Severe food allergies: can they be considered rare diseases?

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.

Food labeling issues for severe food allergic patients

Food allergy carries high importance and responsibility, affecting an estimated 220 million people worldwide. It is a frequent cause of food-induced anaphylaxis, a life-threatening condition requiring a toll of about one death per 50 million people a year worldwide. In order to help patients to identify allergenic foods and thus avoid anaphylactic reactions, 66 countries over the 5 continents require by law that allergenic ingredients must be declared when used in prepackaged foods. Unfortunately, the mandatory allergen list is not uniform, but varies among different countries. The widespread adoption of Precautionary Allergen Labeling (PAL) results in a proliferation of unregulated PALs with different informative statements. In this situation, the need of a scientific consensus on the definition of food allergy and the identification of a tolerable risk with routinely used detection assays, considering not only the eliciting dose but also the food source, is urgent. The aim of this manuscript is: 1) to draw a picture of the global situation in terms of PALs, and 2) to highlight new approaches that could aid in tackling the problem of regulating the labeling of allergens. These include the Voluntary Incidental Trace Allergen Labelling (VITAL) system, which intersects reference doses and labelling decisions, and a direct quantification of trace amounts of allergens at lower limit of detection (LOD) levels in the food itself through proteomics. We here highlight how, although with some limitations, the steady advances in proteomic approaches possess higher sensitivity than the recommended VITAL reference doses, allowing the identification of allergens at much lower LOD levels than VITAL. Considering that each assay used to detect allergen in food products carries method-specific issues, a more comprehensive and harmonized approach implementing both quantitative and qualitative methods could help overcoming the risk stratification approach and the overuse of PALs, offering promise as the field moves forward towards improving consumers' quality of life.

Consensus on DEfinition of Food Allergy SEverity (DEFASE) an integrated mixed methods systematic review

BACKGROUND AND AIMS

The term "Food Allergy" refers to a complex global health problem with a wide spectrum of severity. However, a uniform definition of severe food allergy is currently missing. This systematic review is the preliminary step towards a state-of-the-art synopsis of the current evidence relating to the severity of IgE-mediated food allergy; it will inform attempts to develop a consensus to define food allergy severity by clinicians and other stakeholders.

METHODS

We undertook a mixed-methods systematic review, which involved searching 11 international biomedical databases for published studies from inception to 31 December 2019. Studies were independently screened against pre-defined eligibility criteria and critically appraised by established instruments. The substantial heterogeneity of included studies precluded meta-analyses and, therefore, narrative synthesis of quantitative and qualitative data was performed.

RESULTS

We found 23 studies providing eligible primary data on symptom-specific severity of food allergic reactions, and 31 previously published symptom-severity scoring systems referred to food allergic reactions. There were seven studies which assessed quality-of-life measures in patients (and family members) with different food allergy severity and two studies that investigated the economic burden of food allergy severity. Overall, the quality and the global rating of all included studies were judged as being moderate.

CONCLUSIONS

There is heterogeneity among severity scoring systems used and even outcomes considered in the context of severity of food allergy. No score has been validated. Our results will be used to inform the development of an international consensus to define the severity of food allergy.

SYSTEMATIC REVIEW REGISTRATION

A protocol was prospectively registered with the International Prospective Register of Systematic Reviews (PROSPERO) database with the registration number CRD42020183103 (https://www.crd.york.ac.uk/prospero/#recordDetails).

Consensus on DEfinition of Food Allergy SEverity (DEFASE): Protocol for a systematic review

Background and aims

The term “Food Allergy” refers to a complex global health problem with a wide spectrum of severity. However, a uniform definition of severe food allergy is currently missing. This systematic review is the preliminary step towards a state-of-the-art synopsis of the current evidence relating to the severity of IgE-mediated food allergy; it will inform attempts to develop a consensus to define food allergy severity by clinicians and other stakeholders.

Methods

We will undertake a systematic review, which will involve searching international biomedical databases for published studies. Studies will be independently screened against pre-defined eligibility criteria and critically appraised by established instruments. Data will be descriptively and, if possible and applicable, quantitatively synthesised.

Ethics and dissemination

This study does not require any specific ethical approval since it is a systematic review. We plan to report results from this systematic review in a peer reviewed journal. These results will be used to inform the development of an international consensus to define severe food allergy. Author's potential conflicts of interest are clearly stated.

PROSPERO registration number

CRD42020183103.

