests may establish a life-threatening goat/sheep's milk allergy. Goat/sheep's milk allergy should always be considered in cow's milk-tolerant patients who present with an allergic reaction to dairy products, or when undergoing/have completed of oral immunotherapy for cow's milk allergy.

Goat's milk anaphylaxis in a cow's milk tolerant child

Goat's milk (GM) allergy commonly occurs together with cow's milk (CM) allergy due to cross-reactivity between highly homologous proteins. We present an unusual case of GM anaphylaxis in a CM tolerant child.

Oral immunotherapy for food allergy: A Spanish guideline. Immunotherapy egg and milk Spanish guide (items guide). Part I: Cow milk and egg oral immunotherapy: Introduction, methodology, rationale, current state, indications contraindications and oral immunotherapy build-up phase

INTRODUCTION

Cow's milk and egg are the most frequent causes of food allergy in the first years of life. Treatments such as oral immunotherapy (OIT) have been investigated as an alternative to avoidance diets. No clinical practice guides on the management of OIT with milk and egg are currently available.

OBJECTIVES

To develop a clinical guide on OIT based on the available scientific evidence and the opinions of experts.

METHODS

A review was made of studies published in the period between 1984 and June 2016, Doctoral Theses published in Spain, and summaries of communications at congresses (SEAIC, SEICAP, EAACI, AAAAI), with evaluation of the opinion consensus established by a group of experts pertaining to the scientific societies SEICAP and SEAIC.

RESULTS

Recommendations have been established regarding the indications, requirements and practical aspects of the different phases of OIT, as well as special protocols for patients at high risk of suffering adverse reactions.

CONCLUSIONS

A clinical practice guide is presented for the management of OIT with milk and egg, based on the opinion consensus of Spanish experts.

Oral Food Desensitization in Children With IgE-Mediated Cow's Milk Allergy: Immunological Changes Underlying Desensitization

Purpose

This study aimed to evaluate the safety and efficacy to induce clinical desensitization to cow's milk (CM) of an oral immunotherapy (OIT) protocol in a pediatric population with cow's milk allergy (CMA). In addition, the immune responses against β-casein, of peripheral blood mononuclear cells (PBMCs) from CMA patients, before and after the protocol were evaluated and compared to a nonallergic population.

Methods

A group of 20 children with IgE-mediated CMA and 15 nonallergic children were recruited. Allergic subjects underwent an OIT protocol based on weekly doses of commercial semi-skimmed ultra-high temperature treated (UHT) CM, followed by a maintenance phase. Immune profiles and changes in all subjects were investigated by measuring Th1, Th2, and Treg cytokines, transcription factors, and specific IgE and IgG4 levels.

Results

The CM-OIT protocol enabled to desensitize 70% of the allergic patients. Successful OIT was accompanied by significant increases in casein-specific IgG4 levels, together with a reduction in the concentration of antigen-specific IgE and in IL-5, IL-13, and IL-10 production by β-casein-stimulated PBMCs. Baseline significant differences observed between allergic and nonallergic children in IL-13 and IL-5 levels were no longer found once the protocol had finished.

Conclusions

The OIT protocol was safe and effective in inducing milk desensitization in 70% of the children with CMA, leading to alterations in their immune profiles toward a nonallergic phenotype.

Classification of Food Allergens and Cross-Reactivity

Patients with specific food allergies are commonly sensitized to related foods, for example, shrimp with other shellfish and peanut with other legumes. In some instances, this represents a true allergy to the related food, defined as cross-reactivity, while in other instances, it represents a positive skin or IgE test only, in a patient who can eat the related food without difficulty. This is defined as cross-sensitization. It is extremely important that the clinician recognize these patterns of cross-sensitization and cross-reactivity, both to counsel patients on foods that should be avoided and to make sure that foods are not unnecessarily restricted from the diet. In fact, it is very common for patients to be instructed to avoid entire food groups based just on positive tests, which leads to unnecessary dietary restrictions with effects on food choices, nutrition, and quality of life.

Goat's milk allergy without cow's milk allergy: suppression of non-cross-reactive epitopes on caprine β-casein

BACKGROUND AND OBJECTIVE

Goat's milk (GM) allergy associated with tolerance to cow's milk (CM) has been reported in patients without history of CM allergy and in CM-allergic children successfully treated with oral immunotherapy. The IgE antibodies from GM-allergic/CM-tolerant patients recognize caprine β-casein (βcap) without cross-reacting with bovine β-casein (βbov) despite a sequence identity of 91%. In this study, we investigated the non-cross-reactive IgE-binding epitopes of βcap.

