Basic and clinical immunology – 3025. Suppression of eosinphil activation by levocetirizine hydrochloride in vivo

Methods The influence of histamine H1 receptor antagonists on eosinophil functions was examined through the choice of levocetirizine hydrochloride (LH) in vivo.Patients with Japanese cedar pollinosis were orally treated with LH once a day at a single dose of 5 mg for two weeks during Japanese cedar pollen season (February 2012 to April 2012). Nasal secretions were obtained before and after treatment with the filter paper method. Eosinophil activation was assessed by measuring the levels of both ECP and MBP in nasal secretions by ELISA. We also examined the number of eosinophils in nasal secretions and IgE levels in peripheral blood obtained from patients before and after treatment with LH.