Dynamics of basophil reactivity in the patients with allergic rhinitis on the background of allergen-specific immunotherapy

Abstract

BACKGROUND: Allergen-specific immunotherapy (ASIT) helps to reduce spontaneous and to induce basophil reactivity, which is one of the major mechanisms of its effectiveness. A number of studies, though, have not confirmed the informative value of the basophil activation test (BAT), in case of ASIT, with house dust mites, meadow grass pollen, and wasp venom. BAT outcomes are likely to be influenced by the properties of the sensitizing allergen, the duration of ASIT, and the BAT markers that are used.
 AIMS: To evaluate the basophils reactivity in the patients sensitized to weed pollen and treated with allergen-specific therapy.
 MATERIALS AND METHODS: The study involved 60 patients (aged 1655) with allergic rhinitis sensitized to weed pollen. The diagnosis was based on the skin test outcomes as well as on identifying specific antibodies to major allergens of ragweed, wormwood, timothy, and birch. The pre-seasonal ASIT involved water-salted extracts of pollen allergens during 2 years. Clinical symptoms and the immunotherapy effectiveness were evaluated 6 and 18 months after the ASIT started. BATs were made before the treatment, after the first and second courses of pre-seasonal ASIT, which corresponded to zero, the 3rd and the 15th months of the treatment. The activated basophils were identified based on the CRTH2pos CD203brightCD3neg phenotype.
 RESULTS: The first treatment course was completed by 52 patients, while the second one by 43 patients. A statistically significant decrease in spontaneous basophil reactivity was detected only after the second course of ASIT. The decrease in the allergen-induced basophil activation was identified in 67.4% of the samples obtained after the first ASIT course, and in 67.6% of samples taken after the second immunotherapy course. A decrease in the BAT stimulation index (BAT SI) was identified mainly in the patients featuring positive treatment outcomes.
 CONCLUSIONS: ASIT influences on the basophil reactivity indicators in the patients sensitized to weed pollen. The basophil activation test may be considered as a potential predictor of ASIT effectiveness.