Optimizing of the Basophil Activation Test: Comparison of Different Basophil Identification Markers

BackgroundFlowcytometric identification of basophils is a prerequisite for measuring activation of basophils with IgE-dependent or IgE-independent stimuli. Aim of this study was to compare different marker combinations in a simultaneous multicolor flowcytometric measurement. MethodsTen patients with a grass pollen allergy and three controls were included in the study. Basophilic cells were gated by using anti-CCR3, anti-IgE, anti-CRTH2, anti-CD203c, and anti-CD3. Cells were activated by a monoclonal anti-Fc epsilon RI antibody, N-formyl-methionyl-leucyl-phenylalanine (fMLP), and the allergen extract Phleum pratense. The activation marker anti-CD63 was used. ResultsThe highest relative number of basophils was found with anti-CCR3(+) cells, anti-IgE(+) and anti-IgE(+)/anti-CD203c(+) cells, the lowest with CRTH2(+)/CD203c(+)/CD3(-) cells. A very good and good concordance of CCR3(+) cells was seen with CCR3(+)/CD3(-) cells and CRTH2(+)/CD203c(+)/CD3(-) cells in all experiments. The contamination of the CCR3(+) population with CD3(+) cells and the contamination of the IgE(+)-population with CCR3(-) cells and CD203(-) cells were the lowest compared to all other marker combinations. ConclusionsAs the highest relative number of basophils was identified by anti-CCR3 followed by the anti-IgE and anti-IgE/antiCD203c positive population in most cases, these markers can generally be recommended for identification of basophils. If a basophil population with very high purity is needed, anti-IgE should be chosen. (c) 2014 International Clinical Cytometry Society