Cow's milk allergy

Autoimmune protocol diet: A personalized elimination diet for patients with autoimmune diseases

The autoimmune protocol diet (AIP) is a personalized elimination diet that aims to determine and exclude the foods that might trigger immune responses, leading to inflammation and symptomatology associated with autoimmune diseases. Focusing on gut health and the importance of the gut microbiome in immune regulation and overall well-being, the AIP starts by eliminating foods that might create negative effects on the patients and continues by developing a personalized and tailored diet plan for them. This comprehensive approach aims to mitigate symptoms and improve quality of life of individuals with autoimmune conditions. This review presents and critically appraises current knowledge on the AIP protocol, highlight any oversights, and discuss findings from relevant clinical trials.

The march from early life food sensitization to allergic disease: a systematic review and meta-analyses of birth cohort studies

BACKGROUND

There is growing evidence for an increase in food allergies. The question of whether early life food sensitization, a primary step in food allergies, leads to other allergic disease is a controversial but important issue. Birth cohorts are an ideal design to answer this question.

OBJECTIVES

We aimed to systematically investigate and meta-analyse the evidence for associations between early food sensitization and allergic disease in birth cohorts.

METHODS

MEDLINE and SCOPUS databases were searched for birth cohorts that have investigated the association between food sensitization in the first 2 years and subsequent wheeze/asthma, eczema and/or allergic rhinitis. We performed meta-analyses using random-effects models to obtain pooled estimates, stratified by age group.

RESULTS

The search yielded fifteen original articles representing thirteen cohorts. Early life food sensitization was associated with an increased risk of infantile eczema, childhood wheeze/asthma, eczema and allergic rhinitis and young adult asthma. Meta-analyses demonstrated that early life food sensitization is related to an increased risk of wheeze/asthma (pooled OR 2.9; 95% CI 2.0-4.0), eczema (pooled OR 2.7; 95% CI 1.7-4.4) and allergic rhinitis (pooled OR 3.1; 95% CI 1.9-4.9) from 4 to 8 years.

CONCLUSION

Food sensitization in the first 2 years of life can identify children at high risk of subsequent allergic disease who may benefit from early life preventive strategies. However, due to potential residual confounding in the majority of studies combined with lack of follow-up into adolescence and adulthood, further research is needed.

Molecular mechanisms of IgE mediated food allergy

The purpose of this review is to collate current knowledge and recent advances in molecular mechanism behind the immediate type hypersensitivity of foods. Food allergy is a growing concern of human health in developed as well as developing countries now days. Food allergic reactions are mostly IgE mediated and also known as immediate type hypersensitivity or type I reaction. This review encompasses a wide range of molecular events during IgE mediated reactions like primary exposure of allergens, processing of allergens by antigen presenting cells, role of transcription factors like GATA-3, STAT-6, NF-AT, c-maf, c-kit and NF-κB, Treg cells, toll like receptors, cytokines and chemokines, class switch to IgE, FcεR1 receptor, priming of IgE on mast cells or basophils, signaling events followed by secondary exposure of allergens, degranulation and release of mediators like leukotrienes, histamines, prostaglandins, β-hexosaminidase and ultimately anaphylaxis. This review may be helpful to beginners as well as experts working in the field of allergy and immunology because of the stepwise explanations of molecular mechanisms involved in IgE mediated reactions.

Application of an acid proteinase from Monascus purpureus to reduce antigenicity of bovine milk whey protein

An acid proteinase from Monascus purpureus No. 3403, MpuAP, was previously purified and some characterized in our laboratory (Agric Biol Chem 48:1637-1639, 1984). However, further information about this enzyme is lacking. In this study, we investigated MpuAP's comprehensive substrate specificity, storage stability, and prospects for reducing antigenicity of whey proteins for application in the food industry. MpuAP hydrolyzed primarily five peptide bonds, Gln(4)-His(5), His(10)-Leu(11), Ala(14)-Leu(15), Gly(23)-Phe(24) and Phe(24)-Phe(25) in the oxidized insulin B-chain. The lyophilized form of the enzyme was well preserved at 30-40°C for 7 days without stabilizers. To investigate the possibility of reducing the antigenicity of the milk whey protein, enzymatic hydrolysates of the whey protein were evaluated by inhibition ELISA. Out of the three main components of whey protein, casein and α-lactalbumin were efficiently degraded by MpuAP. The sequential reaction of MpuAP and trypsin against the whey protein successfully degraded casein, α-lactalbumin and β-lactoglobulin with the highest degree of hydrolysis. As a result, the hydrolysates obtained by using the MpuAP-trypsin combination showed the lowest antigenicity compared with the single application of pepsin, trypsin or pepsin-trypsin combination. Therefore, the overall result suggested that the storage-stable MpuAP and trypsin combination will be a productive approach for making hypoallergic bovine milk whey protein hydrolysates.

