Combining avidin with CD63 improves basophil activation test accuracy in classifying peanut allergy

Area of Science:

• Immunology
• Allergy Diagnostics
• Flow Cytometry

Background:

• Conventional basophil activation tests (BATs) utilize CD63 expression to detect basophil activation.
• Avidin, a positively-charged molecule, binds to activated basophils exposing negatively charged granule constituents during degranulation.
• This study compares avidin and CD63 as biomarkers for peanut allergy classification.

Purpose of the Study:

• To compare avidin binding and CD63 expression as basophil activation biomarkers.
• To evaluate their efficacy in classifying peanut allergy.
• To determine if combining avidin and CD63 improves diagnostic accuracy.

Main Methods:

• Seventy subjects (47 peanut allergy, 6 other food allergy, 17 non-allergic) underwent BATs.
• Basophils were stimulated with peanut extract (PE) and controls, with avidin binding and CD63 expression measured via flow cytometry.
• Logistic regression and XGBoost models were used for classification and feature identification.

Main Results:

• Avidin binding correlated with CD63 expression, and both markers distinguished peanut-allergic from non-allergic subjects.
• A distinct avidin+/CD63- subset was observed in all allergic subjects.
• Combining avidin and CD63 yielded high classification accuracy (97.8% sensitivity, 96.7% specificity).

Conclusions:

• Avidin and CD63 are validated BAT activation markers linked to basophil degranulation.
• Their combined use offers a more comprehensive identification of activated basophils.
• Combining avidin and CD63 significantly enhances peanut allergy classification accuracy.