Skin test results but not serology reflect immediate type respiratory sensitivity: A study performed with recombinant allergen molecules

The diagnosis of type I allergy, an IgE-antibody-mediated hypersensitivity disease affecting more than 25% of the population, is based on the measurem ent of allergen-specific serum IgE levels and provocation testing. Whether the determination of allergen-specific serum IgE levels can replace in vivo provocation testing for allergy diagnosis is a controversial issue. We use d purified recombinant timothy grass and birch pollen allergens to compare by skin prick and nasal provocation testing as well as by serology in vivo sensitivity with antibody-binding capacity in 24 pollen allergic patients a nd eight control individuals. Results from biologic tests were correlated w ith each other and with allergen-specific IgE and IgG(1-4) levels. IgE-reac tive allergens induced immediate skin and nasal reactions, but the intensit y of the allergic tissue reactions was not correlated with either the level s of allergen-specific IgE or the levels of allergen-specific IgG antibodie s. Less frequently detected allergens with low IgE-binding capacity were ab le to induce strong allergic reactions comparable to those caused by major allergens with high IgE-binding capacity. In contrast, skin test and nasal provocation results were significantly correlated (r = 0.63, p < 0.01). Our study thus demonstrates on a molecular level that skin testing provides a better reflection of immediate type respiratory sensitivity than serologic measurements. These results have implications for allergy diagnosis and, in particular, for the selection of relevant allergen components for specific immunotherapy.