Microbiology Practice Exam

Where is Immunoglobulin E (IgE) primarily found?

1. On macrophages

2. On lymphocytes

3. On basophils

4. On neutrophils

The correct answer is: On basophils

Immunoglobulin E (IgE) is primarily associated with basophils and mast cells, playing a crucial role in the body’s defense against parasitic infections and in the allergic response. IgE binds to specific receptors on the surface of basophils, promoting their activation and the release of histamines and other chemicals that are involved in allergic reactions. This is especially important in conditions such as asthma and hay fever, where IgE facilitates the response to allergens. While macrophages are key players in the immune system, involved in phagocytosis and antigen presentation, they do not primarily express IgE. Lymphocytes, which include T cells and B cells, are more related to cellular and humoral immune responses but do not mainly express IgE on their surface. Neutrophils are essential for the innate immune response, particularly in fighting bacterial infections, but they are not associated with IgE either. Thus, the presence of IgE specifically on basophils highlights the role of this antibody class in allergic reactions and responses to parasitic infections.