A Novel Veterinary Molecular Multiplex Microarray Serological Allergen Test (Pet Allergy Xplorer; Nextmune) Versus Conventional Extract‐Based Serological (Idexx; Stallergenes Greer Laboratories) Versus Intradermal Allergen Testing in 59 Dogs With Ato
David Birchler, Michaela Austel, Frane BanovicABSTRACT
Background
The first veterinary multiplex molecular microarray serum allergy test (SAT), Pet Allergy Xplorer, is commercially available. However, no comparative evaluations of this test versus whole extract‐based SAT (eSAT) platforms and intradermal allergen testing (IDAT) currently exist.
Hypothesis/Objectives
Evaluate agreement between IDAT, conventional eSAT (Stallergenes Greer Laboratories) and extract and recombinant‐containing SAT (erSAT) for shared environmental allergens in atopic dogs.
Animals
Fifty‐four dogs with non‐seasonal (with or without seasonal exacerbation) and five dogs with seasonal atopic dermatitis were enrolled.
Materials and Methods
IDAT, eSAT and erSAT were performed on the same day. Two independent investigators (Inv A and Inv B) recorded IDAT results. Per manufacturer guidance, 80 and 300 enzyme‐linked immunosorbent assay (ELISA) absorbance units (eSAT80 and eSAT300) and 28 ng/mL (erSAT) were used as SAT cut‐off values. Cohen's kappa ( κ ) and prevalence‐adjusted bias‐adjusted kappa (PABAK) were used to test agreement.
Results
Between IDAT investigators, there was almost perfect agreement across all allergens ( κ = 0.81; PABAK = 0.87). Moderate agreement ( κ = 0.58) between erSAT and eSAT300 across all allergens improved to almost perfect with PABAK (0.84). IDAT Inv A had the strongest agreement with eSAT300 ( κ = 0.44, PABAK = 0.75) compared to erSAT ( κ = 0.29, PABAK = 0.64) and eSAT80 ( κ = 0.13, PABAK = 0.11); results were similar with Inv B.
Conclusions and Clinical Relevance
Agreement between testing platforms varied depending on the kappa statistic used, with low κ agreement for most comparisons, highlighting disagreements on what was considered positive. PABAK was generally higher, showcasing high overall concordance. Agreement to the new erSAT was strongest with eSAT300; agreement was moderate ( κ ) to almost perfect (PABAK).