IgEbearing

IgEbearing is a term used in immunology to describe IgE antibodies or cells and complexes in which IgE is presented on the surface of cells or in immune complexes. The most common usage refers to IgE bound to high-affinity FcεRI receptors on effector cells such as mast cells and basophils. In this context, IgE serves to sensitize these cells to allergens; when an appropriate allergen cross-links bound IgE, it triggers degranulation and the release of mediators like histamine, leukotrienes and prostaglandins, contributing to immediate hypersensitivity symptoms. Free IgE in serum is typically rapidly bound to FcεRI on circulating or tissue-resident cells, so the detectable pool is usually small relative to receptor-occupied IgE.

Detection and measurement: IgE-bearing cells can be identified by flow cytometry using antibodies against IgE or FcεRI, or by staining tissue sections for IgE– Fc receptors. Serum IgE concentration is commonly measured by immunoassay. Distinguishing IgE-bearing from non-bound IgE is important for understanding the severity and mechanism of allergic disease.

Clinical relevance: The level and distribution of IgE-bearing compartments correlate with allergic sensitization and risk of reaction. Therapeutic strategies that reduce total IgE or block FcεRI engagement, such as anti-IgE antibodies, aim to reduce receptor occupancy and effector cell activation.

Other contexts: In B cell biology, some developing B cells express membrane-bound IgE (IgE-BCR) during class-switch recombination, a specialized aspect of humoral immunity.