EPITHELIAL-CELL PROLIFERATION IN NASAL POLYPS COULD BE UP-REGULATED BY PLATELET-DERIVED GROWTH-FACTOR

The modifications of epithelial differentiation and proliferation obse rved in nasal polyps (NP) could be related to local secretion of growt h factors, among which platelet-derived growth factor (PDGF) could pla y a key role. We therefore prospectively studied, by immunohistochemis try, proliferating cell nuclear antigen (PCNA, and S-phase cell marker ), PDGF, and CD-68 (activated macrophages marker) expression in NP and inferior turbinate mucosa (NM) in 11 patients. Our data show that PCN A and PDGF expression are increased in NP epithelium, while CD-68 expr ession is increased in NP epithelium and lamina propria when compared to NM. Increased local PDGF secretion by numerous activated macrophage s could therefore be involved in epithelial cell proliferation up-regu lation in NP. PDGF could also be involved in the pathogenesis of NP vi a its connective tissue remodeling actions.