Authors:
Thomas WR.
Authors notes:
Dordrecht: Springer Science+Business Media; 2015. p. 147-73.
Keywords:
Immune response, IgE titer, T cell responses, Cytokine profiles, Allergen provocation
Abstract
Allergies are mediated by several immunological mechanisms that make different contributions in different patients.
Measurements of TH2 and regulatory T cell responses are poorly standardized and are highly influenced by cell culture conditions and allergen preparations.
There are, however, purified allergens and new techniques that can facilitate direct ex vivo measurements and purified allergens for use.
IgE antibodies can be accurately and reproducibly measured using pure allergens that represent the important specificities and allergen arrays can be used to identify cross-reactivities, and hence, reduce false positives.
IgE binding to most allergens is dominated by a few components that usually bind with the same pattern for most patients, although there are exceptions that are now recognized to provide important information.
Measurements with allergen arrays can also reduce the underestimation of antibody titers due to underrepresentation of the important allergen components.
Furthermore, IgE titers should be analysed preferably as continuous variables or if cut offs are used for thresholds the titers should reflect a high probability of substantive atopy and these titers differ for different allergens.
The IgE value that has historically been used to indicate reaction sensitivity, 0.35 IU/mL, is the historic reaction sensitivity for IgE measurements and is a trivial amount of antibody for many allergens but a significant amount for others.
Positive skin test responses can be readily elicited in subjects with trivially low IgE titers and no history of allergic disease and are thus a poor measure of atopy.
The type of immune responses elicited by different allergens, as shown by IgE and IgG subclass titers and, from limited data, T cell responses to different allergens differ in memory cell phenotypes and cytokine profiles.
There is much from these considerations that can be applied to improve the design and analysis of bioinformatic studies.