Role of serum-specific immunoglobulin E in egg allergy: a comprehensive study of Portuguese pediatric patients.

INTRODUCTION: Food allergies represent a growing public health concern, particularly among children. This study aims to examine egg allergy in pediatric patients and analyze the value of serum-specific immunoglobulin E (sIgE) levels as predictive biomarkers for oral food challenge (OFC) outcomes. METHODS: Retrospective study, involving pediatric patients with suspected IgE-mediated egg allergy, conducted at a tertiary hospital. RESULTS: Data from 176 pediatric patients were analyzed, revealing a higher male prevalence (59.1%). Most cases (40.3%) presented symptoms in the first year of life, predominantly mucocutaneous symptoms (46%). OFC results varied across various forms of egg presentation, with cooked egg being the most frequently tested food. Positive OFCs were observed in 14.6% (n = 36) of cases. The study identified specific egg protein biomarkers for positive OFC, with ovalbumin for raw egg (sIgE > 1.28 KUA/L; area under the curve [AUC] = 0.917; sensitivity [S] 100%; and specificity [Sp] 92%), ovomucoid for cooked egg (sIgE > 0.99 KUA/L; AUC = 0.788, 95%; S: 79%; and Sp: 74%), and ovomucoid for baked egg (sIgE> 4.63 KUA/L; AUC = 0.870; S: 80%; and Sp: 85%) showing predictive capacities. CONCLUSIONS: The findings underscore the importance of considering various forms of egg presentation in the diagnosis and management of egg allergy. The findings highlight the valuable discriminatory capacity and provided reliable biomarkers, such as ovalbumin for raw egg and ovomucoid for cooked and baked egg in risk assessment, aiding in predicting OFC outcomes and helping clinicians to make informed decisions in diagnosing and managing egg allergies, thus improving patient care and quality of life.

Food Matrix Composition Affects the Allergenicity of Baked Egg Products.

BACKGROUND: Egg allergy is common and caused by sensitization to ovomucoid and/or ovalbumin. Many egg-allergic patients are able to tolerate eggs baked into other foods, such as muffins. Although heating egg extensively reduces allergens, the effect of other food ingredients on allergenicity of eggs, or the "matrix effect," is less well studied. OBJECTIVE: We aimed to define how food matrices impact the matrix effect in egg allergenicity. METHODS: Enzyme-linked immunosorbent assay was used to quantify ovalbumin and ovomucoid in extracts from various baked egg products: plain baked egg without a matrix, and muffins baked using either wheat flour, rice flour, or a wheat flour/banana puree mix. Allergen-specific immunoglobulin E (IgE)-blocking enzyme-linked immunosorbent assays were performed using the egg product extracts on egg-allergic patient sera to determine whether the amount of extracted egg protein in each extract correlated with how well the extracts could bind patients' egg IgE. RESULTS: Baking eggs in any muffin matrix led to an increase in the amount of extractable ovalbumin and a decrease in the amount of extractable ovomucoid compared with plain baked egg. Compared with wheat muffins, rice muffins had more extractable ovalbumin and wheat/banana muffins had more extractable ovalbumin and ovomucoid. The egg allergens in the extracts were able to block egg-allergic patients' egg IgE. CONCLUSIONS: Food matrices affect egg allergen availability. Patients and families should be advised that substitutions in baked egg muffin recipes can affect the amount of egg allergens in foods and potentially affect the risk of food allergic reaction.

Pediatric oral food challenges in the outpatient setting: A single-center experience.

Background: Oral food challenge (OFC) is the criterion standard for diagnosing food allergy (FA). It is important to have parameters to aid in selecting ideal OFC candidates. Objective: We sought to characterize outcomes and predictors of OFCs for common food allergens. Methods: We completed a retrospective chart review of all OFCs for IgE-mediated FA performed at Duke University pediatric allergy clinics from June 2017 through May 2022. Patients were deemed eligible for milk, egg, and nut OFC if testing revealed a specific IgE level not exceeding 2 kU/L and a skin prick test (SPT) resulting in a wheal size not exceeding 5 mm. Different parameters were followed for selecting candidates for baked challenge. Results: A total of 663 OFCs were conducted on 510 patients (59% male). The most common foods challenged were peanut (26%), plain egg (23%), baked egg (8%), and milk (8%), with pass rates of 84%, 88%, 62%, and 84%, respectively. Of the patients who failed OFC, 84% had objective symptoms, 23% had multisystemic reactions, and 15% required epinephrine. Although the presence of a personal or family history of atopy or prior failed OFC was not associated with outcomes, a history of anaphylaxis (regardless of the trigger) was associated with increased risk of failure. Conclusion: Although there are no established consensus guidelines, our study provides a benchmark illustrating that cutoffs of a specific IgE level not exceeding 2 kU/L and SPT finding not exceeding 5 mm result in a failure rate of approximately 13% for nonbaked milk, nonbaked egg, and nuts. The high rate of failed baked egg OFCs is likely related to selection bias, but our results illustrate the low negative predictive value of ovomucoid.

