A 12-year-old girl with springtime symptoms likely experiences a type I allergic reaction. Which cells are primarily involved?

In the context of a type I allergic reaction, mast cells and basophils play a pivotal role in the pathophysiology of such hypersensitivity responses. Type I hypersensitivity is characterized by an immediate allergic reaction that occurs upon exposure to an allergen. When the allergen first interacts with the immune system, it stimulates B lymphocytes to produce immunoglobulin E (IgE) antibodies. These IgE antibodies bind to the surface of mast cells and basophils, sensitizing them to subsequent exposures to the same allergen.

Upon re-exposure, the allergen cross-links the IgE on the surface of mast cells and basophils, resulting in degranulation of these cells. This degranulation releases various mediators, including histamine, leukotrienes, and prostaglandins, which contribute to the symptoms commonly associated with allergic reactions, such as sneezing, itching, and nasal congestion during springtime. This mechanism explains the immediate onset of symptoms often seen in allergic individuals.

B lymphocytes, while important for the production of IgE antibodies, are not the cells primarily involved in the immediate response associated with type I hypersensitivity. T lymphocytes and neutrophils do not have a direct role in this type