Basophil activation test in food allergy: where are we now?

PURPOSE OF REVIEW: To highlight the most recent findings on the basophil activation test (BAT) in food allergy, with a focus on advances in assay standardization and logistics, and on emerging clinical applications across major allergens aimed at improving diagnostic accuracy and reducing the need for oral food challenges.

RECENT FINDINGS: Recent literature supports BAT as a useful tool to complement history, skin prick testing, and specific IgE, particularly in equivocal cases where oral food challenge (OFC) would otherwise be required. Evidence is strongest for peanut and sesame, with expanding data for milk, egg, and tree nuts, including algorithm-based approaches for cross-reactive nuts. Methodological advances include delayed processing strategies, streamlined multicentre workflows, and passive/indirect BAT approaches, alongside international initiatives aimed at harmonizing performance across laboratories. However, nonresponder rates, lack of universal thresholds, and heterogeneous performance between foods remain key limitations, and severity prediction is inconsistent across settings.

SUMMARY: BAT can enhance diagnostic certainty and may reduce OFC use in selected scenarios, but broader implementation requires harmonized protocols, prospective validation of clinically actionable cut-offs, and robust multicentre outcome studies.