Conclusion

By generating progenitor-cell derived basophils in high-yield we have developed a flow cytometry-based basophil activation test for use with stored serum which can be used to assess reactivity to both food and inhalant allergens. By incorporating fluorescent barcoding, we have increased the throughput of the assay, reducing costs significantly. We identified wide variability in trajectories of response to allergen in different subjects, and responses were muted in the presence of the anti-IgE treatment omalizumab, indicating that this test better reflects the overall immune milieu rather than just specific IgE. For subjects who had undergone oral food challenge to peanut, we were able to use results of PCBAT to predict clinical reactivity to peanut. The correlation of PCBAT to clinical reactivity to inhaled cat allergen may represent a safe and robust way of identifying those asthmatics who might benefit from interventions for ongoing cat allergen exposure. Although further evaluation is required, this proof of concept study indicates that this test may have a role in food and inhalant allergy testing as a means of identifying clinically important sensitisations.
Table I Demographic description of the study groups.