Basophil activation test
Blood basophils express high levels of FcεRI that have bound IgE. To determine sensitization, basophils are incubated in vitro with allergen, followed by examination of degranulation. Fusion of granules to the cell membrane leads to upregulation of surface markers CD63 and CD203c, which are indicative of specific IgE functional activity. In patients with AR undergoing SLIT, basophil activation decreased with clinical efficacy.247 Similar decreases occurred in patients undergoing peanut immunotherapy.234 However, in grass pollen SLIT, basophil activation did not correlate with clinical efficacy (Table 2).248