cytochalasin-b and Hypersensitivity

The basophil activation test (BAT) based on CD203c upregulation has been validated as a reliable tool for the diagnosis of IgE-mediated allergies. Nevertheless, CD203c-based BAT is hardly comparable with that of CD63-based tests, as the mechanisms of CD203c versus CD63 induction differ considerably. The aim of the present study was to identify potent influencing factors of the CD203c-based BAT and to emphasize differences between CD63 and CD203c detection.. CD203c-based BAT was determined in 82 healthy controls and in 79 allergic patients. The effects of interleukin (IL)-3 and degranulation enhancing substances were investigated and compared with CD63 upregulation. Furthermore, the influence of different storage conditions and incubation times was evaluated and the impact of antiallergic drugs on the test results was assessed.. CD203c and CD63 expression was rapidly upregulated reaching a maximum after 20-30 min. Basophil CD203c upregulation assayed after storage times up to 48 h declined already after 4 h. IL-3 treatment increased CD203c and CD63 baseline levels and decreased basophil CD203c responses in a dose-dependent manner. In contrast, cytochalasin B and latrunculin B did not affect CD203c responses but decreased CD63-based BAT. Finally, therapeutic concentrations of dimetindene and desloratadine did not affect CD203c upregulation.. CD203c-based basophil activation test should be performed preferentially within 4 h after taking the blood samples. Priming and degranulation-enhancing factors are not required for CD203c-based BAT. In contrast to skin testing, CD203c-based BAT can be performed in patients undergoing antiallergic treatment. © 2010 International Clinical Cytometry Society.

Topics: Adult; Anti-Allergic Agents; Antigens, CD; Arthropod Venoms; Basophil Degranulation Test; Basophils; Bridged Bicyclo Compounds, Heterocyclic; Cell Degranulation; Cytochalasin B; Dimethindene; Female; Humans; Hypersensitivity; Immunoglobulin E; Interleukin-3; Loratadine; Male; Middle Aged; Phosphoric Diester Hydrolases; Platelet Membrane Glycoproteins; Pyrophosphatases; Tetraspanin 30; Thiazolidines; Up-Regulation

Eosinophil granule proteins deposition at the site of allergic inflammation contributes to the late-phase reaction of hypersensitivity diseases. In the present communication, we describe the effect of human eotaxin on normal human eosinophil exocytosis measured as degranulation of eosinophil-derived neurotoxin (EDN).. Purified eosinophils were obtained from normal healthy volunteers with the CD16-negative procedure. Purified eosinophils were stimulated with various concentrations of eotaxin and the amount of EDN released was analysed by radioimmunoassay. Flow cytometry was used to examine the surface expression of adhesion molecules on eosinophils.. Eotaxin significantly induced EDN release in a dose-dependent manner. The potency of eotaxin in this effect was equal to that of RANTES, and comparable to that of platelet-activating factor. Eotaxin-induced EDN release was blocked by cytochalasin B in a dose-dependent manner. The surface expression of CD11a, CD11b, CD18 and VLA-4 adhesion molecules on normal human eosinophils were not modulated by eotaxin stimulation.. These results indicate that eotaxin may play an important role not only as a selective chemotaxin for the cell type but also as a secretagogue. Furthermore, they demonstrate a degranulation mechanism(s) involving cytoskeletal changes which is probably independent of the quantitative expression of adhesion molecules.

Topics: CD18 Antigens; Cell Degranulation; Chemokine CCL11; Chemokine CCL5; Chemokines, CC; Chemotactic Factors, Eosinophil; Cytochalasin B; Cytokines; Eosinophil-Derived Neurotoxin; Eosinophils; Exocytosis; Humans; Hypersensitivity; In Vitro Techniques; Integrin alpha4beta1; Integrins; Lymphocyte Function-Associated Antigen-1; Macrophage-1 Antigen; Platelet Activating Factor; Proteins; Receptors, Lymphocyte Homing; Ribonucleases; Signal Transduction