Retinoic Acid Ameliorates the Severity of Food Allergy under Allergen Exposure in a Mouse Model with Food Allergy.

Effectiveness of retinoic acid (RA) in treating food allergy is not yet clear. Using an allergic mouse model, we examined the amelioration of the severity of food allergy by daily RA intake with allergen or without. Female Balb/c mice were systemically sensitized to egg white (EW) and alum by intraperitoneal injection. Sensitized mice were provided diets supplemented with 0% (non-treated group), 0.1% EW (allergen group), 0.0017% RA (RA group), or 0.1% EW plus 0.0017% RA (RA+allergen group) with 20% casein for 4 wk. Oral food challenge (OFC) and allergic biomarkers were quantified. The decrease in rectal temperature post-OFC was significantly suppressed in the RA and RA+allergen groups compared to those in the non-treated and allergen groups, respectivety. The plasma levels of ovalbumin-specific IgE, IgA and IgG1 at the study endpoint were higher in the allergen and RA+allergen groups than those in the non-treated and RA+allergen groups, respectivety. Plasma ovalbumin-specific IgG2a levels at the study endpoint were significantly higher in the RA+allergen group than those in the RA groups. The supernatant concentrations of interleukin-10 and interferon-γ in the cultured spleen lymphocytes were highest in the RA+allergen group compared to those in the other groups. Thus, continuous intake of RA under allergen exposure ameliorated the severity of food allergy in a mouse model with food allergy.

Stepwise oral immunotherapy for 10 days in an egg-white allergy mouse model did not ameliorate the severity of allergy but induced the production of allergen-specific IgA.

We examined whether the stepwise oral immunotherapy (OIT) for 10 days ameliorates the severity of allergy and the biomarkers in an allergy mouse model. The OIT could not protect anaphylaxis symptoms after allergen challenges but promote the production of antibodies, especially allergen-specific IgA. It was suggested that this OIT influenced the function of immuno response against the allergen. Abbreviations: EW: egg white; IFC: intraperitoneal food challenge; IFN-γ: interferon-γ; IL: interleukin; OVA: ovalbumin; OM: ovomucoid; OFC: oral food challenge; OIT: oral immunotherapy.

Diets Supplemented with 1% Egg White Induce Oral Desensitization and Immune Tolerance in an Egg White-Specific Allergic Mouse Model.

BACKGROUND: The objective of this study was to determine the required concentration of egg white (EW) in the diet to induce oral desensitization and/or immune tolerance within 4 weeks of oral immunotherapy (OIT) in an EW allergic mouse model. METHODS: Female BALB/c mice were systemically sensitized to EW by intraperitoneal injections and subsequently subjected to oral allergen gavage. Sensitized mice were provided 4 weeks of OIT by supplementing with 0 (non-OIT), 0.01, 0.1, or 1% EW in a 20% casein diet. Nonsensitized mice served as the nonallergy group. We performed oral and intraperitoneal EW challenges, assessed vascular permeability in the dorsal skin, and measured allergic biomarkers. RESULTS: The change in rectal temperature after oral challenge was not significantly different between the nonallergy and 1% EW groups, and the frequency of diarrhea in the 1% EW group was lower than that in the non-OIT group. The levels of plasma ovomucoid-specific IgE, IgA, and IgG2a in the 1% EW group at the study endpoint were significantly lower than those in the non-OIT group. IFN-γ and IL-10 secretions of spleen lymphocytes in the 1% EW group were significantly higher than those in the non-OIT group, and the percentage of CD4+Foxp3+ cells in the 1% EW group was higher than that in the non-OIT group. CONCLUSION: These results suggested that diet supplemented with 1% EW can induce oral desensitization and immune tolerance in the EW allergic mouse model.

Low-Dose Oral Immunotherapy Using Low-Egg-Allergen Cookies for Severe Egg-Allergic Children Reduces Allergy Severity and Affects Allergen-Specific Antibodies in Serum.

BACKGROUND: We evaluated the safety and efficacy of low-egg-allergen cookies (LAC) as low-dose oral immunotherapy (OIT) in children with severe egg allergy. We also examined the relationship between mild desensitization by low-dose OIT and serum biomarkers of allergy. METHODS: We enrolled 13 children with egg allergy who could not receive OIT with hard-boiled egg white (EW). For 11 participants, OIT was carried out using LAC for 3-4 months. Open food challenges with hard-boiled EW and blood samplings were performed before and after OIT. Participants were divided into 2 groups: high effect (H-E) and no/low effect (N/L-E). Serum levels of total IgE and egg yolk-, EW-, and ovomucoid (OM)-specific IgE, ovalbumin (OVA)- and OM-specific IgG4, IgA1, and IgA2, and the percentage of CD 203c+ were measured. RESULTS: Allergic severity was reduced in 7 patients, who were assigned to the H-E group. Moreover, no study participants were taken off the intake of LAC during OIT. In the H-E group, OVA-specific IgA2 levels after OIT were significantly higher than before OIT. The ratios of OM-specific IgG4/OM-specific IgE and OM-specific IgA2/OM-specific IgE in the H-E group after OIT were significantly higher than before OIT. CONCLUSION: Our findings suggest that low-dose OIT using LAC is an effective and safe treatment for patients with severe egg allergy.