Dose-dependence of hypersensitivity and hyperreactivity
These two stages of allergy are related by the dose-dependent effect of allergens and non-specific inducers. However, hyperreactivity is completely dependent on the degree, intensity of hypersensitivity, therefore, the dose of an allergen or inducer determines only the degree of specific or nonspecific hypersensitivity. The need for high doses of inducers for nonspecific types of allergy is due to the relatively low concentration, expression of cell receptors or activating molecules of humoral factors that respond to them (for example, complement).
Hypersensitivity of cells is easily detected in vitro by their release of mediators, cytokines and enzymes. All leukocytes, if they are sensitized actively (lymphocytes) or passively (with antibodies – granulocytes, platelets) respond to the allergen by the release of these substances and degranulation to low doses of allergens, as well as by change in phenotype, expression of receptors and CD antigens. In some patients, nonspecific inducers, for example drugs with nonspecific hypersensitivity to them, also provoke such a response [12, 13].
The in vivo response to allergens and nonspecific inducers is assessed by the level of hyperreactivity: by the degree of skin reaction (hyperemia, edema, etc.), or reaction of bronchi (bronchospasm), as well as by the clinical symptoms of allergy that it causes (urticaria, rhinorrhea, etc.) It was possible to evaluate hypersensitivity in vivo without hyperreactivity and clinical symptoms after developing in our clinic [7, 8, 9] low-dose allergen-specific nasal and oral-pharyngeal tests that do not cause clinical symptoms, but are recorded by an increase in the level of allergy biomarkers in nasal secretions and oral fluid. Doses of allergens in these tests were reduced by 20-200 times compared with those used in conventional provocative tests, which induce clinical symptoms.