Development of two immunoassay formats to detect beta-lactoglobulin: influence of heat treatment on beta-lactoglobulin immunoreactivity and assay applicability in processed food

Milk proteins are commonly used as ingredients in the food industry because of their functional properties, but they can cause severe reactions in milk-allergic individuals. In this work, two enzyme-linked immunosorbent assay (ELISA) formats were developed to detect bovine beta-lactoglobulin. The indirect competitive ELISA involved the use of anti-beta-lactoglobulin antisera, and the sandwich ELISA involved the use of specific antibodies isolated using a beta-lactoglobulin immunosorbent material. The effect of heat treatment on immunoreactivity of the protein in buffer and in milk was determined with both assays. The amount of immunoreactive protein in buffer and in milk decreased as determined by the sandwich ELISA, whereas the amount increased when measuring with the competitive ELISA. Several food products, including meat, bakery products, sauces, and snacks, were analyzed. With both assays, 10 of 11 products in which the ingredient list included the terms "powdered milk" or "milk proteins" contained beta-lactoglobulin. However, the beta-lactoglobulin concentration in these products obtained with the competitive ELISA were much higher than those obtained with the sandwich ELISA. These differences could be explained by the fact that the determination of beta-lactoglobulin concentration by immunoassay is influenced by differences in antibody recognition of the protein present in highly processed foods. Therefore, the antigen-binding properties of antibodies used in a particular immunoassay are important for a correct interpretation of results obtained in food processed at high temperature.

How dietary antigens access the mucosal immune system

The intestinal epithelium is a selective barrier where incompletely-digested food antigens are transmitted to the immune system. Food antigens are often the starting point of intestinal diseases such as food allergy or coeliac disease. The intestinal epithelial cells (IEC) take up and process food antigens mainly by fluid-phase transcytosis involving two functional pathways, one minor direct pathway without degradation and another major lysosomal degradative pathway. Among the peptidic metabolites generated during transepithelial transport of luminal antigens, some have a molecular mass compatible with a binding to restriction (major histocompatibility complex; MHC) molecules; the latter can be up regulated on enterocytes, especially in inflammatory conditions. Indeed, interferon-γ not only increases the paracellular absorption of antigens, but also their transcytosis across epithelial cells. It has been reported that enterocytes may even directly present peptidic epitopes to underlying T-cells. As a new potential way of transmitting peptidic information to the local or systemic immune system, the secretion by IEC of antigen-presenting vesicles called exosomes and bearing MHC–peptide complexes has recently been proposed. Many other factors such as nutritional or environmental factors can also influence the properties of the epithelial barrier and the outcome of the immune response to lumen antigens.

Hypoallergenicity and efficacy of an amino acid-based formula in children with cow's milk and multiple food hypersensitivities

OBJECTIVE

To determine the hypoallergenicity and efficacy of a pediatric amino acid-based formula (AAF), EleCare, for children with cow's milk allergy (CMA) and multiple food allergies (MFA).

STUDY DESIGN

Hypoallergenicity was determined by performing blinded oral food challenges in 31 consecutive children with documented CMA. Growth, tolerance, and biochemical response were evaluated during a nonrandomized feeding study with each child serving as his or her own control.

RESULTS

Thirty-one children (median age, 23.3 months; range, 6 months to 17.5 years) were recruited; 29 had MFA, 17 had acute reactions and cow's milk-specific IgE antibody, and 14 had allergic eosinophilic gastroenteritis. At study entry, 23 were receiving another AAF; 13 had not tolerated extensively hydrolyzed formula. Eighteen subjects with allergic eosinophilic gastroenteritis and/or MFA were followed up while receiving AAF for a median of 21 months (range, 7 to 40 months), with biochemical analysis performed at 4 months. No statistically significant differences were observed in the change in weight or height National Center for Health Statistics z scores from entry; the percent of expected growth exceeded 90%. There was a small decline in percent eosinophils and increase in hemoglobin, hematocrit, and serum ferritin level (P < .05). Except for small increases in plasma leucine and valine levels (P < or = .006), the remaining biochemical markers were unchanged.

CONCLUSIONS

The AAF was hypoallergenic and effective in maintaining normal growth for children with CMA and MFA.