Egg allergy and yellow fever vaccination.

OBJECTIVE: Evaluate biomarkers capable of safely guiding Yellow fever vaccine (YFV) vaccination among individuals suspicious of hen's egg allergy, and identify factors associated with a higher risk for adverse events after immunization (AEAI). METHODS: Patients underwent skin prick test (SPT) for standardized allergens: whole egg, egg white, egg yolk; YFV (1:10 dilution; Biomanguinhos-Fiocruz), and intradermal test (IDT; YFV 0.02 mL, 1:100 dilution) and positive and negative controls. Serum levels of specific IgE (sIgE) for a whole egg, egg white, egg yolk, egg albumin, ovomucoid, lysozyme, and conalbumin (ImmunoCap®; ThermoFisher®) were obtained. Patients sensitized to YFV were submitted to YFV desensitization, and those negatives received YFV (0.5mL) and remained under surveillance for at least one hour. RESULTS: 103 patients were enrolled, 95% under 12 years old. 71% (81/103) of patients had reactions: 80% immediate, 11% mixed, and 9% delayed. There was an association between positive skin test results with YFV and the severity of the reaction (OR:7.64; 95%CI:1.61-36.32; p = 0,011). Only the presence of sIgE to ovomucoid was associated with clinical symptoms (p = 0,025). Thirty patients underwent the YFV desensitization protocol. CONCLUSION: There is a relationship between the positivity of the egg's components and the severity of the clinical reaction. Furthermore, the relationship between the positivity of the tests with the YFV and egg's components may show a tendency to look at ovomucoid and conalbumin, but it is not a certainty. Therefore, further studies are needed to confirm these associations, and for now, the authors still recommend using the vaccine for testing when necessary.

Egg allergy and yellow fever vaccination

Abstract Objective Evaluate biomarkers capable of safely guiding Yellow fever vaccine (YFV) vaccination among individuals suspicious of hen's egg allergy, and identify factors associated with a higher risk for adverse events after immunization (AEAI). Methods Patients underwent skin prick test (SPT) for standardized allergens: whole egg, egg white, egg yolk; YFV (1:10 dilution; Biomanguinhos-Fiocruz), and intradermal test (IDT; YFV 0.02 mL, 1:100 dilution) and positive and negative controls. Serum levels of specific IgE (sIgE) for a whole egg, egg white, egg yolk, egg albumin, ovomucoid, lysozyme, and conalbumin (ImmunoCap®; ThermoFisher®) were obtained. Patients sensitized to YFV were submitted to YFV desensitization, and those negatives received YFV (0.5mL) and remained under surveillance for at least one hour. Results 103 patients were enrolled, 95% under 12 years old. 71% (81/103) of patients had reactions: 80% immediate, 11% mixed, and 9% delayed. There was an association between positive skin test results with YFV and the severity of the reaction (OR:7.64; 95%CI:1.61-36.32; p =0,011). Only the presence of sIgE to ovomucoid was associated with clinical symptoms (p =0,025). Thirty patients underwent the YFV desensitization protocol. Conclusion There is a relationship between the positivity of the egg's components and the severity of the clinical reaction. Furthermore, the relationship between the positivity of the tests with the YFV and egg's components may show a tendency to look at ovomucoid and conalbumin, but it is not a certainty. Therefore, further studies are needed to confirm these associations, and for now, the authors still recommend using the vaccine for testing when necessary.

The inhibitory effect of ovomucoid from egg white on biofilm formation by Streptococcus mutans.