METHODS

Recombinant βcap was genetically modified by substituting caprine domains with the bovine counterparts and by performing site-directed mutagenesis. We then evaluated the recognition of modified βcap by IgE antibodies from 11 GM-allergic/CM-tolerant patients and 11 CM-allergic patients or by monoclonal antibodies (mAb) raised against caprine caseins. The allergenic potency of modified βcap was finally assessed by degranulation tests of humanized rat basophil leukaemia (RBL)-SX38 cells.

RESULTS

Non-cross-reactive epitopes of βcap were found in domains 44-88 and 130-178. The substitutions A55T/T63P/L75P and P148H/S152P induced the greatest decrease in IgE reactivity of GM-allergic/CM-tolerant patients towards βcap. The pivotal role of threonine 63 was particularly revealed as its substitution also impaired the recognition of βcap by specific mAb, which could discriminate between βcap and βbov. The modified βcap containing the five substitutions was then unable to trigger the degranulation of RBL-SX38 cells passively sensitized with IgE antibodies from GM-allergic/CM-tolerant patients.

CONCLUSIONS

Although IgE-binding epitopes are spread all over βcap, a non-cross-linking version of βcap was generated with only five amino acid substitutions and could thus provide new insight for the design of hypoallergenic variants.

Recent advances on diagnosis and management of childhood asthma and food allergies

The epidemic of childhood allergic disorders has been associated to the decline of infectious disease. However, exposure to many triggers (airborne viruses, tobacco smoke, pollution, indoor allergens, etc.) contribute to the disease. Breast feeding practices, nutrition, dietary and obesity also play a multifaceted role in shaping the observed worldwide trends of childhood allergies. Guidelines for treatment are available, but their implementation is suboptimal. Then developed countries are slowing learning integrating the development of suitable guidelines with implementation plans. Awareness, psychosocial and family factors strongly influence asthma and food allergy control. Moreover, monitoring tools are necessary to facilitate self-management. By taking into consideration these and many other pragmatic aspects, national public health programs to control the allergic epidemic have been successful in reducing its impact and trace the need for future research in the area.

How to reintroduce cow's milk?

In a child that is allergic to milk, the natural next step, following the elimination diet, is the reintroduction of cow's milk. Several questions may arise. When feasible, this reintroduction has many benefits for the child and his family. However, the disease needs to be well defined by physicians and explained to parents. They need to understand that there are different types of allergy to cow's milk, specifically IgE- and non-IgE-mediated, and each of these may exhibit both a variable duration and frequently an incomplete recovery. Deciding where to first reintroduce cow's milk to a child who has previously followed a milk-free diet, whether it be at home or in a hospital, also frequently presents an issue. Following this first reintroduction, the progressive increase of milk into the diet needs to be managed properly, as not all children will go back to a normal dairy products intake. Recent studies show that most children with milk allergy tolerate products containing baked milk and that their consumption might speed up recovery. Hence, the purpose of the milk challenge in a child on a milk-free diet is becoming, even in a child still reactive to milk, the first step of gradual and individually adapted reintroduction of milk or dairy products. When reintroduction of cow's milk does not work, immunotherapy becomes an option, and this is carried out in specialized centers.

Food allergy and anaphylaxis in pediatrics: update 2010-2012

This review highlights the progress made in food allergy (FA) and anaphylaxis research in pediatrics published in the journal Pediatric Allergy and Immunology since 2010. Putative risk factors for FA are as follows: a family history of allergic disease, particularly in the mother, low birth order, season of birth, and severe atopic eczema. Obstetric practices, antibiotic use, and home environment are factors deserving further research. Diagnostic decision levels and component-specific IgE are useful in the diagnosis of FA; however, oral food challenges remain the gold standard and may also be a means to reduce parental anxiety and to improve education. Oral immunotherapy studies show promise in increasing the threshold of reactivity of allergic patients and therefore improving their quality of life. In single-nut-allergic patients, introduction of other nuts allows broadening the diet and thus reducing the psychological impact of allergen avoidance. Nutritional deficiencies are not uncommon in food-allergic children and should be specifically assessed. The prescription of injectable adrenaline is still insufficient and not consistent among practitioners, requiring improved training and implementation of guidelines. Current research into the epidemiology and immunological mechanisms of FA and tolerance will enable us to devise strategies to both prevent and treat food allergies.