A Fully Automated Chemiluminescent Immunoassay for Component-Resolved Diagnosis of Pollen Allergy: Validation of Six CHORUS CLIA Assays.

Background/

Objectives

CHORUS CLIA "Allergy Components" is a novel line of fully automated assays designed to detect specific IgE directed against allergenic molecular components.

Methods

Six singleplex assays-here collectively named as CHORUS CLIA "Allergy Components"-were developed against molecular components of birch (Bet v 1, Bet v 2), timothy grass (Phl p 1, Phl p 5b, Phl p 7), and wall pellitory (Par J 2) and validated on the CHORUS EVO instrument using serum from patients with suspected IgE-mediated sensitization. Limits of detection (LoD) and quantitation (LoQ) were determined according to current guidelines. Comparative analyses of CHORUS CLIA "Allergy Components" with ImmunoCAP ISAC and ImmunoCAP Specific IgE were performed to assess diagnostic accuracy. Spearman's correlation, Passing-Bablok regression, and Bland-Altman analysis were used to evaluate correlation between methods.

Results

The LoD was 0.029 kU/L and the analytical interval, 0.10-50.0 kU/L, was validated by LoQ analyses. CHORUS CLIA "Allergy Components" showed high sensitivity (92.0-100.0%) and specificity (96.0-100.0%) versus ImmunoCAP ISAC. Furthermore, diagnostic accuracy was confirmed against ImmunoCAP Specific IgE (Cohen's kappa: 0.840-1.000). The Spearman coefficient ranged from 0.907 to 0.970 between CHORUS CLIA "Allergy Components" and ImmunoCAP ISAC, and from 0.903 to 0.989 versus ImmunoCAP Specific IgE. The Passing-Bablok analysis showed no differences, and the Bland-Altman analysis revealed outliers only among high-positive samples, without affecting the clinical interpretation.

Conclusions

The six assays of the CHORUS CLIA "Allergy Components" panel can detect IgE directed against major allergens from Betula verrucosa (birch), Phleum pratense (timothy grass), and Parietaria judaica (wall pellitory). These assays resulted accurate, reproducible, and specific, and showed substantial agreement with both ImmunoCAP ISAC and ImmunoCAP Specific IgE.