Which immunoglobulin is especially implicated in parasitic and allergic reactions?

Which immunoglobulin is especially implicated in parasitic and allergic reactions?

• A. IgA
• B. IgG
• C. IgM
• D. IgE

Answer: (D)

IgE is the antibody specialized for defending against parasites and driving allergic inflammation. It acts by sensiting mast cells and basophils through binding to their high-affinity Fc receptors. When a parasite or an allergen reappears and cross-links the IgE on these cells, they release mediators such as histamine, leukotrienes, and prostaglandins. Those mediators produce the rapid symptoms of an allergic reaction—itch, swelling, bronchoconstriction, and in severe cases anaphylaxis—and help recruit eosinophils to fight parasitic infections. In parasitic responses, IgE-coated parasites are targeted by eosinophils, which release cytotoxic granules to kill the parasite. Other immunoglobulins have different primary roles—IgA at mucosal surfaces, IgG in opsonization and complement activation, IgM as the initial responder and strong agglutinator—whereas IgE is the one most closely tied to parasitic defense and allergic reactions.

IgE is the antibody specialized for defending against parasites and driving allergic inflammation. It acts by sensiting mast cells and basophils through binding to their high-affinity Fc receptors. When a parasite or an allergen reappears and cross-links the IgE on these cells, they release mediators such as histamine, leukotrienes, and prostaglandins. Those mediators produce the rapid symptoms of an allergic reaction—itch, swelling, bronchoconstriction, and in severe cases anaphylaxis—and help recruit eosinophils to fight parasitic infections. In parasitic responses, IgE-coated parasites are targeted by eosinophils, which release cytotoxic granules to kill the parasite. Other immunoglobulins have different primary roles—IgA at mucosal surfaces, IgG in opsonization and complement activation, IgM as the initial responder and strong agglutinator—whereas IgE is the one most closely tied to parasitic defense and allergic reactions.