Rapid diagnosis of egg allergy by targeting ovalbumin specific IgE and IgG4 in serum at a disposable electrochemical immunoplatform

This work reports the first electrochemical bioplatforms described to date for the single and simultaneous determination of two immunoglobulin (Igs) subtypes, IgE and IgG4, considered as reliable markers for the...

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.

Integrative Transcriptomics Reveals Activation of Innate Immune Responses and Inhibition of Inflammation During Oral Immunotherapy for Egg Allergy in Children

We previously reported the results of a randomized, open-label trial of egg oral immunotherapy (OIT) in 50 children where 44% were desensitized and 46% were partially desensitized after 8 months of treatment. Here we focus on cell-mediated molecular mechanisms driving desensitization during egg OIT. We sought to determine whether changes in genome-wide gene expression in blood cells during egg OIT correlate with humoral responses and the clinical outcome. The blood cell transcriptome of 50 children receiving egg OIT was profiled using peripheral blood mononuclear cell (PBMC) samples obtained at baseline and after 3 and 8 months of OIT. We identified 467 differentially expressed genes (DEGs) after 3 or 8 months of egg OIT. At 8 months, 86% of the DEGs were downregulated and played a role in the signaling of TREM1, IL-6, and IL-17. In correlation analyses, Gal d 1–4-specific IgG4 antibodies associated positively with DEGs playing a role in pathogen recognition and antigen presentation and negatively with DEGs playing a role in the signaling of IL-10, IL-6, and IL-17. Desensitized and partially desensitized patients had differences in their antibody responses, and although most of the transcriptomic changes were shared, both groups had also specific patterns, which suggest slower changes in partially desensitized and activation of NK cells in the desensitized group. OIT for egg allergy in children inhibits inflammation and activates innate immune responses regardless of the clinical outcome at 8 months. Changes in gene expression patterns first appear as posttranslational protein modifications, followed by more sustained epigenetic gene regulatory functions related to successful desensitization.

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 explored the ability of proteomic methods to identify minute amounts of milk/egg allergens in a brand of PAL-labelled milk- and egg-free biscuits. We evaluated the reactivity of children with severe milk and egg allergy, by oral food challenge. 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 at immunoblotting. None of the patients reacted to biscuits. Egg and milk proteins were found under the 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. Our biscuits did not contain allergens of clinical significance. Their milk/egg content 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 allergenic foods and can be used to avoid unnecessary PAL.

Efficacy and safety of allergen immunotherapy for IgE-mediated food allergy: systematic review and meta-analysis

Background There is substantial interest in allergen-specific immunotherapy in food allergy. We systematically reviewed its efficacy and safety. Methods We searched six bibliographic databases from 1946 to 30 April 2021 for randomised controlled trials about immunotherapy alone or with biologicals in IgE-mediated food allergy confirmed by oral food challenge. We pooled the data using random-effects meta-analysis. Results We included 36 trials with 2,126 participants, mainly children. Oral immunotherapy increased tolerance whilst on therapy for peanut (RR 9.9, 95% CI 4.5. to 21.4, high certainty); cow’s milk (RR 5.7, 1.9 to 16.7, moderate certainty) and hen’s egg allergy (RR 8.9, 4.4 to 18, moderate certainty). The number needed to treat to increase tolerance to a single dose of 300mg or 1000mg peanut protein was 2. In peanut allergy, oral immunotherapy did not increase adverse reactions (RR 1.1, 1.0 to 1.2, low certainty) or severe reactions (RR 1,6, 0.7 to 3.5, low certainty). It may increase adverse reactions in cow’s milk (RR 3.9, 2.1 to 7.5, low certainty) and hen’s egg allergy (RR 7.0, 2.4 to 19.8, moderate certainty), but reactions tended to be mild and gastrointestinal. Epicutaneous immunotherapy increased tolerance whilst on therapy for peanut (RR 2.6, 1.8 to 3.8, moderate certainty). Results were unclear for other allergies and administration routes. Conclusions Oral immunotherapy improves tolerance whilst on therapy and is probably safe in peanut, cow’s milk and hen’s egg allergy. However, our review found little about whether this improves quality of life, is sustained or cost-effective.