Cetirizine-induced downregulation of airway fibroblast proliferation and function: a rationale for a different approach to allergy treatment?

Recently, airway fibroblasts captured the attention of both allergists and basic scientists since they are no longer considered as mere bystanders, as far as allergic airway diseases are concerned. The aim of the present study was to assess the effects of different Cetirizine (Cet) concentrations (0.01, 0.05, 0.1 mg/ml) on human airway fibroblast proliferation and on CD54 expression. By means of flow cytometry analysis, we evaluated CD54 expression by airway fibroblasts in basal conditions or after gammaIFN stimulation in the presence of Cetirizine; we also evaluated the effect of the drug on cell proliferation by a [3H]thymidine incorporation assay. All of the tested doses of Cetirizine were able to significantly reduce CD54 upregulation induced by gammaIFN; concerning the fibroblast proliferation, we observed a dose-dependent inhibition of [3H]thymidine incorporation. These results show that Cetirizine exerts a biologic effect directly on human airway fibroblasts, suggesting a new rationale in the use of this compound.