Standardizing a Four-Marker Basophil Activation Test: Influence of Storage Time, Temperature, and IgE Levels

Area of Science:

• Immunology
• Allergy Diagnostics
• Flow Cytometry

Background:

• Allergic diseases impact 25% globally, with current diagnostics lacking specificity.
• Basophil activation test (BAT) shows high specificity but needs methodological standardization.

Purpose of the Study:

• Develop an analytically validated BAT protocol for Dermatophagoides farinae (Df) allergy.
• Optimize gating strategies and pre-analytical storage conditions for BAT.

Main Methods:

• Enrolled 79 adults (Df-sensitized and controls).
• Assessed basophil activation via CD63 expression after Df extract, anti-IgE, or fMLP stimulation.
• Evaluated gating strategies, correlation with serological markers, and storage stability.

Main Results:

• A three-marker gating strategy demonstrated analytical equivalence to a four-marker approach, reducing costs by 25%.
• Df-induced BAT results showed moderate correlation with Df sIgE and membrane-bound IgE, explaining less than 40% of variability.
• Storage at 2-8°C preserved Df responsiveness up to 52 hours, while room temperature was better for fMLP.

Conclusions:

• A three-marker gating strategy in a four-color BAT panel is cost-effective and analytically equivalent.
• Stimulus-specific storage conditions support flexible processing for research.
• BAT offers functional information complementary to IgE levels, requiring prospective validation for clinical utility.