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Asian Pacific Journal of Allergy and... Mar 2024There are no indices to monitor desensitization by low-dose egg oral immunotherapy (eOIT).
BACKGROUND
There are no indices to monitor desensitization by low-dose egg oral immunotherapy (eOIT).
OBJECTIVE
We aimed to examine the relationship between desensitization by low-dose eOIT and the changes in allergen-specific immunoglobulin E (IgE) and IgG4 levels.
METHODS
We carried out low-dose eOIT in 31 patients with severe egg allergy in our previous two studies. After 4 months of treatment, the patients with no observed allergic symptoms in response to the open hard-boiled egg white challenge tests were classified as the negative group, and the remaining patients, the positive group. The fold-difference levels were calculated using 10 Log (Titer after eOIT/Titer before eOIT).
RESULTS
The 28 patients who completed eOIT with sufficient serum collected before and after eOIT were analyzed. The median fold-difference levels of ovomucoid-specific IgE in the negative and positive groups were 0.819 and 0.953, respectively (P = 0.082). The median fold-difference levels of ovalbumin-specific IgG4 in the negative and positive groups were 2.01 and 1.29, respectively (P = 0.057). In the receiver-operating characteristic curves, the area under the curves of fold-difference ovomucoid-specific IgE and ovalbumin-specific IgG4 were 0.701 and 0.719, respectively. The challenge positive predictive values of fold-difference ovomucoid-specific IgE and ovalbumin-specific IgG4 were 83.8% (cut-off point: 0.934) and 77.8% (cut-off point: 1.87), respectively. Moreover, the challenge positive predictive value in patients with both 0.934 < ovomucoid-specific IgE and ovalbumin-specific IgG4 <1.87 was 100%.
CONCLUSIONS
The fold-difference levels of allergen-specific IgE and IgG4 in serum are considered useful for monitoring desensitization by low-dose OIT.
Topics: Humans; Immunoglobulin G; Ovalbumin; Ovomucin; Treatment Outcome; Desensitization, Immunologic; Immunoglobulin E; Allergens
PubMed: 33865297
DOI: 10.12932/AP-100620-0877 -
Poultry Science Feb 2021Ovomucoid is a major egg white protein which is considered as the most dominant allergen in chicken eggs. Owing to the difficulty of separating ovomucoid from egg...
Ovomucoid is a major egg white protein which is considered as the most dominant allergen in chicken eggs. Owing to the difficulty of separating ovomucoid from egg whites, researchers have adopted genetic deletion for development of hypoallergenic eggs. Previously, we used CRISPR/Cas9 to establish chickens with ovomucoid gene (OVM) mutations, but it remained unknown whether such hens could produce eggs at maturity. Here, we have reported on eggs laid by OVM-targeted hens. Except for watery egg whites, the eggs had no evident abnormalities. Real-time PCR revealed alternative splicing of OVM mRNA in hens, but their expression was limited. Immunoblotting detected neither mature ovomucoid nor ovomucoid-truncated splicing variants in egg whites. Sixteen chicks hatched from 28 fertilized eggs laid by OVM-targeted hens, and fourteen of the sixteen chicks demonstrated healthy growth. Taken together, our results demonstrated that OVM knockout could almost completely eliminate ovomucoid from eggs, without abolishing fertility. Thus, the eggs developed in this study have potential as a hypoallergenic food source for most patients with egg allergies.
Topics: Allergens; Animals; Chickens; Egg White; Eggs; Female; Gene Deletion; Male; Mutation; Oviposition; Ovomucin; Ovum
PubMed: 33518096
DOI: 10.1016/j.psj.2020.10.026 -
Clinical and Experimental Allergy :... Dec 2020Although hen's egg allergy is more prevalent in children, up to 0.6% of adults from different European countries suffer from a persistent or newly onset hen's egg...
BACKGROUND
Although hen's egg allergy is more prevalent in children, up to 0.6% of adults from different European countries suffer from a persistent or newly onset hen's egg allergy, making accurate diagnosis in adults necessary. However, sensitization to hen's egg extracts, components and linear epitopes is solely studied in children.
