Evidence for circulating IgE complexes in food allergy

Area of Science:

• Immunology
• Gastroenterology
• Allergy Research

Background:

• Atopic individuals experience antigen entry and immune complex formation post-food ingestion.
• Existing research indicates a link between food challenges and the manifestation of allergic symptoms.

Purpose of the Study:

• To investigate the presence of IgE immune complexes and antigen entry from the gut in patients with asthma, eczema, and arthralgia.
• To evaluate the effect of oral sodium cromoglycate (SCG) on preventing symptoms and immune complex formation.

Main Methods:

• Studied patients with asthma, eczema, and arthralgia, assessing antigen entry and IgE immune complexes before and after food challenge.
• Isolated IgE immune complexes using isokinetic ultracentrifugation gradient for component analysis (antigen-specific IgE, IgG, free antigen).
• Assessed the preventative effects of oral sodium cromoglycate (SCG) on symptoms and immune complex appearance.

Main Results:

• Food-allergic subjects showed IgE and IgG immune complexes post-food challenge, correlating with symptom occurrence.
• Oral SCG pretreatment prevented both symptom development and the appearance of IgE immune complexes.
• SCG administration reduced antigen entry, IgE immune complex formation, and subsequent symptoms.

Conclusions:

• IgE plays a central role in the intestinal mucosa's response to food antigens in atopic individuals.
• SCG demonstrates efficacy in mitigating food allergy symptoms by inhibiting antigen entry and immune complex formation.
• The findings support the hypothesis that IgE-mediated mechanisms are critical in food-induced allergic reactions originating in the gut.