The role of immunoglobulins in allergic disease: IgE and IgG4 immunofluorescent study of adenoid tissue.
Upper airway allergy is a common problem in children. The most frequent tissue removed from children is adenoid tissue. Although conventional stains offer little help in characterization of the allergic response in this tissue, immunohistologic assessment does offer the opportunity to reveal immunoreactants present. Adenoid tissue from 91 allergic and nonallergic children was examined by a dual immunofluorescent method to detect mast cell membrane bound IgE and IgG4. Positive mast cell membrane staining was seen with IgE (FIEMC) but not with IgG4 in adenoid tissue from allergic children. Numerous IgG4 plasma cells were often seen in close relationship to FIEMC in adenoid stroma where blocking function of IgG4 may take place. False-positive FIEMC patients may represent transient or infrequent encounters with allergens. Disparate clinical allergy and tissue FIEMC status may also reflect different genetic control of IgE regulation and antigen (allergen) recognition.