BACKGROUND: Up-regulation of matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF) beta, may contribute to the formation of nasal polyps (NPs). Rhinovirus (RV) infection enhances expression of MMP-2, MMP-9, and VEGF in NP fibroblasts and of TGF-beta in respiratory epithelial cells. We investigated the inhibitory effects of levocetirizine (LCT) on the RV-induced expression of (1) fibrogenic (MMPs and TGF-beta) and (2) angiogenic (VEGF and TGF-beta) factors in NP fibroblasts. METHODS: NP fibroblasts obtained from 11 male patients with chronic rhinosinusitis with NPs (CRSwNPs), were infected with RV serotype 16 (RV-16) for 4 hours. Cells were treated with 50 nM of LCT 24 hours before infection and for 48 hours thereafter. Expression of MMP-2, MMP-9, VEGF, and TGF-beta mRNA and protein were determined by real-time polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. RESULTS: LCT significantly inhibited RV-induced increases in MMP-2, MMP-9, VEGF, and TGF-beta mRNA, and protein expression, in NP fibroblasts (p < 0.05 for each comparison). CONCLUSION: LCT inhibits RV-induced up-regulation of fibrogenic and angiogenic factors in NP fibroblasts, suggesting that LCT may prevent NP formation in patients with CRSwNP caused by RV infection.