Immunological methods in the diagnostic allergy clinical and research laboratory

This chapter overviews clinically used and research methods for the quantification of total and allergen-specific IgE antibodies and allergen-specific IgG antibodies. The performance of immunoassays for these analytes has continued to improve with the availability of new solid-phase matrices, conjugate labeling technology, standardized reference reagents, and data processing methods. One monoclonal antibody-based noncompetitive solid-phase two-site immunoenzymetric assay (IEMA) is described here as the procedure of choice for research investigations of total serum IgE. Because total serum IgE is a regulated analyte as defined by the amended Clinical Laboratory Improvement Act of 1988, licensed clinical laboratories providing this analytical measurement must demonstrate proficiency in an external proficiency survey such as the Diagnostic Allergy (SE) survey conducted by the College of American Pathologists. A modification of the total serum IEMA described above allows the quantification of the level of ''free'' or non-omalizumab-bound IgE in serum. A 1992 study highlighted that venom-specific IgG levels of <3.5 Mg/ml are associated with an increased risk of allergic reactions upon a resting during the first 4 years of immunotherapy with yellow jacket or mixed vespid venoms. In summary, the diagnostic allergy laboratory uses a number of immunoassay methods to measure IgE and IgG antibodies that aid the clinician in the diagnosis and management of individuals with allergic disease. As more is learned about genetic polymorphisms that predispose individuals to allergic disease, molecular biology methods may also be employed in the diagnostic allergy laboratory of the future.