Oral immunotherapy for peanut allergy: The con argument

Background

In some countries of the world, peanut allergy represents an important source of anaphylactic reactions. Traditionally treated with the avoidance of responsible allergens, this condition can also be targeted by oral peanut immunotherapy.

Methods

In this study, we review the beneficial and side effects of currently available forms of peanut oral immunotherapy (POIT). We report the discussions resulting from the publication of a meta-analysis that brought to light the downsides of oral immunotherapy for peanuts.

Results

In some clinical situations, the risk-benefit ratio can favor peanut oral immunotherapy over avoidance. In many other situations, this is not the case. The decision must be based on the values and preferences of clinicians and patients. Those not ready to accept serious adverse effects from POIT are likely to continue the elimination diet; those motivated to achieving desensitization, and prepared to accept serious adverse effects, may choose to undergo POIT.

Conclusions

Without being prejudiced against peanut oral immunotherapy, we indicate the possible evolution of treatment for this condition is in a rapidly evolving broader scenario. Among the future options, sublingual immunotherapy, parenteral immunotherapy with modified allergens, transcutaneous immunotherapy, and the use of biologics will become important options.

A well-tolerated new amino acid-based formula for cow's milk allergy

Objectives

Infants with cow's milk allergy (CMA) are in need of a substitute formula up to 2 years. The are three requisites for a substitute of milk in CMA: tolerability, nutritional adequacy, and cost‐effectiveness. We evaluate here the tolerability of a new amino acid–based infant formula for the management of CMA.

Methods

In a phase III/IV prospective, multicentre, open‐label, international study, infants and children with immunoglobulin E‐mediated CMA were exposed to a diagnostic double‐blinded, placebo‐controlled food challenge with a new amino acid formula by Blemil Plus Elemental using Neocate as the placebo. If tolerant to it, the study formula was integrated into the patients’ usual daily diet for 7 days. Efficacy on day 7 was assessed in terms of symptoms associated with CMA, amount of formula consumed, nutritional and energy intake, and anthropometric data.

Results

Thirty children (17 M and 13 F; median age, 1.58; range, 0.08‐12.83 years) completed the open challenge and were able to consume the study formula for at least 7 days. No signs or symptoms of allergic reactions were recorded among children assuming either the test or the control formula, with a lower 95% one‐sided confidence interval for the proportion of subjects who did not experience allergic reactions above 90%. Sixteen patient under the age of two continued with the optional extension phase.

Conclusions

The study formula meets the American Academy of Pediatric criteria for hypoallergenicity and is well tolerated in short‐term use. During optional phase, growth of the patients was not hindered by the study formula.

Impact of Omalizumab on Food Allergy in Patients Treated for Asthma: A Real-Life Study

BACKGROUND

The effects of omalizumab on food allergy thresholds have been little studied.

OBJECTIVE

To assess the real-life effects of omalizumab on food threshold tolerability in children treated for severe asthma.

METHODS

In this observational, real-life, efficacy study, we reviewed the food allergen thresholds of patients with severe asthma, as well as their immediate reactions to 2+ foods before and after a 4-month treatment with omalizumab. We also evaluated their control of asthma and their quality of life, as measured by Pediatric Quality of Life Inventory (PedsQL).

RESULTS

Fifteen children, allergic to 37 foods, were evaluated. Omalizumab induced an increase in the allergen threshold for milk, egg, wheat, and hazelnut from a mean 1012.6 ± 1464.5 mg protein to 8727 ± 6463.3 eliciting dose (P < .001). A total of 70.4% of subjects tolerated the complete challenge dose after 4 months of treatment with omalizumab. These foods were reintroduced in the patients' diet without the need for any oral immunotherapy procedures. The remaining foods were partially tolerated. The number of reactions to the unintended ingestion of allergenic foods over 4 months dropped from 47 to 2. The PedsQL increased from 61 ± 5.32 to 87 ± 7.33 (parental judgment; P < .001) and from 65 ± 7.39 to 90 ± 4.54 (patients' judgment; P < .001). The mean cost of omalizumab was €1311.63 per month.

CONCLUSIONS

During treatment with omalizumab for severe uncontrolled asthma, the food allergen threshold increases to 8.6 times its original value. The quality of life of patients also increased, due to a better asthma control and a reduction in dietary restrictions. The cost/benefit ratio of such treatment for selected cases of food allergy remains to be evaluated.