Nextmune Pet Allergy Xplorer

The first molecular IgE serum test for companion animals

PROBLEM

Allergy testing in veterinary medicine traditionally involves placing an allergen extract on an enzyme-linked immunosorbent assay (ELISA) plate, incubating it with serum, and then adding a reagent that recognizes immunoglobulin E (IgE). The resulting color change indicates the amount of IgE present.

This technique, used by veterinary laboratories worldwide, has remained unchanged for decades. However, the results can vary significantly depending on the extract used, and false-negative results may occur when the concentrations of clinically relevant allergenic proteins are too low.

For example, an extract of house dust mites—a common pet allergen—is produced by grinding mites, adding solvents to release allergenic proteins, and purifying those proteins.

House dust mites contain more than 10,000 proteins, but only about 40 proteins are known to cause allergic reactions. This means that when testing with a crude extract, only a small fraction of the allergy-causing proteins are represented—especially problematic when an animal has a low IgE level to a specific allergen. This can easily lead to false-negative results.

Moreover, extracts may vary not only between laboratories but even between batches of the same allergen, making result reproducibility difficult.
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SOLUTION

To obtain more accurate and sensitive information, tests are needed that identify each individual allergenic protein. Instead of testing whole house dust mites (or any other allergen) as a single extract, techniques must target the specific proteins responsible for allergic reactions.

Veterinary practitioners now use molecular allergology to determine which allergens truly cause problems, enabling them to provide their patients with a higher level of care.

The company Macro Array Diagnostics (MAD) developed the Allergy Explorer (ALEX) test, which provides a sensitization profile for human patients using a panel of allergen extracts and molecular allergen components.

Since its founding in 2016, MAD has launched two generations of ALEX and offers a panel that covers nearly 100% of clinically relevant allergens worldwide. The company has also developed the Food Xplorer (FOX) test to detect IgG-mediated food intolerances.

Molecular allergology instrument – Molecular allergology cartridge

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INNOVATION

Nextmune partnered with Macro Array Diagnostics to develop the Pet Allergy Xplorer (PAX) – the first commercial IgE-specific serological test that uses both allergen extracts and molecular components to identify allergens affecting companion animals.

Among the benefits are:

Improved reproducibility

A state-of-the-art robotic system assembles every ELISA test kit, providing a standardized manufacturing method that exceeds the reproducibility of traditional ELISA plates.
A standardized process is also used to produce allergen extracts, further improving result consistency.

Increased data capacity

Typical serum allergy testing provides about 90 results, and intradermal testing offers about 60–80 results.
The PAX cartridge contains 300 positions – 100 for extracts and 200 for molecular components.

Automated technology

Robots are used throughout the process to minimize human error.
Microarray spots on the plate are dispensed by a robot during production, and serum is pipetted by a robot during the testing phase.
Each PAX cartridge includes built-in controls to verify that the sample contains sufficient IgE for testing and to confirm proper cartridge use.

Improved treatment

The more accurate and sensitive results provided by PAX enhance the ability to perform effective hyposensitization therapy, giving animals greater relief.

Improved identification of cross-reactivity

By combining allergen extracts and molecular components in one test, PAX helps identify cross-reactivity between allergens.

Clarified polysensitization

When multiple allergens cause reactions, PAX helps identify the primary triggers.

Individualized results

Results provided to the veterinarian are region-specific and species-specific, making interpretation easier and more relevant.

Higher accuracy

PAX uses a single, well-characterized monoclonal anti-IgE antibody for detecting IgE in companion animals, ensuring consistent sensitivity.
It also uses CCD (Cross-reactive Carbohydrate Determinant) blocking technology.
In some cases, CCDs bind to IgE receptors and produce false-positive results.
PAX technology employs a blocker that prevents this binding.

Allergy tests that do not use CCD blockers may identify many irrelevant allergens.
The PAX approach ensures that only clinically relevant allergens are detected, preventing confusion and misinterpretation.

Ongoing development

The current PAX cartridges contain allergen components and extracts proven to have clinical relevance based on current research.
As testing continues, additional allergenic components may be discovered.

For example, if an extract consistently tests positive while individual molecular components test negative, it may indicate the presence of an unidentified allergen or cross-reactivity.
Such data help characterize new molecules to be added in future versions, driving innovation in pet allergy research.

Nextmune is currently the only veterinary diagnostic laboratory utilizing molecular allergology.
This next-generation test enables veterinarians to diagnose allergic animals with greater accuracy and sensitivity, supporting improved treatment strategies.

The first PAX test for dogs launched in April 2023, with cat and horse versions to follow.

Thierry Olivry, DrVet, PhD, DipECVD, DipACVD, Scientific Advisor and Project Leader

Dr. Olivry graduated from the University of Toulouse, France.
He completed his dermatology residency and PhD in Comparative Pathology at the University of California, Davis, and holds diplomas from both ACVD and ECVD.
He spent most of his career as a clinical scientist at North Carolina State University (USA), researching allergic and autoimmune skin diseases.
He now resides in Riga, Latvia.