Clinical significance of serum IgE

Chung, Hai Lee

Abstract

Many previous studies have proved that human allergic disease resulted from the formation of antibodies belonging to a unique immunoglobulin isotype termed immunoglobulin E (IgE). Most of IgE- producing plasma cells are found in the lymphoid tissue associated with the gastrointestinal and respiratory tracts. IgE may be found free in the mucosal secretions of these tissues, bound to local mast cells, or distributed by the systemic circulation to mast cells and basophils throughout the body. Total serum IgE concentrations tend to be higher in allergic adults and children compared with non-allergic individuals, but the value of total serum IgE as a screening test for allergic disease is limited. Total serum IgE levels are related to the probability of an individual having detectable allergen-specific IgE. Allergen-specific IgE concentrations vary with a person's age, the degree and duration of the recent allergen or cross-reactive allergen exposure. The value of quantitative assays for allergen-specific IgE has been suggested in recent studies. Serum IgE increases in many non-allergic diseases, including infectious and parasitic diseases. The IgE changes appear to be specific to the infectious agents, whereas non-specific in other diseases. The increased serum IgE in some of these conditions probably results from alterations in immune function. This review summarizes the clinical significance of total and allergen-specific IgE examinations in allergic diseases.