Diagnostic characterization of respiratory allergies by means of a
multiplex immunoassay.
Abstract
Background: Allergic sensitization is commonly assessed in patients by
performing the skin prick test (SPT) or determining specific IgE levels
in blood samples with the ImmunoCAP assay, which measures each allergen
and sample separately. This paper explores the possibility to
investigate respiratory allergies with a high throughput method, the
Meso Scale Discovery (MSD) multiplex immunoassay, measuring IgE levels
in low volumes of blood. Methods: The MSD multiplex immunoassay,
developed and optimized with standards and allergens from Radim, was
validated against the SPT and the ImmunoCAP assay. For 18 adults (15
respiratory allergy patients and 3 controls), blood collection and the
SPT were performed within the same hour. Results: Pearson correlations
and Bland-Altman analysis showed high comparability of the MSD multiplex
immunoassay and the ImmunoCAP assay, except for house dust mite. The
sensitivity of the MSD multiplexed assay was ≥75% for most allergens
compared to the SPT and ImmunoCAP assay. Additionally, the specificity
of the MSD multiplex immunoassay was ≥80% - the majority showing 100%
specificity. Only the rye allergen had a low specificity when compared
to the SPT, probably due to cross-reactivity. The reproducibility of the
MSD multiplex immunoassay, assessed as intra- and inter-assay
reproducibility and biological variability between different sampling
moments, showed significantly high correlations (r=0.943-1) for
all tested subjects (apart from subject 13; r=0.65-0.99).
Conclusion: The MSD multiplex immunoassay is a reliable method to detect
specific IgE levels against respiratory allergens in a multiplexed and
high throughput way, using blood samples as small as from a finger
prick.