BACKGROUND: Streptococcus mutans, the main pathogen associated with tooth decay, forms cariogenic biofilms on tooth surfaces. Therefore, controlling oral biofilm helps prevent dental caries. Hen's egg is a nutrient-dense food, and egg white is a good source of protein. Ovomucoid is one of the major proteins in egg white, with a 28 kDa molecular weight. The present study aimed to investigate the inhibitory effects of ovomucoid on the biofilm formation of S. mutans by suppressing virulence factors, including bacterial adherence, cellular aggregation and exopolysaccharide (EPS) production. RESULTS: Crystal violet staining showed that biofilm formation by S. mutans was inhibited by ovomucoid at 0.25-1 mg mL-1 levels. Field emission scanning electron microscopy also confirmed this inhibition. In addition, ovomucoid reduced mature biofilm, water-insoluble EPS synthesis and the metabolic activity of bacterial cells in the biofilm. The bacterial adhesion and aggregation abilities of S. mutans were also decreased in the presence of ovomucoid. Ovomucoid downregulated the expression of comDE and vicR genes involved in the two-component signal transduction system and gtfA and ftf genes involved in EPS production. CONCLUSION: Ovomucoid has the potential for use as an anti-biofilm agent for dental caries treatment because of its inhibitory effects on the virulence factors of S. mutans. © 2023 Society of Chemical Industry.

Generation of an Ovomucoid-Immune scFv Library for the Development of Novel Immunoassays in Hen's Egg Detection.

Hen's egg allergy is the second most common food allergy among infants and young children. The possible presence of undeclared eggs in foods poses a significant risk to sensitized individuals. Therefore, reliable egg allergen detection methods are needed to ensure compliance with food labeling and improve consumer protection. This work describes for the first time the application of phage display technology for the generation of a recombinant antibody aimed at the specific detection of hen's ovomucoid. First, a single-chain variable fragment (scFv) library was constructed from mRNA isolated from the spleen of a rabbit immunized with ovomucoid. After rounds of biopanning, four binding clones were isolated and characterized. Based on the best ovomucoid-binding candidate SR-G1, an indirect phage enzyme-linked immunosorbent assay (phage-ELISA) was developed, reaching limits of detection and quantitation of 43 and 79 ng/mL of ovomucoid, respectively. The developed ELISA was applied to the analysis of a wide variety of food products, obtaining a good correlation with a commercial egg detection assay used as a reference. Finally, in silico modeling of the antigen-antibody complex revealed that the main interactions most likely occur between the scFv heavy chain and the ovomucoid domain-III, the most immunogenic region of this allergen.

The Combination of Binding Avidity of Ovomucoid-Specific IgE Antibody and Specific IgG4 Antibody Can Predict Positive Outcomes of Oral Food Challenges during Stepwise Slow Oral Immunotherapy in Children with Hen's Egg Allergy.

To increase the prediction accuracy of positive oral food challenge (OFC) outcomes during stepwise slow oral immunotherapy (SS-OIT) in children with a hen's egg (HE) allergy, we evaluated the predictive value of the combination of antigen-specific IgE (sIgE) with antigen binding avidity and sIgG4 values. Sixty-three children with HE allergy undergoing SS-OIT were subjected to repeated OFCs with HE. We measured the ovomucoid (OVM)-sIgE by ImmunoCAP or densely carboxylated protein (DCP) microarray, sIgG4 by DCP microarray, and the binding avidity of OVM-sIgE defined as the level of 1/IC50 (nM) measured by competitive binding inhibition assays. The OFC was positive in 37 (59%) patients undergoing SS-OIT. Significant differences in DCP-OVM-sIgE, CAP-OVM-sIgE, I/IC50, DCP-OVM-sIgG4, the multiplication products of DCP-OVM-sIgE, and the binding avidity of DCP-OVM-sIgE (DCP-OVM-sIgE/IC50) and DCP-OVM-sIgE/sIgG4 were compared between the negative and positive groups (p < 0.01). Among them, the variable with the greatest area under the receiver operating characteristic curve was DCP-OVM-sIgE/IC50 (0.84), followed by DCP-OVM-sIgE/sIgG4 (0.81). DCP-OVM-sIgE/IC50 and DCP-OVM-sIgE/sIgG4 are potentially useful markers for the prediction of positive OFCs during HE-SS-OIT and may allow proper evaluation of the current allergic status in the healing process during HE-SS-OIT.

Transcription activator-like effector nuclease-mediated deletion safely eliminates the major egg allergen ovomucoid in chickens.