Diagnosis and management of childhood food allergy

The pediatrician plays a pivotal role in the initial diagnosis of food allergy. Alternative diagnoses are considered as a careful history, physical examination, and directed laboratory tests determine the type of adverse reaction and the responsible food. Through elimination diets in infants, appropriately selected tests for specific IgE, and, in some cases, supervised oral food challenges, a diagnosis is secured. Treatment consists of strict dietary elimination with provisions for emergency management of accidental ingestions. Referral to an allergist and dietitian is made as warranted by the severity and type of allergy and for follow-up for possible resolution of the allergy. The pediatrician also provides information to the family for the prevention of allergy in at-risk newborns. Future diagnostic tests and treatment modalities are likely to simplify the management of the food allergic child.

Cow's milk enteropathy: surgical pitfalls

BACKGROUND

Cow's milk-induced intestinal bleeding is a well-recognized cause of rectal bleeding in infancy. The authors report on 5 older children who presented with either visible rectal bleeding or profound anemia associated with occult intestinal bleeding secondary to cow's milk enteropathy.

METHODS

Five children (3 boys and 2 girls) aged between 20 months and 9 years were referred for further investigation of gastrointestinal bleeding. Two had been investigated previously on multiple occasions, and both had undergone laparotomies with negative results. Further investigations showed evidence of allergic colitis in 3 detected only on proximal colonic biopsy findings.

RESULTS

In all cases, bleeding resolved completely after instituting a cow's milk-free diet. Two of the patients subsequently have undergone a cow's milk challenge leading to prompt recurrence of symptoms, which again resolved after simple dietary manipulation.

CONCLUSIONS

Cow's milk enteropathy may cause overt rectal bleeding or profound anemia from occult intestinal bleeding even in older children. Histological abnormalities in such cases may be confined to the proximal colon. After appropriate investigation, a trial of cow's milk exclusion should always be considered before laparotomy for obscure, chronic gastrointestinal bleeding in children.

Cross-reactivity between milk proteins from different animal species

BACKGROUND

Cow's milk allergy is quite frequent in the first years of human life. When breast-feeding is not possible, a cow's milk substitute must be provided for allergic subjects. Different alternatives to cow's milk have been suggested as protein sources (soy, hydrolysed proteins, goat's milk, etc.), but all these dietetic solutions are not without risks for polyallergic or more sensitive subjects.

OBJECTIVE

To obtain new information on the suitability of other mammalian milks for allergic children, we evaluated the cross-reactivity between milk proteins from different animal species.

METHODS

Milk samples were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). To detect antibody-antigen complexes, immunoblotting was performed by using sera from children allergic to cow's and ewe's milk (RAST class >/= 4) and monoclonal antibodies (MoAb) specific for bovine proteins (caseins and beta-lactoglobulin).

RESULTS

IgEs from children allergic to cow's milk are capable of recognizing most part of milk proteins from mammals bred in European countries (ewe, goat, buffalo), while no serum used in this study contains IgEs reacting with camel's milk proteins. Camel's milk was also not recognized from circulating IgEs from a child specifically allergic to ewe's milk. Specific antibovine monoclonal antibodies cross-reacted with proteins from other mammalian species, apart from those of camel.

CONCLUSIONS

Homologies in amino acidic composition could justify the cross-reactivity observed between proteins from different animal species. On the other hand, the phylogenetic difference could be responsible for the failed recognition of camel's proteins by circulating IgEs and monoclonal antibodies.

A murine model of IgE-mediated cow's milk hypersensitivity

BACKGROUND

Cow's milk allergy (CMA) is one of the leading causes of food allergy in children. Understanding the mechanisms involved in the development of CMA has been hampered by the lack of suitable animal models.

OBJECTIVE

We sought to develop a mouse model of IgE-mediated cow's milk hypersensitivity (CMH) that mimics the clinical features of immediate CMA in humans.

METHODS

Three-week-old C3H/HeJ mice were sensitized by intragastric administration of cow's milk (CM) plus cholera toxin and boosted 5 times at weekly intervals.

RESULTS

CM-specific IgE antibody levels were significantly increased at 3 weeks and peaked at 6 weeks after the initial feeding. Intragastric challenge with CM at week 6 elicited systemic anaphylaxis accompanied by vascular leakage, significantly increased plasma histamine, and increased intestinal permeability to casein. Histologic examination of intestinal tissue revealed marked vascular congestion, edema, and sloughing of enterocytes. The role of IgE in mediating CMH was confirmed by abrogation of passive cutaneous anaphylaxis reactions by heat inactivation of immune sera. Development of IgE-mediated CMH in this model is likely to be TH2 cell mediated because in vitro stimulation of spleen cells from mice allergic to CM induced significant increases in the levels of IL-4 and IL-5, but not IFN-gamma.

CONCLUSION

This model should provide a useful tool for evaluating the immunopathogenic mechanisms involved in CMA and for exploring new therapeutic approaches.