Clinical immunology
Specific sublingual immunotherapy decreases spontaneous and stimulated basophils degranulation. Preliminary studies

Background: Atopic asthma is a chronic inflammatory disease. The symptoms of asthma and allergy are caused by histamine and numerous cytokines released by basophils degranulated after IgE cross-linking on the cell surface. It is postulated that specific immunotherapy can reverse disturbed immunoregulation as well as suppress basophil activation. Sublingual immunotherapy is postulated to be effective in atopic asthma, although information about its influence on cellular response is limited. The follow-up of the therapy might be measured by basophil’s activation markers e.g. CD203c antigen. Its expression on the cells surface can be measured by flow cytometry.

Aim: The aim of the study was to evaluate CD203c expression on resting and stimulated basophils before and after twelve months sublingual immunotherapy.

Materials and Methods: Venous blood from 6 asthmatic children aged of 8 ± 2.4 years old was analyzed. Antigen CD203c expression on basophils was measured by Allergenicity Kit (Beckman Coulter) with Cytomics FC500 flow cytometer (Beckman Coulter). Patients were allergic to Dermatophagoides pteronyssinus antigens (positive skin prick tests) and were examined before and after twelve months of sublingual immunotherapy (Staloral 300, France). CD203c expression was measured before and after stimulation with specific allergens (Stallergenes, France).

Results: Level of idiopathic activation (presence of CD203c on basophils before allergen stimulation measured by mean fluorescence of fluorescent dye bound with cell surface antigen) in patients before specific immunotherapy was 7.85 ± 5.17 MCF units, whereas after a year of immunotherapy the result was 4.22 ± 1.14 MCF, p < 0.05.
After specific allergen’s stimulation presence of CD203c was detected on 42.26 ± 5.12% basophils, whereas after one year of sublingual immunotherapy expression of CD203c was detected on 25.52 ± 12.8% cells, p < 0.05.

Conclusions: Based on the preliminary results it can be concluded that sublingual immunotherapy is efficient in desensitization of basophils from D. pteronyssinus allergic patients.