title: Basophil activation during pollen season in patients monosensitized to grass pollens.
abstract: BACKGROUND
  Basotest is a new basophil-activation test based upon the expression of CD63 (gp53) in the presence of allergens. It is an effective diagnostic test for pollen-allergic patients. However, it is not known whether Basotest results differ during the pollen season.
  
  
  METHODS
  We examined the activation of basophils by Basotest in 13 patients sensitized only to grass pollen, before and during the pollen season, in order to assess whether Basotest could be used as a diagnostic test during the pollen season. Dose-response curves with 10-fold increasing concentrations of timothy grass pollen (10-4 to 100 AU) were carried out.
  
  
  RESULTS
  Basophils were not activated spontaneously during the pollen season since the CD63 expression was below detectable levels before in vitro cell activation. A decreased percentage of activated basophils at the peak of activation was found in comparing the pre- and in-season tests, but all patients had a positive test. When basophil activation was at its peak, the allergen concentration was similar during the two periods. Moreover, the median area under the curve was significantly (P < 0.02) reduced during the season as compared to before the season.
  
  
  CONCLUSIONS
  Basotest can therefore be used as a diagnostic test during the pollen season, but the allergen exposure needs to be characterized if quantitative studies are performed.
authors.affiliation: INSERM U454-IFR3, Montpellier, France.
authors.forename: M
authors.initials: M
authors.lastname: Saporta
authors.forename: S
authors.initials: S
authors.lastname: Kamei
authors.forename: L
authors.initials: L
authors.lastname: Persi
authors.forename: J
authors.initials: J
authors.lastname: Bousquet
authors.forename: B
authors.initials: B
authors.lastname: Arnoux
mesh_terms: D000328:Adult; D000485:Allergens / Q000009:adverse effects* / Q000032:analysis / Q000276:immunology; D015703:Antigens, CD / Q000097:blood*; D001491:Basophils / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005602:France; D006801:Humans; D006967:Hypersensitivity / Q000097:blood / Q000175:diagnosis* / Q000209:etiology* / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008875:Middle Aged; D010980:Platelet Membrane Glycoproteins; D006109:Poaceae; D011058:Pollen / Q000009:adverse effects*; D012621:Seasons; D060149:Tetraspanin 30
chemical_list: D000485:Allergens; D015703:Antigens, CD; C554586:CD63 protein, human; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30; D007073:Immunoglobulin E