title: Flow-cytometric cellular allergen stimulation test in latex allergy.
abstract: BACKGROUND
  The use of flow-cytometric basophil activation to different allergens has been recommended in recent years. In this study, we analyzed the diagnostic reliability of the flow-cytometric allergen stimulation test (FAST) after latex-specific stimulation in vitro. The diagnostic reliability of the technique was assessed as well as its correlation with other in vitro diagnostic parameters.
  
  
  METHODS
  43 patients allergic to latex with a positive history and skin test participated in the study. Thirty subjects (20 of them exposed to latex) with a negative history, skin tests and serum-specific IgE determination to latex were used as controls. In FAST the percentage of basophils that express CD63 as an activation marker after in vitro stimulation with allergen (latex) is determined by flow cytometry, following double labelling with the monoclonal antibodies anti-CD63-PE and anti-IgE FITC.
  
  
  RESULTS
  Intraclass correlation coefficient in FAST with latex was 0.995 (p < 0.0001), which demonstrates the excellent reproducibility of this technique. Taking a cutoff point of 10% by means of ROC curves, FAST yields a sensitivity of 93% and a specificity of 100%. The FAST positive predictive value in latex allergy was 100% and the negative predictive value was 99.9%. We found a positive and significant correlation between FAST and specific IgE (CAP) with the histamine release test and specific sulphidoleukotriene production [cellular allergen stimulation test (CAST); p < 0.05].
  
  
  CONCLUSIONS
  FAST is a highly reliable technique (93% sensitivity and 100% specificity) in the in vitro diagnosis of IgE-mediated latex allergy.
authors.affiliation: Department of Allergology and Clinical Immunology, School of Medicine, University of Navarra, Pamplona, Spain. mlsanzlar@unav.es
authors.forename: María L
authors.initials: ML
authors.lastname: Sanz
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Gamboa
authors.forename: Carmen
authors.initials: C
authors.lastname: García-Avilés
authors.forename: Leticia
authors.initials: L
authors.lastname: Vila
authors.forename: Isauro
authors.initials: I
authors.lastname: Diéguez
authors.forename: Ignacio
authors.initials: I
authors.lastname: Antépara
authors.forename: Alain L
authors.initials: AL
authors.lastname: de Weck
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology*; D001491:Basophils / Q000502:physiology*; D002648:Child; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D020315:Latex Hypersensitivity / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged
chemical_list: D000485:Allergens