Among the major egg allergens, ovomucoid (OVM) is very stable against heat and digestive enzymes, making it difficult to remove physiochemically and inactivate allergens. However, recent genome editing technology has made it possible to generate OVM-knockout chicken eggs. To use this OVM-knockout chicken egg as food, it is important to evaluate its safety as food. Therefore, in this study, we examined the presence or absence of mutant protein expression, vector sequence insertion, and off-target effects in chickens knocked out with OVM by platinum TALENs. The eggs laid by homozygous OVM-knockout hens showed no evident abnormalities, and immunoblotting showed that the albumen contained neither the mature OVM nor the OVM truncated variant. Whole genome sequencing (WGS) revealed that the potential TALEN-induced off-target effects in OVM-knockout chickens were localized in the intergenic and intron regions. The WGS information confirmed that plasmid vectors used for genome editing were only transiently present and did not integrate into the genome of edited chickens. These results indicate the importance of safety evaluation and reveal that the eggs laid by this OVM knockout chicken solve the allergy problem in food and vaccines.

Pulsed Electric Field-Assisted Alcalase Treatment Reduces the Allergenicity and Eliminates the Antigenic Epitopes of Ovomucoid.

Physically assisted chemical modifications can effectively reduce the allergenicity of ovomucoid (OVM). However, only a few studies have used pulsed electric field (PEF)-assisted alcalase hydrolysis to reduce the allergenicity of OVM. Herein, we investigated the effect of PEF-assisted alcalase treatment on the spatial conformation, allergenicity, and antigenic epitopes of OVM based on multispectroscopic analyses, bioinformatics, and mass spectrometry. The results showed that PEF-assisted alcalase treatment promoted the hydrolysis of OVM; moreover, the α-helix content and surface hydrophobicity of OVM significantly decreased, which disordered its spatial conformation and weakened its intermolecular interactions. Additionally, enzyme-linked immunosorbent assay (ELISA) results showed that the PEF-assisted alcalase treatment significantly reduced the binding levels of IgE and IgG1, which were 47.66 and 36.41%, respectively. Finally, eight epitopes of OVM were obtained by immunoinformatic tools. Nano-high performance liquid chromatography coupled to tandem mass spectrometry (nano-HPLC MS/MS) results showed that the hydrolysate of OVM and alcalase (HOVM) had nine more peptide-containing epitopes than the hydrolysate of PEF-treated OVM and PEF-treated alcalase (HOVM-PP'), indicating that PEF could promote the elimination of linear epitopes in OVM, thereby reducing OVM allergenicity.

The Heterogeneity of Ovomucoid-Specific IgE Idiotype Is Associated With Egg Allergy Symptom Severity.

Immunoglobulin E (IgE)-mediated egg allergy presents as one of the most common food allergies. The level of specific IgE (sIgE) antibody is widely used as an important in vitro diagnostic indicator. However, sIgE antibody levels are often inconsistent with the clinical manifestations of patients. The heterogeneity of egg-specific IgE idiotypes (sIgE-IDs) may help reflect clinical egg allergy severity. Eight peptides were synthesized, corresponding to the linear epitopes of ovomucoid (OVM). The sIgE-IDs of egg-allergic patients were detected by enzyme-linked immunosorbent assay. Fresh peripheral blood was collected from patients with different heterogeneity strength of sIgE-ID, and egg extract was used as a stimulus to the basophil activation test (BAT). RBL-2H3 cells were sensitized with serum with different strength of sIgE-ID heterogeneity and the release rate of ß-hexosaminidase was calculated. Among 75 patients with egg allergy, 24% had sIgE for all epitopes and 85% had sIgE for at least one epitope. Analysis of individual patients revealed differences in epitope recognition patterns among the patients, that is, heterogeneity in sIgE-ID. More importantly, the number of IgE-positive peptides had a strong correlation with allergic symptoms in egg-allergic patients (r = 0.706). BAT and RBL-2H3 cell degranulation confirmed that higher sIgE-ID heterogeneity strength was more effective in inducing effector cell responses. Our results suggest that the greater the heterogeneity strength of OVM-sIgE-ID, the more severe the allergic symptoms.

Mechanistic studies of polyphenols reducing the trypsin inhibitory activity of ovomucoid: Structure, conformation, and interactions.

