Role of vascular endothelial growth factor in the pathogenesis of nasal polyps.

OBJECTIVE: This study was aimed at determining the expression of vascular endothelial growth factor (VEGF) in nasal polyps by immunohistochemical technique.

METHODS: The study group consisted of 25 adult patients with nasal polyps who underwent functional endoscopic sinus surgery. Polyp tissues were taken from the maxillary and ethmoid sinuseses and the nasal cavity. The control group consisted of three adult patients without nasal polyps who underwent septoplasty operation. Their inferior turbinate biopsies were taken with written approval. VEGF positivity was scored by the Vascular Endothelial Growth Factor Positivity Index (VEGF-PI) in the subepithelial (VEGF-PI-SE) and deep (VEGF-PI-Deep) layers of the mucosa on a 0 to 3 scale, and the percentage of inflammatory cells per 100 cells was found.

RESULTS: VEGF expression was identified as cytoplasmic staining in the vascular endothelium and inflammatory cells. In each of four groups (maxillary and ethmoid sinuses, nasal cavity, and control), no significant difference was present between VEGF-PI-SE and VEGF-PI-Deep scores. For the VEGF-PI-SE and VEGF-PI-Deep groups, nasal cavity scores were significantly higher. For plasma cell count, the nasal cavity value was significantly higher. As the plasma cell count increased, VEGF-PI-SE and VEGF-PI-Deep scores were also increased in all four groups.

CONCLUSION: In the nasal cavity, VEGF expression is observed more, causing angiogenesis and an increase in the vascular permeability. In the paranasal sinuses, lower VEGF-PI results may show that contact inhibition reduces VEGF expression and thus the polyp growth rate.