Search

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 <.001). Conclusions: The new singleplex NOVEOS system presented good results for qualitative and quantitative comparisons when testing specific serum IgE antibodies against a range of 21 allergens. This novel immunoassay system using only 4 µl of sample per test appears to be robust and reliable and can, therefore, be used as an aid in allergy diagnosis. [ABSTRACT FROM AUTHOR]

Summary: Background: The identification of the primary sensitizing pollen is difficult in Southern European patients with Seasonal Allergic Rhinitis (SAR) if sensitized to various pollen sources with overlapping seasonality. A more precise diagnosis is obtained by IgE assays to allergen molecules, currently available as singleplex or microarrays. Objectives: To test the analytical performance of a multi‐parameter immunoblot molecular "Pollen Test" specifically designed to test IgE antibodies to pollen extracts and molecules clinically relevant in Southern Europe. Methods: Sera were obtained from 101 children and 98 adults with SAR and tested with a customized multiplex immunoblot assay (EUROLINE Southern European Pollen Profile [ESEP]; EUROIMMUN AG, Luebeck, Germany) containing a comprehensive panel of allergen extracts and molecules. ESEP's outcomes were then compared in selected sera (ESEP positive to negative = 2:1) with those of singleplex IgE assays (ImmunoCAP; ThermoFisher Scientific, Uppsala, Sweden). For each of the examined reagents, qualitative (sensitivity, specificity, accuracy), semi‐quantitative (classes) and quantitative (Spearman's rank correlation, Bland‐Altmann plots) comparisons were performed. Results: Compared to ImmunoCAP, cumulative ESEP's sensitivity and specificity were 87% (95% CI 84%‐90%) and 88% (83%‐93%) for extracts and 99% (98%‐100%) and 87% (83%‐91%) for molecules. Cohen's kappa coefficients (κC) ranged for extracts from 0.18 (Pellitory) to 0.50 (Cypress) and for molecules from 0.21 (Ole e 1) to 0.68 (Phl p 7). The quantitative outcomes of the two diagnostic tests were highly correlated, with Spearman's rank correlation coefficients always exceeding 0.80. Bland‐Altmann plots showed a tendency of ESEP to overestimate serum specific IgE levels, when compared to ImmunoCAP. Conclusions and clinical relevance: Sensitivity and specificity of ESEP in testing serum IgE antibodies against pollen allergen extracts and molecules, in Italian patients with SAR, both exceeded 85%. The advantages and limitations of a multiplex customized immunoblot assay, in the routine clinical use of molecular diagnostics in Southern European pollen allergic patients, deserve to be tested. [ABSTRACT FROM AUTHOR]