Ovomucoid (OVM) is a critical anti-nutritional factor in egg, which may reduce nutrient utilization. In this study, the effects of polyphenols on the trypsin inhibitory activity (TIA) of OVM were investigated by exploring the structural changes and interaction mechanisms. The results found that TIA decreased to 62.34% and 90.41% as epigallocatechin gallate (EGCG) and gallic acid (GA) were added individually. EGCG and GA interacted with OVM via static quenching and hydrophobic interaction. They induced a transition of OVM conformation from disorder to order. Infrared and fluorescence quenching analysis showed that the interaction between EGCG or GA and OVM was spontaneous, and hydrophobic interaction was the predominant force. The mechanism suggested that polyphenols affect the protein conformation by spontaneously binding to OVM in hydrophobic interactions, and lowering the TIA through reduced hydrophobicity. In summary, EGCG may be a promising OVM trypsin activity inactivator, which could also guarantee safety of egg products.

Caco-2 Cell Response Induced by Peptides Released after Digestion of Heat-Treated Egg White Proteins.

The heat treatment of food proteins induces structural modifications that influence their interaction with human fluids and cells. We aimed to evaluate the Caco-2 cell response induced by peptides produced after digestion of heat-treated egg white proteins. In vitro digestion of ovalbumin (OVA), ovomucoid (OM), and lysozyme (LYS), untreated or previously heated, was performed. The digestibility of proteins and the response of Caco-2 cells exposed to peptides (<10 kDa) generated during digestion were evaluated. Intact OVA and LYS persisted after the digestion of native proteins, whereas OM was completely hydrolysed. A heat treatment at 65 °C for 30 min did not alter the digestibility of OVA, whereas at 90 °C for 3 min, protein degradation was favoured. The digestibility of OM and LYS was not affected by heat treatment. Peptides derived from OVA and OM digestion induced IL-6 and IL-8 production. OVA and LYS digestion promoted the expression of Tslp, and Il6 and Il33, respectively. A heat treatment prior to OVA digestion reduced IL-6 production and Tslp expression. It was concluded that heat treatments can reduce the release of OVA-derived peptides, but not OM and LYS, with proinflammatory activity during digestion.

Guided Gradual Egg-Tolerance Induction in Hen's Egg Allergic Children Tolerating Baked Egg: A Prospective Randomized Trial.

Background: Over the last few years, studies have shown that the majority of egg allergic children tolerate baked egg (e.g., cake), and that consuming baked egg accelerates the resolution of egg allergy. However, few prospective studies demonstrate the step-wise reintroduction of egg at home after developing baked egg tolerance. Although this could have a positive impact on the children's quality of life and nutrition. Additionally, research supporting the theoretical concept that heating in the presence or absence of wheat causes reduced allergenicity of egg proteins is limited. Objective: To investigate the clinically most favorable duration of gradual egg-tolerance induction in baked egg tolerant children at home, with regard to complete raw egg tolerance. Methods: Baked egg tolerant children above 12 months of age were randomly assigned to a short- or long arm protocol. In the short arm, egg-tolerance induction was studied over 18 months compared to 30 months in the long arm. Children were guided through this protocol involving the step-wise introduction of increasingly allergenic forms of egg starting with baked egg offered as cake, followed by hard-boiled egg, omelet/waffle/pancake, soft-boiled egg, and finally raw egg. We hereby designed this protocol based on the influence of thermal processing in the presence or absence of wheat on egg proteins, as investigated by ELISA, SDS-PAGE, and immunoblotting. At inclusion, children either passed an in-hospital cake challenge or had ovomucoid sIgE ≤1.2 kUA/L, which was considered safe for introduction at home. Results: Gel electrophoresis revealed that the ovalbumin band became weaker with heating, while the ovomucoid band remained stable. In accordance, the IgE-binding to ovalbumin decreased with extensive heating, as opposed to ovomucoid. However, heating in the presence of wheat led to a decreased IgE reactivity to ovomucoid. Of the 78 children in the intention-to-treat group, 39 were randomized to each arm. Fifty-eight children reached the raw egg tolerance endpoint, of which 80% were in the short arm and 69% in the long arm. Within the short arm, the median time to raw egg tolerance was 24 months (95% CI, 21-27 months) compared to 30 months (95% CI, 28-32 months) in the long arm (p = 0.005). No grade IV reactions or cases of eosinophilic esophagitis were observed. The short arm was considered to be non-inferior to the long arm. Conclusion: Our gradual short arm protocol appears to be safe and allows clinicians to guide baked egg tolerant children toward raw egg tolerance at home. The allergenicity of the egg proteins was affected by heating temperature and duration, as well as the presence of wheat.

