ABSTRACT
Diagnosis of human allergic disease begins with a clinical history and physical examination by the clinician, and high-probability cases are followed with a confirmatory test for sensitization involving allergen-specific IgE measurements by skin test and/or serological assays. This chapter examines laboratory methods used to confirm sensitization (IgE antibody) in humans. The historical evolution of assay design, calibration, and performance is overviewed from manual assays to current state-of-the-art computer-driven autoanalyzers. Allergenic extracts and select molecular components for peanut and hazelnut are currently used clinically to assess the specificity of IgE antibodies to environmental aeroallergens (weeds, grasses, trees, animal epidermals, molds), foods, and injected (drug and venom) allergens. Serological IgE antibody results are shown to be comparable to results generated by skin testing for the aeroallergens, favored over skin testing for food-specific IgE testing due to properties of superior quality control/reproducibility and confirmatory for skin testing used to assess suspected sensitization to venoms and drugs. Finally, assays for other analytes including mast cell tryptase, basophil mediator release and flow cytometry-based assays, precipitins for hypersensitivity pneumonitis, and allergen-specific IgG4 analyses are discussed.
