title: Allergen-induced basophil activation: CD63 cell expression detected by flow cytometry in patients allergic to Dermatophagoides pteronyssinus and Lolium perenne.
abstract: BACKGROUND
  In this study, we determined by flow cytometry the percentage of basophils activated after in vitro stimulation by allergens and expressing the CD63 marker. The diagnostic reliability of the technique was assessed as well as its correlation with other in vitro diagnostic parameters.
  
  
  METHODS
  Fifty-three patients suffering from asthma and/or allergic rhinitis following sensitization to Dermatophagoides pteronyssinus and 51 patients sensitized to Lolium perenne were investigated. Twenty-four atopic patients not sensitive to these allergens and 38 healthy subjects were also selected as controls. The basophil activation test determines the percentage of basophils which express CD63 as an activation marker, by means of flow cytometry, after in vitro stimulation with allergen, using double labelling with monoclonal antibody anti-CD63-PE and anti-IgE-FITC.
  
  
  RESULTS
  No differences in basal values (non-activated control) were found between sensitized patients, atopic controls and healthy controls. On the other hand, sensitized patients showed a significantly higher percentage of activated basophils after stimulation by allergens in vitro than both control groups (P < 0.001). We found a significant correlation between skin tests and basophil activation tests (r = 0.72, P < 0.001). We also found a positive and significant correlation between basophil activation tests and histamine release tests (r = 0.80, P < 0.001), allergen-specific sulphidoleukotriene production (r = 0.7, P < 0.001) and the occurrence of serum allergen-specific IgE (r = 0.71, P < 0.001).
  
  
  CONCLUSIONS
  The basophil activation test is a highly reliable technique in the diagnosis of allergy to inhalant allergens. The sensitivity of the basophil activation test was 93.3%, and its specificity 98.4%, when using a cut-off point of 15% activated basophils as positive result.
authors.affiliation: Department of Allergology and Clinical Immunology, Clínica Universitaria de Navarra, School of Medicine, University of Navarra, 31080 Pamplona, Spain.
authors.forename: M L
authors.initials: ML
authors.lastname: Sanz
authors.forename: G
authors.initials: G
authors.lastname: Sánchez
authors.forename: P M
authors.initials: PM
authors.lastname: Gamboa
authors.forename: L
authors.initials: L
authors.lastname: Vila
authors.forename: C
authors.initials: C
authors.lastname: Uasuf
authors.forename: M
authors.initials: M
authors.lastname: Chazot
authors.forename: I
authors.initials: I
authors.lastname: Diéguez
authors.forename: A L
authors.initials: AL
authors.lastname: De Weck
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis*; D039741:Antigens, Dermatophagoides; D015549:Basophil Degranulation Test; D001491:Basophils / Q000276:immunology* / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry / Q000706:statistics & numerical data; D006023:Glycoproteins / Q000276:immunology*; D006636:Histamine Release / Q000276:immunology; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology; D015289:Leukotrienes / Q000096:biosynthesis; D008129:Lolium / Q000276:immunology*; D008297:Male; D008925:Mites / Q000276:immunology*; D010980:Platelet Membrane Glycoproteins / Q000096:biosynthesis*; D012221:Rhinitis, Allergic, Perennial / Q000175:diagnosis / Q000276:immunology*; D060149:Tetraspanin 30
chemical_list: D000485:Allergens; D015703:Antigens, CD; D039741:Antigens, Dermatophagoides; C554586:CD63 protein, human; D006023:Glycoproteins; D016056:Immunodominant Epitopes; D015289:Leukotrienes; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30