A Relatively New Form of Therapy for IgE-Mediated Allergic Diseases

Multiple Choice

A relatively new form of therapy for IgE-mediated allergic diseases is the periodic injection of patients with anti-IgE antibody. This antibody binds to the Fc portion of IgE antibodies, and prevents the IgE antibodies from binding to both high affinity and low affinity IgE receptors on inflammatory cells. IgE bound to the high affinity IgE receptor on mast cells and basophils stimulates degranulation of these cells and their production of inflammatory mediators, following antigen encounter. In contrast, the low affinity IgE receptor is expressed on dendritic cells, and functions to trap allergen-IgE complexes for uptake, degradation, and presentation to T cells. Given these functions, individuals treated with this anti-IgE therapy would be expected to show:

A) Reduced symptoms upon allergen encounter and no progressive worsening of disease
B) Reduced symptoms upon allergen encounter, but rebound to severe disease if therapy is discontinued
C) Beneficial effects for allergic asthma, but no effect on food or skin allergies
D) No reduction in mucus production in the airways or GI tract
E) A normal response to helminthic parasite infections