Allergenicity evaluation of fermented milk prepared by co-fermentation of Lactobacillus plantarum 7-2 and commercial starters after in vitro digestive

Milk allergy is one of the most common food allergies, in which αS-casein is the major milk allergen. Under optimized conditions, mixed starter (containing Lactobacillus plantarum 7-2 and commercial starter) effectively degraded αS-casein of skimmed milk and reduced the pressure of stomach digestion. The fermented milk prepared by mixed starter was determined by ELISA, the antigenicity of αS-casein was reduced by 77.53%. Compared with the fermented milk prepared by commercial starter, label-free quantitative proteomics demonstrated that the mixed starter more efficiently degraded the epitopes of major milk allergens and influenced the digestion pattern of the fermented milk. Therefore, L. plantarum 7-2 shows positive potential in reducing the antigenicity of αS-casein and others. In addition, this study predicted that the new epitopes produced in the fermentation process could induce immunity using molecular simulation.

Oral Immunotherapy in Food Allergy: A Critical Pediatric Perspective

There is evidence that in children with persistent IgE-mediated food allergy (FA) to cow's milk, hen's egg, and peanut, oral allergen-specific immunotherapy (OIT) may increase the reaction threshold to the culprit food allergen(s). OIT may protect patients from the occurrence of severe reactions in case of accidental ingestion of the culprit food during treatment. Notwithstanding, many gaps are still unsolved, including safety issues, identification of predictive biomarkers, and post-desensitization efficacy. In this perspective, the use of omalizumab (Anti-IgE monoclonal antibody) has been proposed as an adjunctive treatment to OIT in order to reduce the risk of allergic reactions related to OIT. This review aims to summarize the current evidence and unmet needs on OIT in children with FA to enhance the development of longitudinal, prospective, and well-designed studies able to fill the current gaps soon.

Evaluation of oral immunotherapy efficacy and safety by maintenance dose dependency: A multicenter randomized study

Background

Generally, oral immunotherapy (OIT) aims for daily administration. Recently, the efficacy of treatment with OIT at a low dose has been reported. However, the optimal dose and the evaluation of dose-dependent OIT outcome have not been described.

Methods

A multicenter, parallel, open-labeled, prospective, non-placebo controlled, randomized study enrolled 101 Japanese patients for treatment with OIT. We hypothesized that target dose OIT would induce short-term unresponsiveness (StU) earlier than reduced dose OIT. StU was defined as no response to 6200 mg whole egg, 3400 mg milk, and 2600 mg wheat protein, as evaluated by oral food challenge after 2-week ingestion cessation. To compare the two doses of OIT efficacy, the maximum ingestion doses during the maintenance phase of OIT were divided into 100%-dose or 25%-dose groups against their target StU dose, respectively. A total of 51 patients were assigned to the 100%-dose group [hen's egg (HE) = 26, cow's milk (CM) = 13, wheat = 12] and 50 to the 25%-dose group (HE = 25, CM = 13, wheat = 12). Primary outcome was established by comparing StU at 1 year. Secondary outcome was StU at 2 years and established by comparing allergic symptoms and immunological changes.

Results

The year 1 StU rates (%) for the 100%- and 25%-dose groups were 26.9 vs. 20.0 (HE), 7.7 vs. 15.4 (CM), and 50.0 vs. 16.7 (wheat), respectively. The year 2 StU rates were 30.8 vs. 36.0 (HE), 7.7 vs. 23.1 (CM), and 58.3 vs. 58.3 (wheat), respectively. There were no statistically significant differences in StU between years 1 and 2. The total allergic symptom rate in the 25%-dose group was lower than that in the 100%-dose group for egg, milk, and wheat. Antigen-specific IgE levels for egg-white, milk, and wheat decreased at 12 months.

Conclusions

Reduced maintenance dose of egg OIT showed similar therapeutic efficacy to the target dose. However, we were not able to clearly demonstrate the efficacy, particularly for milk and wheat. Reducing the maintenance dose for eggs, milk, and wheat may effectively lower the symptoms associated with their consumption compared to the target OIT dose. Furthermore, aggressive reduction of the maintenance dose might be important for milk and wheat, compared to the 25%-dose OIT.

