title: Reliability of basophil activation test using CD203c expression in diagnosis of pollen allergy.
abstract: BACKGROUND
  CD203c is a basophil surface marker and its expression is rapidly up-regulated after cross-linking of high-affinity immunoglobulin E (IgE) receptor (FcepsilonR1) by an allergen. CD203c basophil activation tests have been studied for the in vitro diagnosis  of several allergic conditions. However, there is limited data about its diagnostic usefulness. The optimum allergen concentrations for stimulation and allergen specific cutoff values remain unknown for a number of allergens. This study was designed to investigate the efficacy of basophil  activation test via CD203c in the diagnosis of pollen allergy.
  
  
  METHODS
  The CD203c basophil activation was determined in 31 allergic rhinitis patients with pollen allergy and 9 healthy nonatopic controls during the off-season. CD203c expression was evaluated using  three-color staining protocol by flow cytometry.
  
  
  RESULTS
  After an in vitro stimulation with grass pollen extract, the CD203c assay clearly discriminated pollen-allergic patients from controls (p < 0.001). A dose-dependent increase in the percentages of CD203c-activated  basophils was shown in rhinitis patients with pollen allergy (p < 0.001). The sensitivity and specificity was 100% and optimal cutoff values were 14.05 and 10.05% with 45.1 and 4.5 μg/mL Phl p 5 stimulation, respectively. Although the specificity was also 100%, the sensitivity was 93  and 87% and the cutoff values were 5.40 and 5.35% with 4.5 × 10(-4) and 4.5 × 10(-5) micrograms/mL Phl p 5 stimulation, respectively.
  
  
  CONCLUSIONS
  The CD203c basophil activation test seems to be a reliable tool in the diagnosis  of grass pollen allergy. It could be used when conventional diagnostic tests fail or can not be performed.
authors.affiliation: Division of Immunology and Allergy Diseases, Ankara University School of Medicine, Ankara, Turkey. secilkepil@gmail.com
authors.forename: Seçil Kepil
authors.initials: SK
authors.lastname: Özdemir
authors.forename: Deniz
authors.initials: D
authors.lastname: Güloğlu
authors.forename: Betül A
authors.initials: BA
authors.lastname: Sin
authors.forename: Atilla H
authors.initials: AH
authors.lastname: Elhan
authors.forename: Aydan
authors.initials: A
authors.lastname: Ikincioğulları
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Mısırlıgil
mesh_terms: D000328:Adult; D015549:Basophil Degranulation Test; D001491:Basophils / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007114:Immunization; D008297:Male; D008875:Middle Aged; D010727:Phosphoric Diester Hydrolases / Q000032:analysis*; D010936:Plant Extracts / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology; D006109:Poaceae; D011058:Pollen / Q000276:immunology; D011237:Predictive Value of Tests; D011379:Prognosis; D011755:Pyrophosphatases / Q000032:analysis*; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D012680:Sensitivity and Specificity
chemical_list: C427944:ENPP3 protein, human; C076049:Phl p V protein, Phleum pratense; D010936:Plant Extracts; D010940:Plant Proteins; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases