Inhibitory Action of Azelastine on Cytokine Production from Human Peripheral Blood Leukocytes in Vitro

Effects of azelastine (AZ) on human peripheral blood leukocytes (PBL) in culture were examined. Addition of 10.0 micrograms/ml of AZ resulted in a marked inhibition of PBL blastic activity, but lower concentrations (1.0 and 0.5 microgram/ml) had no demonstrable suppressive effects on the activation. Interleukin (IL)-2, IL-3 and IL-4 production from PBL in response to Concanavalin A stimulation was also strongly suppressed when the cells were cultured in the presence of AZ. This suppression was observed even when lower concentrations (1.0 and 0.5 microgram/ml) of AZ were added to cell cultures.