D3.72 - Utility of Basophil Activation Testing in Drug and Peanut Allergy: Concordance with Clinical Outcomes

The Basophil Activation Test (BAT) is a novel diagnostic tool for evaluating IgE-mediated hypersensitivity reactions. It may serve as a complementary diagnostic method to conventional methods such as skin prick tests (SPT), intradermal tests (IDT), and serum-specific IgE (sIgE) assays. However, BAT is not widely available in clinical immunology laboratories. This study sought to assess the diagnostic efficacy of BAT in comparison to SPT, IDT, and sIgE in children with suspected peanut allergy and various antibiotic allergies.

Methods

Among six children with suspected peanut allergy, two had true negative BAT results, while one had a true positive result. Two patients were classified as “immunologic grey zones” and have not yet undergone an oral food challenge, while one relocated to another country.

BAT was performed for nine different medications in 17 paediatric patients, categorized into four main drug classes: antibiotics, neuromuscular blockers, antiseptics, and anti-emetics. Correlation analysis revealed that 80% (N=15) of patients had concordant negative results between BAT and SPT. Out of these, two had failed the challenge, suggesting that neither SPT nor BAT was sensitive enough to detect the allergy. In contrast, BAT and IDT exhibited significant discrepancies, with conflicting results observed in 60% (N=10) of cases in comparison to challenge outcomes.

Results

Among six children with suspected peanut allergy, two had true negative BAT results, while one had a true positive result. Two patients were classified as “immunologic grey zones” and have not yet undergone an oral food challenge, while one relocated to another country. BAT was performed for nine different medications in 17 paediatric patients, categorized into four main drug classes: antibiotics, neuromuscular blockers, antiseptics, and anti-emetics. Correlation analysis revealed that 80% (N=15) of patients had concordant negative results between BAT and SPT. In contrast, BAT and IDT exhibited significant discrepancies, with conflicting results observed in 61.6 % (N=14) of cases.

Conclusion

BAT exhibits limited sensitivity but moderate specificity in diagnosing IgE-mediated hypersensitivity reactions. While it demonstrates strong concordance with SPT in peanut allergy, its variability compared to IDT underscores the necessity for cautious interpretation, particularly in drug allergy assessment. The observed discrepancies indicate that BAT should not be employed in isolation but rather as an integral component of a comprehensive diagnostic strategy. Our findings concur with existing literature, reinforcing the notion that BAT can be a valuable adjunct but necessitates further validation in larger cohorts.