Basophil activation: theoretical aspects and use in the diagnosis of allergic diseases

Diagnostics of allergic diseases is a difficult issue, which requires distinct solutions, since this disorder is very common among the population. The overview focuses on complex diagnostics, including various methods that are most in demand at the present stage. The allergy diagnostics primarily include taking anamnesis, physical examination, instrumental and functional tests. Less often, the provocative tests are used, due to risk of severe adverse reactions. At the present stage, the role of laboratory diagnostics of allergies is growing, since, firstly, there is an increase in difficult-to-diagnose cases that require involvement of the entire medical armamentarium, and, secondly, the sensitivity and specificity of laboratory tests are improving. Among laboratory methods, the most significant are the assessment of the level of specific IgE, and the relatively new basophile activation test. The latter test is the main focus of the present review. It is functional and combines the advantages of provocative tests, during which conditions are created for the interaction of a potential allergen and effector cells of allergic inflammation, keeping safety for the patient. The data on the life cycle of basophils, their expression of membrane receptors, the content of granules, and ability to produce additional inflammatory mediators by the cells are presented. Participation of these cells in pathogenesis of allergic inflammation is being considered. Various mechanisms of basophil activation are discussed, both IgE-mediated and IgE-independent, which are similar in vivo and in vitro. Theoretical aspects of using the in vitro basophil activation test to estimate the hypersensitivity to a wide range of allergens are discussed. High sensitivity and specificity of the test for diagnosing allergies to food, household, pollen, insect and drug allergens are presented. Specific features of the basophil activation test related to the preanalytical, analytical and postanalytical stages of the study are highlighted. The factors influencing evaluation of this method are known. For example, difficulties in interpreting the test may arise while taking glucocorticosteroid hormones, in acute period of inflammation, with severe edema. The possibility of using this test to assess effectiveness of allergen-specific and anti-IgE therapy is being considered. A comparison of the basophil activation test, measurement of specific IgE and skin tests by various parameters related to performance and interpretation of results is carried out. Comprehensive diagnostics of allergic diseases, including usage of pathogenetically determined laboratory methods, will contribute to adequate treatment and, as a result, improve the health of the population.