METHODS
Hen's egg allergic (n = 16) and tolerant (n = 19) adults were selected by sensitization towards recombinant components rGal d 1 and/or 3. Sensitization profiles towards egg white and yolk extract and the native components Gal d 1, 2, 3 and 4 were respectively evaluated with the ImmunoCAP or the EUROLINE system. Characterization of linear epitopes was performed with a peptide microarray containing 15mer peptides representing the entire sequence of mature Gal d 1 and 3.
RESULTS
Overall, sIgE titres against hen's egg extracts and single components overlapped largely between allergic and tolerant adults. Although the median sIgE/sIgG4 ratio to Gal d 1 was increased in allergic adults, the range was comparable between both groups. Clinically relevant sensitization to Gal d 1 was confirmed by sIgE-binding to the linear epitopes aa30-41, aa39-50 or aa84-95 in 6/13 allergic adults, mainly suffering from objective symptoms. In comparison, these epitopes were recognized by 1/15 tolerant patient. Only a few linear epitopes were detected for Gal d 3, suggesting a greater importance of conformational epitopes for the recognition of Gal d 3.
CONCLUSION AND CLINICAL RELEVANCE
Specific IgE-binding to linear epitopes of Gal d 1 is highly specific in identifying hen's egg allergic adults with objective symptoms.
Topics: Adult; Aged; Biomarkers; Egg Hypersensitivity; Egg Proteins; Female; Humans; Immunodominant Epitopes; Immunoglobulin E; Immunologic Tests; Male; Microarray Analysis; Middle Aged; Ovomucin; Predictive Value of Tests; Recombinant Proteins; Retrospective Studies; Young Adult
PubMed: 32909666
DOI: 10.1111/cea.13730 -
International Journal of Biological... Nov 2020Intestinal dysfunction, which may cause a series of metabolic diseases, has become a worldwide health problem. In the past few years, studies have shown that consumption... (Review)
Review
Intestinal dysfunction, which may cause a series of metabolic diseases, has become a worldwide health problem. In the past few years, studies have shown that consumption of poultry eggs has the potential to prevent a variety of metabolic diseases, and increasing attention has been directed to the bioactive proteins and their peptides in poultry eggs. This review mainly focused on the biological activities of an important egg-derived protein named ovomucin. Ovomucin and its derivatives have good anti-inflammatory, antioxidant, immunity-regulating and other biological functions. These activities may affect the physical, biological and immune barriers associated with intestinal health. This paper reviewed the structure and the structure-activity relationship of ovomucin,the potential role of ovomucin and its derivatives in modulation of intestinal health are also summarized. Finally, the potential applications of ovomucin and its peptides as functional food components to prevent and assist in the pretreatment of intestinal health problems are prospected.
Topics: Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Antineoplastic Agents; Antioxidants; Chickens; Egg Proteins; Eggs; Gastrointestinal Microbiome; Intestinal Mucosa; N-Acetylneuraminic Acid; Ovomucin; Peptides; Poultry; Structure-Activity Relationship
PubMed: 32569696
DOI: 10.1016/j.ijbiomac.2020.06.148 -
Journal of Applied Glycoscience 2020Ovomucin, a hen egg white protein, is characterized by its hydrogel-forming properties, high molecular weight, and extensive -glycosylation with a high degree of...
Ovomucin, a hen egg white protein, is characterized by its hydrogel-forming properties, high molecular weight, and extensive -glycosylation with a high degree of sialylation. As a commonly used food ingredient, we explored whether ovomucin has an effect on the gut microbiota. Glycan analysis revealed that ovomucin contained core-1 and 2 structures with heavy modification by -acetylneuraminic acid and/or sulfate groups. Of the two mucin-degrading gut microbes we tested, grew in medium containing ovomucin as a sole carbon source during a 24 h culture period, whereas did not. Both gut microbes, however, degraded ovomucin -glycans and released monosaccharides into the culture supernatants in a species-dependent manner, as revealed by semi-quantified mass spectrometric analysis and anion exchange chromatography analysis. Our data suggest that ovomucin potentially affects the gut microbiota through -glycan decomposition by gut microbes and degradant sugar sharing within the community.