Trial registration

UMIN000009373, Multicenter Oral Immunotherapy for Hen's Egg, Cow's Milk, and Wheat-Allergic Children at Outpatient Clinic.

Allergen-Specific Immunotherapy for Immunoglobulin E-Mediated Food Allergy

Food allergy is a potentially life-threatening condition and a significant public health concern worldwide. The current management includes food avoidance and use of emergency medications. The growing prevalence of food allergy drives research towards specific allergen immunotherapy (AIT), which represents a potential disease-modifying approach. AIT consists of the progressive administration of amounts of the offending allergen in order to induce food desensitisation, creating an increase in reaction threshold with regular exposure to the allergen. AIT can be performed through oral, sublingual, epicutaneous, and subcutaneous routes. The target is to achieve post desensitisation effectiveness: a long-lasting condition allowing patients to introduce food without reactions, even after a period of discontinuation of the offending food.

Long-term clinical and immunological effects of probiotic and peanut oral immunotherapy after treatment cessation: 4-year follow-up of a randomised, double-blind, placebo-controlled trial

BACKGROUND

Oral immunotherapy has attracted much interest as a potential treatment for food allergy, yet little is known about its long-term effects. We aimed to assess long-term outcomes in participants who completed a randomised, double-blind, placebo-controlled trial of combined probiotic and peanut oral immunotherapy (PPOIT), which was previously shown to induce desensitisation and 2-week sustained unresponsiveness.

METHODS

All participants who completed the PPOIT randomised trial were eligible to participate in this follow-up study 4 years after treatment cessation. Peanut intake and adverse reactions to peanut in the 4 years after treatment cessation were systematically documented with a structured questionnaire administered by allergy nurses. Additionally, participants were invited to undergo peanut skin prick tests, measurement of peanut sIgE and sIgG4 concentrations, and double-blind placebo-controlled peanut challenge to assess 8-week sustained unresponsiveness.

FINDINGS

48 (86%) of 56 eligible participants were enrolled in the follow-up study. Mean time since stopping treatment was 4·2 years in both PPOIT (SD 0·6) and placebo (SD 0·7) participants. Participants from the PPOIT group were significantly more likely than those from the placebo group to have continued eating peanut (16 [67%] of 24 vs one [4%] of 24; absolute difference 63% [95% CI 42-83], p=0·001; number needed to treat 1·6 [95% CI 1·2-2·4]). Four PPOIT-treated participants and six placebo participants reported allergic reactions to peanut after intentional or accidental intake since stopping treatment, but none had anaphylaxis. PPOIT-treated participants had smaller wheals in peanut skin prick test (mean 8·1 mm [SD 7·7] vs 13·3 mm [7·6]; absolute difference -5·2 mm [95% CI -10·3 to 0·0]; age-adjusted and sex-adjusted p=0·035) and significantly higher peanut sIgG4:sIgE ratios than placebo participants (geometric mean 67·3 [95% CI 10·3-440·0] vs 5·2 [1·2-21·8]; p=0·031). Seven (58%) of 12 participants from the PPOIT group attained 8-week sustained unresponsiveness, compared with one (7%) of 15 participants from the placebo group (absolute difference 52% [95% CI 21-82), p=0·012; number needed to treat 1·9 [95% CI 1·2-4·8]).

INTERPRETATION

PPOIT provides long-lasting clinical benefit and persistent suppression of the allergic immune response to peanut.

FUNDING

Murdoch Childrens Research Institute and Australian Food Allergy Foundation.

