Which cell type is primarily associated with allergic reactions and parasitic infections?

Which cell type is primarily associated with allergic reactions and parasitic infections?

• A. Neutrophil
• B. Basophil
• C. Eosinophil
• D. Lymphocyte

Answer: (C)

Eosinophils are the immune cells most closely associated with allergic reactions and parasitic infections. They circulate in the blood and migrate to sites of inflammation, where their granules release toxic proteins, such as major basic protein, that help kill parasites, especially helminths. Eosinophils are drawn to areas of allergic inflammation by signals from Th2-type responses (like interleukin-5), and they also modulate the inflammatory environment by releasing cytokines and lipid mediators. This dual role—defending against parasites and participating in allergic tissue responses—makes them the cell type most characteristically linked to both conditions. For contrast, neutrophils are the primary responders to bacterial infections, basophils contribute to immediate hypersensitivity through histamine release, and lymphocytes drive adaptive immunity, so they aren’t as specifically tied to parasites and allergic reactions.

Eosinophils are the immune cells most closely associated with allergic reactions and parasitic infections. They circulate in the blood and migrate to sites of inflammation, where their granules release toxic proteins, such as major basic protein, that help kill parasites, especially helminths. Eosinophils are drawn to areas of allergic inflammation by signals from Th2-type responses (like interleukin-5), and they also modulate the inflammatory environment by releasing cytokines and lipid mediators. This dual role—defending against parasites and participating in allergic tissue responses—makes them the cell type most characteristically linked to both conditions. For contrast, neutrophils are the primary responders to bacterial infections, basophils contribute to immediate hypersensitivity through histamine release, and lymphocytes drive adaptive immunity, so they aren’t as specifically tied to parasites and allergic reactions.