[Serum level of soluble ICAM-1 in subjects with nasal allergy and ICAM-1 mRNA expression in nasal mucosa].

Intercellular adhesion molecule-1 (ICAM-1) has been reported to be instrumental in airway eosinophils and airway hyperreactivity. In nasal mucosa, ICAM-1 molecule is observed on the endothelium, around the nasal gland and just below the epithelium. In this study, we investigated the gene expression of ICAM-1 in nasal mucosa and the serum level of soluble ICAM-1. In subjects with nasal allergy sensitized with house dust, a pair of house dust antigen discs were placed on the inferior nasal mucosa on one side, while control discs free of antigen were placed on the other side. After six hours, the inferior nasal mucosa were bilaterally obtained separately. By Southern blot analysis following a reverse-transcription polymerase chain reaction, we detected ICAM-1 messenger RNA (mRNA) in the nasal mucosa. Although the expression of ICAM-1 mRNA was already observed in the nasal mucosa without antigen challenge, it increased six hours after the challenge. The serum level of immunoreactive soluble ICAM-1 in the subjects with nasal allergy and normal subjects was evaluated by sandwich enzyme-linked immunosorbent assay. The serum level of soluble ICAM-1 in the subjects with nasal allergy was 380.7 +/- 105.2 ng/ml. It was significantly higher than that of the normal control, which was 278.6 +/- 64.6 ng/ml. These results suggested that the increased expression of ICAM-1 may contribute to the pathogenesis of nasal allergy by facilitating the infiltration of inflammatory cells such as eosinophils and their functional activities.