Novel nanocomposite of spiky-shaped gold nanourchins/ titanium dioxide/nafion for amplified signal and efficient electrochemiluminescence detection of ovomucoid.

This work reports on the first electrochemiluminescence (ECL) immunosensor employing a novel nanostructured composite of titanium dioxide (TiO2) and gold nanourchins (AuNU) to detect protein allergen Ovomucoid (Ovm) found in eggs. TiO2 and AuNU were dispersed in Nafion and drop-casted onto SPGE with Tris(2,2'-bipyridyl)-ruthenium (II) ([Ru(bpy)3]2+) and tri-n-propylamine (TPrA) served as strong luminophore/co-reactant pairs as a source of ECL signals. The linear range, limit of detection, reproducibility and practical applications of the sensor were assessed. The fabricated ECL immuosensor produced a promising limit of detection of as low as 0.01 pg/mL. Two linear ranges of 0.01-50 pg/mL and 100-750 pg/mL with corresponding correlation coefficients of R2 = 0.99136 and R2 = 0.97829) respectively, were determined. Despite its simple fabrication method, this label-free immunosensor also showcased excellent selectivity, reproducibility, interference-resistance and yielded outstanding recoveries between 97.42 and 104.05% of Ovm analysis in spiked real food samples.

Pasteurization induced protein interaction decreased the potential allergenicity of ovalbumin and ovomucoid in egg white.

BACKGROUND: Approximately 9.9% of young children in China suffer from egg allergies. Ovalbumin (OVA) and ovomucoid (OVM) are both the main allergens with higher allergenicity in egg white. The previous studies mainly focused on the effects of pasteurization on the structure and allergenicity of the isolated protein itself. The effects of the interaction between OVA and OVM on their spatial structure and allergenicity under pasteurization are still unclear. Therefore, in this study, the spectroscopic, immunological, and cytological methods were used to investigate the effects on OVA and OVM by their interactions which were induced by the following pasteurization, heating for 10 min at 60, 65, and 70 °C, respectively. RESULTS: Results indicated that OVA and OVM could form macromolecular aggregates by their interaction at 70 °C, and their solubility was decreased while turbidity was increased. The spatial structures of OVA and OVM were both changed by their interaction, when pasteurization temperature was at 70 °C the exposure of their hydrophobic groups and α-helix content were decreased while their ß-sheet was increased. The potential allergenicity of OVA and OVM was also changed, which showed that the immunoglobulin G (IgG)-binding ability of OVA and OVM could be increased, and their IgE-binding ability was decreased a bit. The releases of interleukin 4 (IL-4), IL-6, ß-HEX, histamine and tumor necrosis factor alpha (TNF-α) from OVA-OVM-induced KU812 cells were all decreased at 70 °C. CONCLUSION: Therefore, according to the results, if the liquid egg products were pasteurized for 10 min, the temperature of 70 °C should be carefully considered. © 2022 Society of Chemical Industry.

Effects of Superheated Steam Treatment on the Allergenicity and Structure of Chicken Egg Ovomucoid.

The aim of this study was to explore the effects of an emerging and efficient heating technology, superheated steam (SS), on the allergenicity and molecular structure of ovomucoid (OVM). OVM was treated with 120-200 °C of SS for 2 to 10 min. The allergenicity (IgG/IgE binding abilities and cell degranulation assay) and molecular structure (main functional groups and amino acids modification) changes were investigated. The IgG-binding ability of OVM decreased and the releases of ß-hex and TNF-γ were inhibited after SS treatment, indicating that the protein allergenicity was reduced. Significant increases in oxidation degree, free SH content and surface hydrophobicity were observed in SS-treated OVM. The protein dimer and trimer appeared after SS treatment. Meanwhile, obvious changes occurred in the primary structure. Specifically, serine can be readily modified by obtaining functional groups from other modification sites during SS treatment. Moreover, the natural OVM structure which showed resistance to trypsin digestion was disrupted, leading to increased protein digestibility. In conclusion, SS-induced OVM aggregation, functional groups and amino acids modifications as well as protein structure alteration led to reduced allergenicity and increased digestibility.

A phage virus-based electrochemical biosensor for highly sensitive detection of ovomucoid.

