American Board of Surgery Qualifying Exam (ABS QE) Practice Test

Which type of immune response is primarily associated with eosinophils?

1. Viral infections

2. Parasitic infections and allergies

3. Bacterial infections

4. Fungal infections

The correct answer is: Parasitic infections and allergies

Eosinophils play a critical role in the immune response, particularly in relation to parasitic infections and allergic reactions. These white blood cells are characterized by their ability to respond to larger parasites, such as helminths (worms), that are usually too large to be engulfed by other immune cells. Eosinophils contain granules filled with cytotoxic substances, including proteins and enzymes, that are particularly effective at attacking and breaking down these larger pathogens. In addition to their role in combating parasitic infections, eosinophils are also involved in the pathophysiology of allergic reactions. Upon exposure to allergens, eosinophils are recruited to tissues where they release mediators that can contribute to inflammation and tissue damage, as seen in conditions such as asthma and allergic rhinitis. The other options do not align with the primary functions of eosinophils. Viral infections are predominantly managed by other components of the immune system, primarily cytotoxic T cells and natural killer cells. Bacterial infections typically engage neutrophils and macrophages. Fungal infections are mainly confronted by phagocytes and, in some instances, T cells. Thus, the association of eosinophils is most closely with parasitic infections and allergies, making this