Immunotherapy and Food Allergy Quiz

Immunotherapy and Food Allergy

• Immunotherapy-related thresholds with a 95% positive predictive value have been determined for some food allergens.
• In peanut-allergic patients, the threshold sIgE level for peanut antigen is 14 kUA/L (UA = allergen-specific units; 1 unit ≈ 2.4 ng IgE).

Regulatory B Cells (Breg Cells)

• Breg cells support immune tolerance through secretion of anti-inflammatory cytokines IL-10, IL-35, and TGFβ.
• Breg cells are implicated in the development of allergic inflammation.

Sublingual Immunotherapy (SLIT)

• SLIT is an immunotherapeutic method where the food allergen is administered under the tongue in the form of a tablet or drops.

Immunological Responses

• Cytokines IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) act on DCs and other cells to deviate the immune response towards TH2 cell-related allergic responses.
• Cells of the gut and respiratory mucosae and skin that secrete TSLP, IL-25, and IL-33 tend to elicit a TH2 cell-mediated response.

Type 2 Innate Lymphoid Cells (ILC2s)

• ILC2s can be influenced by TSLP, IL-25, or IL-33 to secrete IL-5 and IL-13, which promote TH2 cell-mediated immune responses.

Mast Cells

• Mast cells provide both immediate and delayed release of inflammatory mediators.
• Their activation is a hallmark of atopic disease.

Immunotherapy Outcomes

• Successful immunotherapy has resulted in desensitization over a period of months to a year, and in some cases, has succeeded in establishing sustained unresponsiveness to food allergens.
• Changes to the immune system observed after immunotherapy include increased numbers of anergic antigen-specific T cells, apoptotic antigen-specific T cells, and FOXP3+ Treg cells.
• Over the course of OIT, antigen-specific CD4+ T cells were found to transition from allergic and regulatory phenotypes to anergic and non-allergic phenotypes, in association with decreased allergic symptoms and the development of sustained unresponsiveness.