PubMed: 34354526
DOI: 10.5458/jag.jag.JAG-2019_0020 -
Allergy Oct 2020Egg-white ovomucoid, that is, Gal d 1, is associated with IgE-mediated allergic reactions in most egg-allergic children. Epitope-specific IgE levels have been correlated...
BACKGROUND
Egg-white ovomucoid, that is, Gal d 1, is associated with IgE-mediated allergic reactions in most egg-allergic children. Epitope-specific IgE levels have been correlated with the severity of egg allergy, while emerging evidence suggests that other antibody isotypes (IgG , IgG , IgA, and IgD) may have a protective function; yet, their epitope-specific repertoires and associations with atopic comorbidities have not been studied.
METHODS
Bead-based epitope assay (BBEA) was used to quantitate the levels of epitope-specific (es)IgA, esIgE, esIgD, esIgG , and esIgG antibodies directed at 58 (15-mer) overlapping peptides, covering the entire sequence of ovomucoid, in plasma of 38 egg-allergic and 6 atopic children. Intraclass correlation (ICC) and coefficient of variation (CV) were used for the reliability assessment. The relationships across esIgs were evaluated using network analysis; linear and logistic regressions were used to compare groups based on egg allergy status and comorbidities.
RESULTS
BBEA had high reliability (ICC >0.75) and low variability (CV <20%) and could detect known IgE-binding epitopes. Egg-allergic children had lower esIgA (P = .010) and esIgG (P = .016) and higher esIgE (P < .001) and esIgD (P = .015) levels compared to the atopic controls. Interestingly, within the allergic group, children with higher esIgD had decreased odds of anaphylactic reactions (OR =0.48, P = .038). Network analysis identified most associations between esIgE with either esIgG or esIgD; indicating that IgE-secreting plasma cells could originate from either sequential isotype switch from antigen-experienced intermediate isotypes or directly from the IgD B cells.
CONCLUSIONS
Collectively, these data point toward a contribution of epitope-specific antibody repertoires to the pathogenesis of egg allergy.
Topics: Allergens; Child; Epitopes; Humans; Immunoglobulin A; Immunoglobulin D; Immunoglobulin E; Immunoglobulin G; Ovomucin; Reproducibility of Results
PubMed: 32391917
DOI: 10.1111/all.14357 -
Jornal de Pediatria 2020To assess the frequency of baked egg tolerance in IgE-mediated egg allergy patients through the oral food challenge and to assess the tolerance predictability of...
OBJECTIVE
To assess the frequency of baked egg tolerance in IgE-mediated egg allergy patients through the oral food challenge and to assess the tolerance predictability of different skin prick tests, as well as specific serum IgE measurement to egg proteins.
METHODS
In this cross-sectional study, 42 patients with a diagnosis of egg allergy were submitted to different skin prick tests with egg (in natura, boiled, muffin, ovalbumin, and ovomucoid), and specific IgE to egg white, ovalbumin, and ovomucoid; as well as to the oral food challenge with food containing egg, extensively baked in a wheat matrix.
RESULTS
Of the total, 66.6% of patients tolerated the ingestion of egg-containing foods in the oral food challenge. A comparative analysis with positive and negative oral food challenge found no significant differences regarding age, gender, other food allergies, or even specific skin prick tests and IgE values between the groups.
CONCLUSIONS
The study demonstrated an elevated frequency of baked egg food-tolerant individuals among egg allergy patients. None of the tested markers, skin prick tests, or specific IgE, were shown to be good predictors for identifying baked egg-tolerant patients. The oral food challenge with egg baked in a matrix is central to demonstrate tolerance and the early introduction of baked foods, improving patients' and families' quality of life and nutrient intake.
Topics: Allergens; Cooking; Cross-Sectional Studies; Egg Hypersensitivity; Eggs; Humans; Immune Tolerance; Immunoglobulin E; Ovomucin; Quality of Life; Skin Tests
PubMed: 31513760
DOI: 10.1016/j.jped.2019.08.002