Whole peptide-displayed phage particles are promising alternatives to antibodies in sensor development; however, greater control and functionalization of these particles are required. In this study, we aimed to identify and create highly sensitive and selective phage-based electrochemical biosensors for detecting ovomucoid, a known food allergen. Phage display was performed using two different phage libraries (cyclic and linear form of peptides), which displayed affinity peptides capable of binding specifically to ovomucoid. Throughout the biopanning, two phage clones that displayed both peptides (CTDKASSSC and WWQPYSSAPRWL) were selected. After the characterization of their binding affinities, both whole phage particles were covalently attached to a gold electrode using crosslinking chemistry (MUA-EDC/NHS and Sulfo-LC/SPDP); the developed phage sensor was characterized using cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). The cyclic peptide-displayed phage sensor modified using EDC/NHS chemistry exhibited significantly better binding affinity (Kd = 2.36 ± 0.44 µg/mL) and limit of detection (LOD, 0.12 µg/mL) for ovomucoid than the linear phage sensor, resulting in good reproducibility and recovery, even in an actual egg and white wine samples. This approach may provide an alternative and more efficient way of sensing food allergens with desirable sensitivity, selectivity, and feasibility in food diagnostic applications.

Adult onset egg allergy: a case report.

BACKGROUND: Egg allergy is one of the most frequent food allergies in childhood while adult onset of egg allergy is a rare condition. CASE PRESENTATION: We report the case of a 30 years old man sent to our center in order to investigate gastrointestinal symptoms occurring since 2 years after egg and derivatives intake. He did not suffer from egg or other food allergies in childhood. He is an active smoker with a contact dermatitis related to nickel and mild allergic rhinoconjunctivitis to grass pollen. Skin prick test and serum specific IgE to egg were performed and revealed sensitization to egg proteins. CONCLUSIONS: Even though IgE-mediated egg allergy affects children, this report witnesses a rare case of adult onset.

Protease Inhibitors Protect Bovine Colostrum or Chicken Egg Growth Factors from Pancreatic Enzyme Digestion in AGS Cells or Colitic Rats.

BACKGROUND: Bovine colostrum (BC) and chicken egg contain proteins possessing growth factor activity. Epidermal growth factor (EGF) provides much of the pro-reparative activity within BC. Clinical use of orally administered peptide growth factors is hampered by digestion from pancreatic proteases. OBJECTIVES: We examined whether adding a protease inhibitor [soybean trypsin inhibitor (SBTI) or ovomucoid] protected bioactivity of BC ± egg or EGF alone against pancreatic digestion using in vitro and in vivo models. METHODS: BC, egg, or EGF alone or in combination with trypsin inhibitors were tested for proliferative (Alamar blue) activity using human gastric adenocarcinoma (AGS) cells, prior to and after incubation with HCl/pepsin and trypsin/chymotrypsin. Data were analyzed using 2-factor ANOVA. Eight groups (n = 10) of adult female Sprague-Dawley rats (mean: 188.3 ± 0.8 g) received 20 mg/kg/d of BC + egg, 100 µg/d of EGF, 5 mg/d ovomucoid, or 10.8 mg/d SBTI, alone or in combination (in 1 mL 3% NaHCO3) by gavage for 9 d and dextran sodium sulfate (DSS; 5% in drinking water) for the final 7 d. Histology, microscopic damage score, and myeloperoxidase (MPO) were assessed and analyzed using 1-factor ANOVA. RESULTS: Proliferative activities of BC, egg, or EGF were reduced 40-57% by HCl/pepsin exposure and further reduced 14-24% by chymotrypsin/trypsin. Co-addition of SBTI or ovomucoid truncated the decrease in proliferative bioactivity caused by chymotrypsin/trypsin by 54-100% (P < 0.01). In vivo study showed oral EGF alone or protease inhibitors given alone were ineffective in reducing DSS damage, whereas SBTI with EGF or ovomucoid with BC + egg improved protective effects on weight gain, disease activity score, colonic MPO, and histology damage by 3-4-fold (P < 0.01). CONCLUSIONS: Studies using AGS, cells, and Sprague-Dawley rats showed the protease inhibitors ovomucoid and SBTI protected BC, egg, and EGF against loss of bioactivity due to pancreatic enzymes and, when given with NaHCO3, enhanced colonic protection against DSS damage.