Allergen-Specific Immunotherapy

Allergen-specific immunotherapy remains the only causal treatment of allergic disease to date. Its efficacy in symptom reduction was demonstrated in double blind, placebo-controlled studies of allergic rhinoconjunctivitis, allergic asthma, and Hymenoptera venom hypersensitivity, including long-term effects after discontinuation of treatment. In addition, immunotherapy decreases the risk of developing new sensitisations to aeroallergens in monosensitised patients and allergic asthma in patients with mere allergic rhinitis. The mechanism of immunotherapy entails redirection of the T lymphocyte response from a T helper cell Type 2 phenotype in favour of induction of regulatory T cells and/or immune deviation toward a T helper cell Type 1 phenotype, with resulting inhibition of downstream effector pathways and induction of immunoglobulin G-associated blocking antibodies. Two main application forms are used in clinical practice: subcutaneous immunotherapy and sublingual immunotherapy. The advantage of subcutaneous immunotherapy is its proven efficacy over a broad range of indications. Disadvantages are systemic allergic reactions and inconvenience for the patient due to frequent doctor visits. Sublingual immunotherapy has been shown to result in less systemic allergic reactions and may be more convenient due to home application; however, efficacy has only been proven for allergic rhinitis. For clinicians, the adherence to practice guidelines and thorough knowledge of allergen products, application routes, indications, immunomodulatory mechanisms, efficacy, safety, and cost-effectiveness is important for successful treatment and will be addressed in this review article.

Primary eosinophilic gastrointestinal disorders in children who have received food oral immunotherapy

BACKGROUND

Food oral immunotherapy (OIT) involves the administration of the food allergen causing the symptoms, in order to induce tolerance. Primary eosinophilic gastrointestinal disorders (PEGDs) are characterised by an eosinophil-rich inflammation affecting different locations of the digestive tract. We present a series of patients with PEGDs in a group of children following OIT with milk and/or egg.

MATERIAL AND METHODS

A prospective study during the period 2006-2014 was performed in paediatric patients subjected to OIT with milk and/or egg. When these children present persistent gastrointestinal symptoms, they are referred to the Paediatric Gastroenterology Unit for evaluation.

RESULTS

Primary eosinophilic gastrointestinal disorders were diagnosed in eight of the 128 cases of OIT (6.25%). The time to PEGDs development was variable: two cases showed symptoms during OIT, and the rest with a median time of 29 months (15-48 months). Food treatment discontinuation was not required in four of the five cases of eosinophilic oesophagitis, although food removal was necessary in patients with eosinophilic gastroenteritis.

CONCLUSIONS

We report the highest prevalence of PEGDs in children subjected to OIT, and the first cases of eosinophilic gastroenteritis following food OIT. The monitoring of new digestive signs and symptoms after OIT is crucial for the diagnosis of these disorders, and prolonged follow-up is required. The management of such patients and the need or not to eliminate the food should be assessed on an individualised basis, according to the severity of the condition, its evolution and response to different treatment alternatives.

New approach for food allergy management using low-dose oral food challenges and low-dose oral immunotherapies

A number of studies have suggested that a large subset of children (approximately 70%) who react to unheated milk or egg can tolerate extensively heated forms of these foods. A diet that includes baked milk or egg is well tolerated and appears to accelerate the development of regular milk or egg tolerance when compared with strict avoidance. However, the indications for an oral food challenge (OFC) using baked products are limited for patients with high specific IgE values or large skin prick test diameters. Oral immunotherapies (OITs) are becoming increasingly popular for the management of food allergies. However, the reported efficacy of OIT is not satisfactory, given the high frequency of symptoms and requirement for long-term therapy. With food allergies, removing the need to eliminate a food that could be consumed in low doses could significantly improve quality of life. This review discusses the importance of an OFC and OIT that use low doses of causative foods as the target volumes. Utilizing an OFC or OIT with a low dose as the target volume could be a novel approach for accelerating the tolerance to causative foods.

Children who were treated with oral immunotherapy for cows' milk allergy showed long-term desensitisation seven years later

AIM

This was a follow-up of 28 schoolchildren with cows' milk allergy (CMA) who attended a randomised double-blind placebo-controlled oral immunotherapy (OIT) study. In the original study, 26 (92.9%) completed the six-month escalation phase, and 25 (89.3%) used milk daily at 12 months and 24 (85.7%) at 36 months. This study evaluated the outcome seven years later, with special attention paid to milk consumption and symptoms.

