title: Performance evaluation of a specific IgE assay developed for the ADVIA centaur immunoassay system.
abstract: OBJECTIVE
  To develop and evaluate a liquid phase immunoassay for accurate determination of allergen-specific IgE (sIgE) as a useful tool in the diagnosis of allergy patients.
  
  
  METHODS
  A fully automated, quantitative sIgE assay was developed for the ADVIA Centaur technology platform using a unique calibration method based on a recombinant reference allergen. Compared to most other IgE-assays, the assay employs a reverse sandwich architecture using monoclonal mouse anti-human IgE antibody covalently bound to paramagnetic particles in the solid phase and capturing the sample IgE. Bound sIgE reacts with liquid biotin-labeled allergen, which is detected as chemiluminescence using acridiniumester-labeled streptavidin.
  
  
  RESULTS
  The ADVIA Centaur sIgE assay (Centaur assay) has exclusive reactivity to human IgE and performs with excellent linearity in the assay range 0.35-100 kU/L and high precision (imprecision within-run <2.6%, between-run <4.9%, and total imprecision <7.1%). The analytical sensitivity is <0.10 kU/L. Using Pharmacia CAP system FEIA (CAP) as a comparative method, positive/negative concordance was 94% at 0.35 kU/L cut-off, and the Centaur assay has a sensitivity of 90% and a specificity of 98%. Validation of the assay in a general population sample (The Copenhagen allergy study) revealed that sIgE was highly associated with a clinical diagnosis of inhalation allergy.
  
  
  CONCLUSIONS
  The Centaur assay is an allergen-specific assay for measurement of IgE without interference from other types of immunoglobulins or nonspecific IgE. The assay performs with a linear reaction, high assay range, and good reproducibility. The assay correlates well with the CAP system and is in agreement with clinical diagnosis.
authors.affiliation: In Vitro Diagnostics Business Unit, ALK-Abelló, Denmark. AIP@dk.alk.abello.com
authors.forename: Anita Birgit
authors.initials: AB
authors.lastname: Petersen
authors.forename: Pernille
authors.initials: P
authors.lastname: Gudmann
authors.forename: Pernille
authors.initials: P
authors.lastname: Milvang-Grønager
authors.forename: Rikke
authors.initials: R
authors.lastname: Mørkeberg
authors.forename: Søren
authors.initials: S
authors.lastname: Bøgestrand
authors.forename: Allan
authors.initials: A
authors.lastname: Linneberg
authors.forename: Niels
authors.initials: N
authors.lastname: Johansen
mesh_terms: D000485:Allergens / Q000276:immunology; D001331:Automation; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007118:Immunoassay / Q000379:methods*; D007073:Immunoglobulin E / Q000097:blood*; D008163:Luminescent Measurements; D008280:Magnetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000485:Allergens; D007073:Immunoglobulin E