Validation study of a new chemiluminescent singleplex IgE assay in a set of Italian allergic rhinitis patients

Abstract

Background: The measurement of specific IgE to allergenic extracts and molecules in patients with allergic rhinitis (AR) is crucial for a precise diagnosis and further immunotherapy. Companies providing in vitro diagnostic methods in allergology continuously strive for the optimization and modernization of such methods. A new generation of automated allergy tests based on chemiluminescence detection and paramagnetic microparticles is now available, with possible advantages in sample volume, cost-effectiveness and avoidance of sample-related interference. Objectives: To test whether sIgE antibody levels obtained with a new singleplex chemiluminescent method have a good agreement with the corresponding results obtained with a “gold standard” test. Methods: We tested sera from 368 AR patients. Specific IgE sera levels (kU/L) to a comprehensive panel of 15 allergen extracts and 6 molecules were tested with ImmunoCAP® (Thermo Fisher Scientific Inc, Phadia AB, Uppsala, Sweden) and NOVEOS™ (HYCOR® Biomedical, Garden Grove, CA, USA). We evaluated the qualitative and quantitative performance of the new NOVEOS system in matching the outcome of ImmunoCAP to each of the examined allergens. Results: In relation to ImmunoCAP, the overall diagnostic sensitivity and specificity of sIgE tests with NOVEOS were 90.8% (95% CI = 88.6–92.7) and 96.2% (95% CI = 93.9–97.8), respectively. These values were higher when only molecules were considered (sensitivity = 98.7% [95% CI = 96.4%–99.7%]; specificity = 94.2% [95% CI = 88.4%–97.6%]) and lower when only extracts were considered (sensitivity = 87.6% [95% CI = 84.7%–90.2%]; specificity = 97% [95% CI = 94.4%–98.6%]). Spearman's correlation between the data set of both methods for a ≥ 0.1 kU/L cut-off was 0.84 (p