Quantitative flow cytometric analysis of the effects of cetirizine on the expression of ICAM-1/CD54 on primary cultured nasal cells

An in vitro flow cytometric model has been developed to evaluate the effect s of antiallergic drugs such as cetirizine (CTZ) on the expression of surfa ce molecules on primary cultured normal cells. Quantitative analysis demons trated that HLA class I and ICAM-1/CD54 molecules are present on both epith elial and stromal cells, and that their expression is strongly enhanced by treatment with interferongamma (IFN-gamma). Nevertheless, the IFN-gamma-med iated upregulation of ICAM-1/CD54 was inhibited by treatment with CTZ, demo nstrating a direct effect on both cell types. This finding is particularly interesting because ICAM-1/CD54 is the main rhinovirus receptor, and rhinov iruses are the principal cause of asthma exacerbation in children. Thus, ac cording to data derived from this in vitro model, CTZ should have an import ant role in the reduction of infectious exacerbation of asthma in atopic pa tients.