Practical issues Recommendations Implications for clinical trials
Basophil reactivity is reduced over time29.
Perform BAT within a few hours (up to 24h) of blood collection
Good transportation system between sites to ensure timely delivery of samples. Test samples of all site within the same time frame.
Basophil reactivity can be affected by vibration and changes in temperature29.
Ensure method of transportation that ensure stability of temperature transfer of samples.
Prefer transport system with temperature control for samples.
Immunosupressors, including oral corticosteroids, can reduce basophil response30.
Avoid immunosupressors before blood collection for BAT.
Need to continue treatment with immunosupressors should be an exclusion criteria of studies using BAT.
Exposure to allergen, chronic inflammation and infection can induce basophil degranulation and homing to the tissues101.
Avoid performing BAT after allergen exposure or during infection or chronic inflammatory condition.
Blood for BAT needs to be collected prior to allergen exposure (namely challenge but not SPT). Active infections inflammatory conditions should be an exclusion criteria of studies using BAT.
Basophil activation can vary with the anticoagulant used29. BAT can be performed in blood collected into heparin or EDTA. Blood for BAT should be collected using the same material and methodology during studies and between sites.
Measurement of basophil activation can be influenced by the markers used to identify the basophils, by the BAT protocol and by flow cytometry4. BAT should be performed with a validated method and optimised conditions. The same reagents and protocol should be used throughout a clinical trial and flow cytometers should be standardized.
Quantification of basophil activation can vary with the method adopted for data analyses4,32. Criteria should be defined for each step of data analyses. Automated data analyses can be considered. The exact same methodology needs to be used between centers and throughout the clinical trial.