Performance evaluation of a specific IgE assay developed for the ADVIA centaur immunoassay system.
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.
Petersen
Anita Birgit
AB
In Vitro Diagnostics Business Unit, ALK-Abelló, Denmark. AIP@dk.alk.abello.com
Gudmann
Pernille
P
Milvang-Grønager
Pernille
P
Mørkeberg
Rikke
R
Bøgestrand
Søren
S
Linneberg
Allan
A
Johansen
Niels
N
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
D000485:Allergens; D007073:Immunoglobulin E