NEW FLOW CYTOMETRIC METHOD FOR SURFACE PHENOTYPING BASOPHILS FROM PERIPHERAL-BLOOD

To clarify the role of basophils in the pathogenesis of allergic disea se, we developed a new method for performing surface phenotyping of th ese cells in centrifugation-enriched mononuclear cell fraction. This m ethod identified basophils on the basic of a negative reactivity with mixed FITC-conjugated monoclonal anti-bodies (mAbs) (anti-CD2, -CD14, -CD16, and -CD19) with analysis performed by flow cytometry. The valid ity of this approach was confirmed by sorting experiments. Various PE- conjugated mAbs were also used to examine binding to FITC-negative bas ophils. Basophils from asthmatic patients (n = 14) as well as from nor mal subjects (n = 6) were shown to express CDw32 (FcgammaRII), CD25 (I L-2R), but not CD64 (FcgammaRI). We also detected binding of IgG1 and IgG4 to basophils. This method of phenotyping was very rapid and simpl e. It thus appears to be useful in the study of allergic disease, as w ell as of the biology of the basophil.