METHODS

Outcome data were collected through a postal questionnaire completed three, four and five years after enrolment and by a phone questionnaire after seven years. We asked about the daily dose of milk products, any adverse reactions, any medication needed and possible discontinuation of daily milk consumption.

RESULTS

Data were available at the seven-year point for 24 children and 14 (58.3%) of these continued to use milk (≥200 mL) or milk products (protein ≥6400 mg) daily for seven years. However, three (21.4%) of these still reported symptoms associated with milk consumption. Of the 10 remaining children, two children used milk products daily but consumed less due to symptoms and eight (33.3%) had discontinued milk consumption.

CONCLUSION

Oral immunotherapy was an effective and safe way of desensitising schoolchildren with persistent CMA.

Position document: IgE-mediated cow's milk allergy

The present document offers an update on the recommendations for managing patients with cow's milk allergy - a disorder that manifests in the first year of life, with an estimated prevalence of 1.6-3% in this paediatric age group. The main causal allergens are the caseins and proteins in lactoserum (beta-lactoglobulin, alpha-lactoalbumin), and the clinical manifestations are highly variable in terms of their presentation and severity. Most allergic reactions affect the skin, followed by the gastrointestinal and respiratory systems, and severe anaphylaxis may occur. The diagnosis of cow's milk allergy is based on the existence of a suggestive clinical history, a positive allergy study and the subsequent application of controlled exposure testing, which constitutes the gold standard for confirming the diagnosis. The most efficient treatment for cow's milk allergy is an elimination diet and the use of adequate substitution formulas. The elimination diet must include milk from other mammals (e.g., sheep, goat, etc.) due to the risk of cross-reactivity with the proteins of cow's milk. Most infants with IgE-mediated cow's milk allergy become tolerant in the first few years of life. In those cases where cow's milk allergy persists, novel treatment options may include oral immunotherapy, although most authors do not currently recommend this technique in routine clinical practice. Enough evidence is not there to confirm the efficacy of elimination diets in the mother and infant for preventing the appearance of cow's milk allergy. Likewise, no benefits have been observed with prebiotic and probiotic dietetic supplements in infants for preventing food allergy.

Immunotherapy with B cell epitopes ameliorates inflammatory responses in Balb/c mice

Osmotin, a protein from the pathogenesis-related family (PR-5), has been identified as an allergen based on in-silico and in-vitro studies. In the present study, three B cell epitopes of osmotin with single and double amino acid modifications were studied for immunotherapy in a murine model. The single-modification peptides (P-1-1, P-2-1 and P-3-1) and double-modification peptides (P-1-2, P-2-2 and P-3-2) showed significantly lower immunoglobulin (Ig)E binding with patients' sera compared to osmotin (P < 0·01). These peptides showed reduced IgE binding compared to the unmodified peptides (B cell epitopes) P-1, P-2 and P-3. Among the modified peptides, P-2-1, P-3-1, P-2-2 and P-3-2 showed significant reduction in IgE binding and were used for immunotherapy in mice. The sera of mice group treated with peptides showed a significant increase in IgG2a level and a significant decrease in IgE and IgG1 levels (P < 0·05). The mice that received peptide immunotherapy showed a shift from a T helper type 2 (Th2) to Th1 type where interferon (IFN)-γ and interleukin (IL)-10 levels were elevated, with a significant increase in groups treated with peptides P-3-1 and P-3-2 (P < 0·05). There was a reduction in the IL-4 and IL-5 levels in bronchoalveolar lavage fluid (BALF) in the peptide-treated mice groups. Total cell count and eosinophil count in BALF of the peptide-treated groups was also reduced compared to the phosphate-buffered saline (PBS)-treated group. Lung histology showed a significant reduction in cellular infiltrate in mice treated with P-2-2 and P-3-2 compared to PBS. In conclusion, peptides P-2-2 and P-3-2 lowered inflammatory responses and induced a Th1 response in mice.