Allergen-specific IgG show distinct patterns in persistent and transient food allergy

Area of Science:

• Immunology
• Allergy Research
• Cellular Signaling

Background:

• Immediate food allergies are immunoglobulin E (IgE)-mediated.
• Many individuals with detectable allergen-specific IgE do not experience reactions.
• Allergen-specific IgG may play a role in modulating these reactions and natural tolerance.

Purpose of the Study:

• To investigate the role of allergen-specific IgG in food allergy.
• To understand the mechanisms underlying natural tolerance to food allergens.
• To explore the involvement of IgG receptors in mast cell and basophil activation.

Main Methods:

• Measured IgG and IgG isotypes specific to peanut, cow's milk, and egg using ImmunoCAP and ELISA.
• Analyzed IgE and IgG expression on basophils and mast cells via flow cytometry.
• Investigated the effect of FcγRIIα and FcγRIIβ receptor blockade on allergen-induced cell activation.

Main Results:

• Peanut-specific IgG levels were higher in allergic children.
• No significant differences in most IgG isotypes were found for milk or egg allergies, except for higher milk-specific IgG4 in non-allergic children.
• Blocking FcγRIIα or FcγRIIβ receptors did not alter mast cell or basophil activation.

Conclusions:

• Distinct allergen-specific IgG patterns exist for persistent (peanut) versus transient (milk, egg) food allergies.
• FcγRIIα and FcγRIIβ receptors do not appear to mediate allergen-induced mast cell and basophil activation in food allergy or tolerance.