Component resolved diagnosis of egg yolk is an indispensable part of egg allergy

Introduction and objectives It was urgent to explain the role of egg yolk allergen sensitization to the egg allergic population and we would evaluate the diagnostic value of allergen components in whole eggs, including egg white and egg yolk. Materials and methods Firstly, we collected 99 positive and 21 negative sera against egg allergy. Then we used modified enzyme linked immunosorbent assay (ELISA) to survey specific IgE (sIgE) to all-proven and single component in eggs, Ovomucoid (Gal d 1), Ovalbumin (Gal d 2), Ovotransferrin (Gal d 3), Lysozyme C (Gal d 4), Serum Albumin (Gal d 5), and YGP42(Gal d 6) in allergic and non-allergic populations. Last but not least, we studied the sIgE reactivities to egg allergen components by receiver operating characteristic (ROC) analysis. Results Among egg-allergic individuals, nearly 10% were sensitized to five of six egg allergen components, and the cross-reaction frequency between two egg yolk allergens with Gal d 1 was about 30% in the groups diagnosed with egg allergy or non-allergy. The best component-combination diagnosis in egg allergy of Gal d 1+ Gal d 6 demonstrated the largest area under curve (AUC) of 0.994. Conclusions Our results suggested that there were individual differences in allergenicity of different egg allergen components, especially in the samples negative to egg allergy diagnosed but sensitive to egg yolk components. It was indicated that component resolved diagnosis of egg yolk improved the value for egg allergy management indispensably (AU)

Component resolved diagnosis of egg yolk is an indispensable part of egg allergy.

INTRODUCTION AND OBJECTIVES: It was urgent to explain the role of egg yolk allergen sensitization to the egg allergic population and we would evaluate the diagnostic value of allergen components in whole eggs, including egg white and egg yolk. MATERIALS AND METHODS: Firstly, we collected 99 positive and 21 negative sera against egg allergy. Then we used modified enzyme linked immunosorbent assay (ELISA) to survey specific IgE (sIgE) to all-proven and single component in eggs, Ovomucoid (Gal d 1), Ovalbumin (Gal d 2), Ovotransferrin (Gal d 3), Lysozyme C (Gal d 4), Serum Albumin (Gal d 5), and YGP42(Gal d 6) in allergic and non-allergic populations. Last but not least, we studied the sIgE reactivities to egg allergen components by receiver operating characteristic (ROC) analysis. RESULTS: Among egg-allergic individuals, nearly 10% were sensitized to five of six egg allergen components, and the cross-reaction frequency between two egg yolk allergens with Gal d 1 was about 30% in the groups diagnosed with egg allergy or non-allergy. The best component-combination diagnosis in egg allergy of Gal d 1+ Gal d 6 demonstrated the largest area under curve (AUC) of 0.994. CONCLUSIONS: Our results suggested that there were individual differences in allergenicity of different egg allergen components, especially in the samples negative to egg allergy diagnosed but sensitive to egg yolk components. It was indicated that component resolved diagnosis of egg yolk improved the value for egg allergy management indispensably.

Modulation of antigen-induced anaphylaxis in mice by a traditional chinese medicine formula, Guo Min Kang.

A traditional Chinese Medicine (TCM) formula, Guo Min Kang (GMK), has been used in clinics in China for allergic diseases, including type I immediate hypersensitivity, a potentially fatal disease, but its modulatory mechanism remains elusive. The aim of this study was to investigate the modulatory mechanisms of GMK in a mouse model of Ag-induced anaphylaxis. Ag (conalbumin) sensitized mice were treated with either PBS (sham) or GMK before (schedule A) or during (schedule B) sensitization, and various anaphylactic parameters were measured following Ag challenge, including symptom score, cutaneous hypersensitivity response, mast cell degranulation, plasma histamine levels and the levels of specific IgE and T-cell responses. Systemic anaphylaxis was investigated in mice immediately following Ag challenge, and the results showed that GMK-treated mice from both treatment schedules A and B showed significantly reduced symptom scores when compared with the sham-treated group. The reduction in symptom score was associated with a significant reduction in the level of Ag-induced cutaneous immediate hypersensitivity. Also, GMK was able to suppress Ag-induced IgE production and T-cell responses, while it spares mitogen (Con A)-induced T-cell response. Further, treatment of mice with GMK abrogated the levels of Ag-induced histamine release and significantly reduced the number of degranulated mast cells. No effect of GMK was observed on the levels of total IgE and plasma histamine in naive mice. These results provide a basis for the modulation effect of GMK and suggest a potential utility of GMK as a prophylactic and therapeutic agent.

Allergenic activity of heated and ovomucoid-depleted egg white.

BACKGROUND: No egg white products have been clearly proven to be hypoallergenic. The role of egg white proteins in allergic reactions to eggs is still debatable. OBJECTIVE: This study was designed to determine the importance of ovomucoid, an egg white protein, in the development of allergies to egg white. METHODS: We performed a double-blind, placebo-controlled food challenge in subjects with high levels of IgE antibodies for egg white to compare the allergenicities of heated and ovomucoid-depleted egg white, freeze-dried egg white, and heated egg white. Levels of IgE antibodies for egg white, ovomucoid, ovalbumin, ovotransferrin, and lysozyme were measured in serum by RAST. RESULTS: Twenty-one of 38 subjects with positive challenge responses to freeze-dried egg white had negative challenge responses to heated egg white, whereas 16 of 17 subjects (94.1%) with positive responses to heated egg white did not respond to the heated and ovomucoid-depleted egg white challenge. The subjects with positive challenge responses to freeze-dried egg white tended to have higher IgE antibody values to ovomucoid than those with negative responses. IgE antibody levels to ovomucoid were significantly higher in subjects with positive responses to a challenge with heated egg white than in those with no response. There were no significant differences in the levels of IgE antibodies to the other proteins, except ovomucoid, in the negative-response and positive-response groups in challenge tests with freeze-dried and heated egg white. CONCLUSION: The heated and ovomucoid-depleted egg white preparation was less allergenic than heated or freeze-dried preparations. Ovomucoid has a more important role in the pathogenesis of allergic reactions to egg white than other proteins in egg white.

Total IgE in newborns treated prophylactically with conalbumin.

Conalbumin has been used as a prophylactic treatment in artificially fed babies to prevent enteritic infections. Conalbumin being a heterologous protein, it could have sensitizing properties. The trial here reported demonstrated that when conalbumin-treated milk was fed to 15 such babies for 60 days the values of total IgE, as determined by the radioimmunoassay method, remained within the normal range.