Effect of new macrolides on the expression of adhesion molecules on neutrophils in chronic sinusitis

To elucidate the mechanisms involved in the action of new macrolides on chronic sinusitis, we examined the effects of clarithromycin (CAM) and roxiythromycin (RXM) on the expression of adhesion molecules (L-selectin and Mac-1) on peripheral blood neutrophils of individuals with chronic sinusitis. The administration of CAM and RXM slightly inhibited the down-regulation of L-selectin expression on neutrophils induced by interleukin (IL)-8 stimulation. Furthermore, the administration of CAM strongly inhibited the IL-8-induced up-regulation of Mac-1 expression on neutrophils. These observations suggest that the new macrolides such as CAM and RXM may affect the functions of neutrophils in chronic sinusitis by modulating the expression of L-selectin and Mac-1 molecules on neutrophils, thereby attenuating the adhesion of neutrophils.