title: Basophil allergen threshold sensitivity, CD-sens, is a measure of allergen sensitivity in asthma.
abstract: BACKGROUND
  Allergic asthma is IgE-mediated and the IgE-sensitisation is usually demonstrated by skin prick tests (SPT) and IgE antibody determinations in serum. The SPT and IgE-antibody values do not directly predict if the allergy clinically contributes to the asthma. There is therefore a need for new objective tests that may indicate the clinical importance of an IgE-sensitisation.
  
  
  OBJECTIVE
  To evaluate basophil allergen threshold sensitivity (CD-sens) as a measure of allergen sensitivity in allergic asthma.
  
  
  METHODS
  Twenty-six subjects with stable, intermittent allergic asthma were tested with SPT and spirometry, and methacholine and allergen inhalation challenges to determine methacholine PD(20) (provocative dose causing a 20% drop in forced expiratory volume in 1 s) and allergen PD(20) . The results were compared with CD-sens and serological parameters, i.e. IgE- and IgG4 antibodies to the relevant allergens.
  
  
  RESULTS
  A significant correlation was found between CD-sens and allergen PD(20) (P = 0.01; r = 0.49; n = 26) as well as between CD-sens and the ratio of allergen PD(20) to methacholine PD(20) (P = 0.007; r = 0.52; n = 26). In patients with a moderate to low degree of bronchial hyperresponsiveness there was an excellent correlation (P = 0.0001; r = 0.88, n = 13) between CD-sens and allergen sensitivity. No relation to either allergen PD(20) or the ratio was found for basophil allergen reactivity measured as CD63 up-regulation at high concentrations of the respective allergen.
  
  
  CONCLUSIONS
  CD-sens was found to be an objective marker of airway allergen sensitivity in stable allergic asthmatics, that may be used to predict airway responsiveness when bronchial challenge tests cannot be performed.
authors.affiliation: Department of Medicine, Division of Respiratory Medicine and Allergy Research, Karolinska University Hospital, Huddinge, Sweden. barbro.dahlen@ki.se
authors.forename: B
authors.initials: B
authors.lastname: Dahlén
authors.forename: A
authors.initials: A
authors.lastname: Nopp
authors.forename: S G O
authors.initials: SG
authors.lastname: Johansson
authors.forename: M
authors.initials: M
authors.lastname: Eduards
authors.forename: M
authors.initials: M
authors.lastname: Skedinger
authors.forename: J
authors.initials: J
authors.lastname: Adédoyin
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000276:immunology*; D001491:Basophils / Q000276:immunology*; D005260:Female; D006801:Humans; D007159:Immunologic Tests; D019570:Inhalation Exposure; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage / Q000009:adverse effects; D008875:Middle Aged; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000485:Allergens; D016210:Methacholine Chloride