EXPRESSION OF INTERCELLULAR-ADHESION MOLECULE-1 ON THE VASCULAR ENDOTHELIUM IN NASAL POLYPS BEFORE, DURING AND AFTER TOPICAL GLUCOCORTICOIDTREATMENT

Nasal polyposis is a result of a chronic inflammatory disorder in the upper airways. In vitro studies have revealed that extravasation of le ucocytes requires interactions between several sets of adhesion molecu les expressed on the circulating leucocytes and the vascular endotheli um. Therefore, the endothelial expression of intercellular adhesion mo lecule-1 (ICAM-1) in biopsies from polyps and inferior turbinates was investigated by the use of immunohistochemical staining. Biopsies were obtained from 11 patients suffering from nasal polyposis before, duri ng and after treatment with 100 mu g budesonide (Rhinocort(R) Turbuhal er(R)) in each nostril twice daily. Before, during and after treatment , ICAM-1 was expressed in the majority of vessels in polyps and mucosa of inferior turbinates. The intensity of endothelial ICAM-1 expressio n in polyps was significantly reduced during topical glucocorticoid tr eatment compared with the pretreatment and posttreatment levels (p < 0 .005). In biopsies from the inferior turbinates, the intensity of the endothelial ICAM-1 expression was lower during treatment than after di scontinuation of medical treatment (p < 0.005). In conclusion, topical budesonide treatment seems to downregulate ICAM-1 expression on the v ascular endothelium in nasal polyps. Such an effect may interfere with leucocyte extravasation and partially account for the anti-inflammato ry effect of local glucocorticoid treatment in human nasal polyposis.