Flow Cytometric Allergy Diagnosis: Basophil Activation Techniques.

The basis of flow cytometric allergy diagnosis is the quantification of changes in the expression of basophilic surface membrane markers (Ebo et al., Clin Exp Allergy 34: 332-339, 2004). Upon encountering specific allergens recognized by surface receptor FcεRI-bound IgE, basophils not only secrete and generate quantifiable bioactive mediators but also upregulate the expression of different markers (e.g., CD63, CD203c) which can be detected by multicolor flow cytometry using specific monoclonal antibodies (Ebo et al., Cytometry B Clin Cytom 74: 201-210, 2008). Here, we describe two flow cytometry-based protocols which allow the detection of surface marker activation (Method 1) and changes in intragranular histamine (Method 2), both reflecting different facets of basophil activation.